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Subwoofer Alignment at The Redmoor Cincinnati

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Recently I had the opportunity to help my friend Nick work on the calibration of some new components at a great looking venue in Cincinnati called The Redmoor. We met on TeamViewer and recorded the entire thing so that it could serve as a combination of consultation and training. If you’d like my help on your project, you can schedule an appointment here.

In this post I’ll walk you through some of the EQ and crossover alignment steps we took.

Pre-production

First, gather materials. I checked Tracebook for the HDL10-A and STX828S. No luck. I found the GLL file for the HDL10-A on the RCF website, though. I opened that in the GLL viewer, built an array with the settings I expected to see, calculated the balloon, opened the transfer function, and exported it to a file.

The get the subwoofer data into my audio analyzer I used VituixCAD2 to convert the image on the spec sheet into response data. Then I imported everything into Crosslite.

The sub’s native response will allow me to experiment with different low-pass filters.

Next I needed to choose a target. Since we are looking at anechoic responses, it makes sense to use a flat target, but recently I have started using a +6dB slope in the low end because I have found that that will push the crossover region up, which is a better representation of what will happen in the field when someone inevitably turns up the subs.

I’ll start by inserting those filters recommended by the manufacturer.

Next I’ll apply some initial EQ and gain to make a better match of the target.

Should we design an overlap or unity crossover? Let’s do both!

Before I we even look at the phase graph, let’s measure some slopes. We know that the sub’s slope is 24dB/oct because it was a flat line before the LPF was inserted. Switching to view Data Pre in the bottom window, we can look at different HPF slopes on top of the HDL10-A response and find that it is 48dB/oct. This is a clue that the phase response of the main will be steeper than the sub.

Switching to the phase graph we find that that is in fact the case.

Let’s try adjusting the sub’s LPF to match the response of the main.

Now the sub is too steep. Let’s split the difference with 36dB/oct. Now we have a nice match with only about a 30º maximum phase offset between them.

The filter change required a small gain adjustment. Here’s the sum.

What should we do about that bump? We could leave it alone and say we like it, but let’s insert symmetrical filters to restore the response to the target.

Now let’s try the unity class crossover.

The HDL10-A already has a steep HPF so I am reticent to make it even steeper, but I need main and sub to meet at -6dB. I know that the DSP at The Redmoor is a Venu360 so we’ll only have access to basic EQ filters. Let’s try the least steep HPF available, 6dB/oct. I’ll adjusted the delay by 0.5ms for a slightly better phase alignment.

Let’s try a 12dB/oct option.

Let’s zoom in and compare them. Which one is better? I don’t know, but now we have some options.

Now let’s see how this actually played out in the field.

Production

We started by verifying all settings and taking eight measurements of the HDL10-A through their coverage area.

We applied EQ towards the target and took more measurements to verify the EQ and prepare for alignment. We exported averages from Smaart and imported them into Crosslite. Here’s the phase graph.

At this point I realized that we could have made our work a lot easier by starting out with a ground plane measurement very close to the speakers and without any processing to get cleaner data for alignment. But, we were running out of time so I decided to simply apply 3ms of delay to the sub and move forward with this solution.

Here’s what the final measurement looked like.

Post production

Let’s see if we can improve on the alignment I came up with in the field.

Interestingly, measured in the room, the HDL10-A appear to have a 24dB/oct slope, not 48dB/oct as expected. Maybe this is a result of one of the user definable settings on the back.

The STX828S appear to have an 18dB/oct slope, even though we used the recommended 24dB/oct slope on the LPF.

How can we equilize this relationship? 24 – 18 = 6, so we can add a 6dB/oct LPF to the sub, right?

But that will add another 3dB of attenuation at the cutoff frequency, which we don’t want because we are trying to simulate what would have happened if we would have used a different LPF from the beginning.

One option is to simply switch the LPF to zero magnitude. That will give us a steeper slope without affecting the magnitude. Of course the magnitude won’t be accurate, but we can still research the phase alignment.

The result is better alignment without any additional delay.

I should make it clear here that a zero magnitude filter is not something you would normally find in a DSP. It is a special kind of simulation that Crosslite offers for research purposes. The closest thing you would find in a DSP is an all-pass filter or within a variable architecture FIR filter.

How do we know if we are making an improvement? We can see the phase come into better alignment and we can see the sum go up, but I find it helpful to have a goal of perfection to compare it to. In SATlive you would load the Perfect Sum trace. The workaround I used in Crosslite was to simply import the data a second time, but this time without the phase.

In this graph you can the the perfect sum target with two delay options. Both of the options include the new zero magnitude LPF.

How do you prepare for crossover alignments?

Single channel RTA targets to improve your mixes

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How good is your live stream mix? What does it sound like on the audience end?

How do you quantify that? Loudness metrics are helpful. I discovered YouLean meter like a lot of other sound engineers who have been doing more broadcast gigs during the pandemic. I monitor the live stream on a mobile device on ear buds to experience what the target audience might be hearing.

I still found myself wishing I had another form of reference.

For live in-person events I normally leave Smaart running in two channel transfer function mode to keep track of how the sound in the room might be deviating from the mix I’m pushing out of the console. In broadcast, there is no second channel to compare.

Now that I think about it, I suppose there might be a clever way to set up a transfer function that references the console output and measures a streaming output, but would they stay in synch? Is it even coherent anymore? Anyway, I find myself mostly looking at RTA and Spectrograph graphs these days. If an annoying resonance comes up I can find it quickly, but otherwise I’m not sure how to take action on a single channel measurement.

It occured to me to create a target using some reference material. I can measure a quality broadcast that I enjoy or find something recommended by the client. Since having this idea I have had time to test both. Here’s a screen capture from a recent gig.

Create the target

Creating the target is relatively simple. Just play your reference material, measure it, and store it.

But if you’re like me, you enjoy a certain level of complexity. Maybe you’ve noticed.

Here’s how I did it.

  1. Record a WAV file of the reference material.
  2. Import it into Tonal Balance Control.
  3. Convert the JSON file into three separate spectrum measurements.
  4. Import them into Smaart.

Someone on FB recommended Later with Jools Holland from BBC2. I recorded some long clips of male dialogue with lavalier mics and male hip-hop with hand-held mics. You can imagine the many variations of microphone, mic placement, instrument, and style available.

Tonal Balance Control is a plugin you would typically insert on the master buss of your DAW to take a look at the average frequency spectrum of your mix and compare it to some common genre targets. It will also allow you to import an audio file to generate your own targets. Those targets are stored as JSON files on your computer.

The JSON files cannot be imported directly into Smaart. Smaart wants to see a column of frequency and magnitude values. You’ll need to reorganize the data. There aren’t that many values so you could do it manually, but I’ve been trying learn MATLAB so I decided to use that.

%% JSON to TXT
% Decode file
filename = 'your file path'; % File from Tonal Balance Control.
text = fileread(filename); % Read contents of file as text.
S = jsondecode(text); % Decode JSON-formatted text

% Convert structure to table
f = struct2cell(S.frequencies_hz.Value); % Convert structure to cell array.
f(1,:) = []; f=f.'; f=cell2mat(f); % Clean and convert to matrix.

% Pull out the three traces (high, mid, and low)
high = struct2cell(S.high_normalized_mag_dB.Value);
high(1,:) = []; high=high.'; high=cell2mat(high);
low = struct2cell(S.low_normalized_mag_dB.Value);
low(1,:) = []; low=low.'; low=cell2mat(low);
mid = struct2cell(S.normalized_mag_dB.Value);
mid(1,:) = []; mid=mid.'; mid=cell2mat(mid);

% I ran makima here to make sure the frequency resolution matches that of Smaart, but it's probably optional.

% Create tables
highTbl = table(f,high,'VariableNames',{'frequency','magnitude'});
lowTbl = table(f,low,'VariableNames',{'frequency','magnitude'});
midTbl = table(f,mid,'VariableNames',{'frequency','magnitude'});

% Write table output
writetable(highTbl,'high.txt','Delimiter','tab');
writetable(lowTbl,'low.txt','Delimiter','tab');
writetable(midTbl,'mid.txt','Delimiter','tab');

Results

I like it! It’s nice to have a second opinion. How does my mix compare to some one elses?

I know that none of the targets I’m using were created under the same circumstances, but I have used them on my last ten gigs and I’ve found them helpful. I can find something that’s bothering me or get ideas for improvements.

The most recent example was a colleague asking me if I could make the mix sound more hyped. Hyped does mean something to me, but what does it mean to them? Luckily, they sent me an example.

I measured it. I found that it was different in some specific ways. I made some changes in pursuit of a compromise. It seemed like an objective way to get more of what they wanted.

Ideas

This gave me an idea for a plugin. If we can compare a measurement against a target, the logical next step is a filter suggestion to move the measurement closer to the target. That’s what I’m doing with my eyes anyway. It would just be nice to know the exact filter gain, width, and center frequency to get there.

I was able to come up with a non-realtime function as a proof of concept. It just finds the point of greatest contrast between measurement and target and then the filter to best reduce it. Sophisticated auto-EQ algorithms probably do this is a smarter way, but this seemed to work for now.

%Find a filter
micCompare = micMagnitude - targetMagnitude; % Find the contrast between the measurement and the target.

[pks,loc] = findpeaks(micCompare,'NPeaks',1); % Find the single highest peak.
peakFrequency = w(loc); % What frequency is it at?

startF = round(peakFrequency); % Start looking at the peak.
startGain = round(pks * -1,2); % Start gain at -1dB.
startQ = 1; % Start Q at 1.
x0 = [startF,startGain,startQ]; % All starting values.
fun = @(x) paramEQmagOnly(x(1),x(2),Fs,x(3),w,targetMagnitude,micMagnitude); % Custom function to find a parametric EQ based on magnitude only.
x = fminunc(fun,x0); % Minimize the function.

Here’s an example plot showing a filter inserted at 6.7kHz.

I spent a few days trying to build a plugin prototype in MATLAB, but I didn’t get very far. There are lots of examples out there of how to easily build a plugin to modify the audio passing through it, but not many to just measure the audio.

Have you tried something like this already? What were your results?

d&b audiotechnik ArrayCalc vs SubAligner

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Unlike my previous post about the L-Acoustics preset guide, d&b guide’s its users to perform subwoofer alignment using their ArrayCalc simulation software. I have heard from more than one colleague that they stopped using their audio analyzer after they started using d&b ArrayCalc. With such claims of accuracy I was really looking forward to comparing the results from SubAligner.

Y7P + Y-SUB

At matched level with CUT engaged the center of the crossover region is at 138Hz.

Here’s a prediction at 125Hz.

The result from SubAligner is in good agreement. The minimum delay in ArrayCalc is 0.3ms. 1.35 + 0.3 = 1.7ms.

Here’s a link to this alignment in SubAligner.

J12 + J-SUB

With the sub level offset +6dB from the low-mids and CUT engaged, the center of the crossover region is at 139Hz.

And now the results from SubAligner.

Here’s a direct link to this alignment in SubAligner.

E8 + B6-SUB

At matched level with CUT engaged the center of the crossover region is at 144Hz.

And the SubAligner results.

Here’s a direct link to this alignment in SubAligner.

Have you done any subwoofer alignment with ArrayCalc and then verified it in the field? What were your results?

Know Your Audio Analyzer Averages

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After you take several measurements and average them together, what do you expect to see?

If these two measurements are averaged, what do you expect?

Is zero the average of -6dB and 6dB, or something else?

1 octave wide parametric filters at 1kHz

Here are four possible averages you may have guessed, depending on which audio analyzer you use.

tl;dr

  1. Know what kind of averaging your audio analyzer uses.
  2. Collecting more data is more important than the way it is averaged.

Here are demos from a selection of audio analyzers in alphabetical order.

Crosslite+ v2.0.0 8

Along with options for pre and post processing, Crosslite+ offers four different options.

“Arithmetic Average Complex” : Arithmetic mean in complex values.

“Quadratic Average Complex” : Quadratic average or RMS in complex values.

“Arithmetic Average Magnitude” : Arithmetic mean in real values in dB, with phase zeroed.

USER GUIDE CROSSOLITE REV 1.1

Does the magnitude average change with trace offset? Yes. It appears that trace offset in Crosslite is the same as a gain change.

Does the magnitude average change with phase offset? Yes, except for Arithmetic Average Magnitude.

In this test I averaged the response of two microphone cables with a second order APF inserted on one of them at 1kHz.

Se deseja saber a média de fontes separadas coerentes ou de uma curva polar, é bom utilizar a aritmética complexa.

Se é média para curvas de equalização, melhor a de magnitude em dB.

Escolhi os tipos que estão mais presentes na maioria dos softwares que possuem funções de média.

Francisco Monteiro

If you want to know the average of separate coherent sources or a polar curve, it’s a good idea to use complex arithmetic.

If it’s an average for equalization, better the magnitude in dB.

[For Crosslite] I chose to offer the types that are most present in most software that have averaging functions.

Francisco Monteiro

L-Acoustics M1

M1 offers a single kind of average, which appears to be a simple average with phase zeroed.

Does the magnitude average change with trace offset? No. There is no trace offset option.

Does the magnitudeaverage change with phase offset? No.

OpenSound Meter v1.0.5

Open Sound Meter offers vector and polar averaging.

Does the magnitude average change with trace offset? Yes, the results are the same for a measured gain change.

Does the magnitude average change with phase offset? Yes for vector. No for polar.

For in-space averaging I use polar method. For vector (complex) you need to have very close phase responses.

Pavel Smokotnin

REW v5.20

REW offers two options for averaging.

Vector average, which averages the currently selected traces taking into account both magnitude and phase. It can only be applied to measurements that have an impulse response.

RMS average, which calculates an rms average of the SPL values of those traces which are selected when the button is pressed. Phase is not taken into account, measurements are treated as incoherent. This does the same as the Average The Responses button. If the measurements were made at different positions (spatial averaging) it may be helpful to first use the Align SPL… feature to remove overall level differences due to different source distances.

REW Help

Does the magnitude average change with trace offset? Yes, but only after the data is permanently changed with the Add offset to data button.

Does the magnitude average change with phase offset? Yes for vector. No for RMS.

RiTA

RiTA offers a single options for averaging traces: Arithmetic Average Complex

Does the magnitude average change with trace offset? Yes.

Does the magnitude average change with phase offset? Yes.

The next version of RiTA will include three options for averaging.

Complex AVG: magnitude estimation is greatly affected when complex averaging is performed. It is useful when you are interested, in close measurements, in knowing the constructive and destructive interference of the sound system.

ABS AVG and dB AVG are intended for spatial averaging of several microphones. Abs AVG tends to give priority to good data and less to data affected by reflections. dB AVG gives equal weight to all data.

By default, RiTA 2.5 uses ABS AVG

Pepe Ferrer

SATlive

SATlive offers a three options for averaging: Create Sum Trace, Complex Add, and Weighted Average.

Does the magnitude average change with trace offset? No

Does the magnitude average change with phase offset? Yes for Complex Add. No for Sum Trace.

SATlive offers 3 different approaches for averaging different measurements.

1. Complex averaging: Will calculate the sum using the amplitude values of each trace and the phase relation between the traces. It is intended to average measurements taken at the same mic position, like Sub/Top time align or interference of different sources. (quick traces -> sum trace complex averaging).

2. Amplitude based averaging: Will calculate the sum by normalizing (center at 0 dB) each trace and afterwards adding the amplitude values only. This is helpful when you want to average traces taken at different mic locations (and in most cases, using the same source).  (quick traces -> sum trace Create Sum Trace).

3. Weighted averaging: This is a special version of 2. where you can assign a weighting factor to each trace (three configurable settings). This was inspired by the Primary/Secondary/Tertiary measurement approach, which I first heard about during my SIM II seminar. In fact, it does not make much sense to add tertiary traces to the result, but it would be possible. (Trace Manager)

Hint: There is a Valid only if all traces valid option for 1. and 2. where you can define wether just one valid result at a certain frequency will be sufficient for a valid result or all traces averaged must contain a valid value to create a valid result.

Which of the options do you recommend to your users for judgement of tonality and EQ operations?

Only option 2. and 3. will make sense here. I rarely work with averaged measurements during EQing. Normally I’d use the Primary Location trace as the base for EQ while the other traces help me to distinguish if the problem is global or just local.

Big differences between the different mic-locations (primary/secondary) indicate a problem that you should fix before applying the eq (redirecting the speaker, additional speaker, speaker with a different directivity pattern).

For overall tonality I’d go for 2 and for Eq-ing for 3

Thomas Neumann

Smaart v8.5.0.2

Smaart offers two options of averaging with the second including built-in proprietary pre-processing.

Decibel spatial averaging, sometimes called arithmetic averaging, is a simple average of decibel magnitudes at each frequency. Spatial power averaging is the average of squared linear magnitudes at each frequency with the result converted to decibels.

Unweighted dB averaging works exactly the same way both transfer function magnitude and spectrum averages. When you select Power averaging for transfer function measurements, however, Smaart automatically adjusts the overall level of all individual measurements going into the average according to their average decibel magnitudes in the range of 225 Hz to 8.8 kHz so that they are all approximately equal in level throughout that range.

Rational Acoustics Smaart v8 User Guide, Release 8.3

Does the magnitude average change with trace offset? No.

Does the magnitude average change with phase offset? No.

Our data is in dB, so we have to decide whether to average linearly or logarithmically, whether to normalize first, whether to weight by coherence (does it make sense that poor-quality data gets as much “say” in the final result as high-quality data?) and of course remembering that FFT math spits out complex data points, not simple integers.

So you can end up with a lot of approaches that are all valid from a mathematical standpoint, but the question becomes “which method gives us the most useful result?” (I could average together the number of socks in my drawer and the number of tires on my car, and even if my math was correct, it’s a meaningless answer for all practical purposes.) So at the end of the day, we want averaging that produces information that’s helpful to the user. If you have a bunch of traces and you average them, we have an expectation of what that final averaged response should look like. How well does it highlight the trends indicated by the individual traces? That’s what we’re looking for when we take an average, and so our averaging is designed with that in mind.

In terms of which to use, just like everywhere else in Smaart: if you’re not sure which setting you need, use the defaults. They’ve been carefully chosen over many years to give good results without the user having to tweak around. I actually reset the software to default configuration every time I use it, and I pretty rarely need to go in and change a bunch of things from that state. The primary advantage of power averaging would be if you’re averaging together a bunch of traces that have severe comb filtering (which hopefully doesn’t happen all that often). The math will give more weight to the peaks and less to the dips, so you end up with something that can be more representative of the overall response in that area and what your ear might tell you. But – in most circumstances, the differences between coherence-weighted dB average and power average end up being very small. If you create both types of average from the same dataset, and lay the two averages traces on top of each other, you’ll see they tend to agree very well. I think you’d have to come up with a pretty contrived situation or have pretty bad-quality measurement data to get a result where the power averaging and the dB averaging disagree.

Michael Lawrence

All together now

Here’s an overview of the different averages being discussed in high contrast. All of these are my own estimations since the math is not exposed and is in some cases proprietary.

Which one should I use?

Please follow the manufacturer guidelines and in most cases stick with the default settings.

The demos in this post average electrical measurements of symmetrical EQ filters in order to clearly expose the calculations being used. I want to be able to see clearly if the average of +6 and -6 is 0 or something else. Measurements of speakers in rooms will feature many wide peaks and narrow valleys instead of this symmetrical behavior.

As I worked through each demo I found myself wondering why I might use one average over another. Being visually inclined and looking at a graph, at first the simple magnitude average made the most sense.

(-6 + 6) / 2 = 0

M1 offers this as its only option and it is the default option in Smaart and SATlive.

Why do the other options exist?

If you had one subwoofer and I gave you another, how much would that be in decibels? You would add 0dB + 0dB to get 6dB.

If I gave you another half a sub you would have 8dB because 20 * log10(1 + 1 + 0.5) = 8.

Following the same process of linear to log conversion, we should calculate the decibel average of -6dB and 6dB like this:

20 * log10((0.5 + 2) / 2) = 1.9dB

Maybe it makes more sense now why some audio analyzers like REW, RiTA, and Open Sound Meter show an average of 1.9dB instead of 0dB.

Interestingly, Bob McCarthy finds even this form of average to be lacking since it does not take psychophysics into account.

Studying summation revealed that 20–40 dB dips are likely to stay down in only a small area, whereas 6 dB peaks may spread over a wide area. Studying perception revealed greater tonal sensitivity to wide peaks over narrow dips. Therefore we should be wary of accepting 0 dB as the best representative here. When samples agree, the averaging builds confidence. When samples differ, the average is suspect. There’s safety in numbers when math averaging is used: get a lot of samples.

McCarthy, Bob. Sound Systems: Design and Optimization: Modern Techniques and Tools for Sound System Design and Alignment (p. 453). Taylor and Francis. Kindle Edition.

In this case “0 dB” refers to the average of a 6dB peak and a -40dB valley.

My takeaway from all of this is that more measurements combined with optical averaging (looking at them all at once) is more important than the specific form of mathematical averaging you choose.

What do you think?

The Public Library of Loudspeaker Measurements

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Imagine a library of loudspeaker measurements where you could look up the frequency, phase, and impulse response of any speaker in the world.

What questions could you answer with it?

  1. Am I doing it right? Have you ever measured a speaker for the first time and realized you have no idea what you’re looking at? I have!
  2. Are my speakers phase compatible? I have to set up a system with RCF mains and QSC front-fills tomorrow. Will they play well together?
  3. Is my speaker working correctly? Do you have a maintenance routine of measuring your speakers every six months? What do you compare them to?

For the last few years I’ve been building my own little library of loudspeaker measurements to help me in my work. Maybe you’ve been doing the same. What if we joined forces to create something even better?

Transcript

This transcript was created automatically. Please let me know if you discover any errors.

A panel discussion hosted by Nathan Lively on the topic of the public library of loudspeaker measurements, I just want to mention that Nathan is the host of Sound Design Live podcast. It has surpassed six hundred ninety two thousand downloads over nine years. So these are really impressive numbers, Nathan. And yeah, we’ve we’ve sort of had your voice in our ears for lots and lots of hours up until now. And we are always willing and ready for more. So please introduce your panelists and take it away.

So this is the public library of loudspeaker measurements. What does that mean? I hope that will become apparent as we get into this. OK, so I’m Nathan, recovering sound engineer, teacher, hot chocolate enthusiast, things like that, and I’m joined by Ian Robertson, who has been over 40 years working in the professional audio industry as a touring mix, engineer system, tech, designing and optimizing sound systems and as a technical support specialist and trainer. In addition to leading seminars and educational events in the application of many of the audio product lines in a smart instructor since nineteen eighty nine become a registered smart instructor, a registered smart user since nineteen eighty nine became a registered smart instructor in twenty seventeen.

We also have Arthur Skudra. Arthur is an audio visual consultant and smart instructor with the focus on acoustics, dB programing and sound system design and commissioning. He has over 30 years experience in designing technical media systems, including acoustics, sound lighting and video systems for very large auditoriums, theaters, stadiums, contemporary churches throughout North America. And Cesar Lamschtein has twenty five plus years of experience and audio in Latin America. USA and Europe is deeply involved in the audio engineering society and today is the vice president of the US for Latin American region and all around her.

He has logged flight time experience in studio music production, live sound audio production, teaching systems and optimization, audio consulting design, installed systems, recording studio design and monitoring calibration, as well as technical document writing and translation in English, Spanish, French, Portuguese. He’s currently a formal student in the field of forensic audio. What a panel of these introductions. OK. So that question’s link went away because I hid this, but I’ll just remind you guys that as I’m going through this, if you have any questions, please go ahead and put that in the questions link.

And if Alice sees you posting questions in the chat, he’ll either remind you of the questions link or he’ll copy and paste it for you onto that page. So how many times have you seen posts like this? My guess is that you’ve seen at least one or two of them, I know I see at least one of them every day when I get online and sometimes it’s me posting stuff like that. Right. And I think they are pretty much saying the same thing, which is am I doing it right?

Is this correct? What does this mean? And I’ll share with you guys that I have the same question a lot of times when I go out into the field because I’m a freelancer, so I’m often working on a different sound system every day, different equipment. And sometimes I’m even walking in cold like I have never touched a piece of equipment before in my life. And while that is the fun part of being a sound engineer, we’re always getting to work with new stuff and deal with new challenges.

It’s also a little bit stressful because I’m expected to be the expert on this equipment that maybe I’ve never touched before. And while everything is not totally new, consoles typically work the same way. Speakers typically work the same way in terms of like doing this job. There are many features and things about them that are different. So how do I do this magic trick where I show up and do this job and pretend to be the expert and really maximize a situation that makes the client happy?

And I get paid and the show goes well and stuff like that. OK, well, that’s going to be talking about today, and I want to draw your attention before I move away from the slide, let me turn this on to a laser. I want to draw your attention to this guy here. It says, hi, please. Does anyone have smart traces for a dB sub? Just need something to compare my measurement to. So I’m not going to say anything about that yet.

Just want to draw your attention to that. So here’s a show that I worked on back in October, October 30th, I believe, went down to Texas for this political rally. At the time it was Senator Kamala Harris. And this was a challenging show because it was initially supposed to be inside and they were bringing in a minimal amount of equipment. It was going to be a small room. At the last minute. They decided they wanted to be a driving event.

People are going to drive in and just like stand around their cars. And they still had the same amount of equipment because the people who are bringing it had already left pretty much, and they didn’t have anything else they could they could bring to us. So we just had this little small group of speakers here, and then we had some fill speakers that you can’t see. And the image here. And that’s all we had. And on top of that, I had never worked with these particular speakers before.

Yes, some cases in my life. But these particular model of our No. So what happens when I get into the field and I take my first measurement and I look at it and I’m like, wait, what? What is this am I doing this right? What does any of this even mean? So. I might call up in and I’ll stay in, does this look correct or am I posted online? And that’s why I think why we see all those posts, because out of context, this doesn’t mean anything.

Right? It’s just a bunch of data. It’s just a bunch of lines on the screen. And so I start having questions, I’m like, why is there this series of dips and peaks and dips? What is the coherence look like this? Does that have anything to do with the fact that I seem to be locked on to the second peak instead of the first peak? What’s going on there? Well, I have a couple of other measurements in this orange, and I’m actually locked on to the first peak.

OK, that makes more sense to me. Now, the series of peaks and dips has changed. So now I have something to compare it to and this is already a lot better. But I still would love it if I could have some sort of picture of what this is supposed to look like before I get started. And this for me is the big difference between beginners and intermediates who are using the audio analyzers that beginners have a lot of questions of absolutes.

Right? Is this good? Is this good or bad? Is this right or wrong? And intermediates are a lot more interested in questions of comparison. How does this compare to this or that? Is it louder or quieter? How does the ripple compare? How does the frequency response compare the phase response, those kinds of questions? But how could I have done that if I just showed up in the field and this is all I had at that point, it’s kind of too late.

Right? And I’m sort of like calling in on the phone to find out what’s going on. So if you guys well, actually, let’s see a show of hands, how many of you are you can type into the chat, how many of you have ever taken a workshop with Bob McCarthy or Maryland and Dean? And into Hans. OK, cool, you guys are using the hands feature, I love it. And you can also type into the chat if you want.

Great. OK, so a few of you know what I’m talking about, if you’ve taken a workshop with either of those people or anybody else, lots of people talk about this, then you know that one of the ways that teachers talk about solving this problem is by getting up close and personal with the speaker before the room and air starts interacting with it. So what I could have should have done in the field was get up really close to the speaker with a long microphone stand or before the speaker goes up into the air, even better get up close to it.

And I think Bob McCarthy calls us getting to know the speaker. And I think we’re inventing calls this the Polaroid, something like that. The point is, if you don’t know what the response of something looks like before you measure it in the far field, you should probably compare it up close and personal. So you really see what that what it looks like before all the problems start happening. Right. Here’s the problem with that solution, I never do it, I don’t think I’ve ever done in my life, and my guess is that if you are sort of nodding your head along with me right now, then maybe you are familiar with this problem.

You get into the field and all of a sudden there’s no time. And one hundred things are going wrong and you have one hundred other challenges and fires to put out. Right. So all of a sudden things on your list start getting crossed off. I don’t have time for this. I don’t have time for that on time for this. And I don’t think I’ve ever really taken the time to do this, getting to know the speaker step, which is so important because otherwise I open this and I have no idea what’s going on.

OK, so I have found a small workaround, which is that during part of my preproduction work, I will open up the list of hardware that I have for the show tomorrow and I’ll say, OK, I’ve never worked with this speaker before. So then I go and I Google it and I find the speaker and I download the glow file. So once I have that glow file, then I can open the glow viewer, which is free, and I grab that file and I open it up and it looks something like this.

Right. But for now, just to keep it simple, I’m just interested in one speaker and then I probably want to sometimes these GELO files come with some kind of processing preset. So then I might pick something that I expect to use tomorrow maybe. This guy here and then I hit predict and I have some parameters to pick here. This is not really a workshop on using the gloves. I just want to get to our goal here, which is showing you kind of why we are building this new project.

So here you can see I have magnitude and I have phase, OK? And it’s done this production for me. And now I can export this to a table and then I can open it up in my audio analyzer. And that’s what I’ve done here. And while these don’t look exactly the same, now, I can start having a conversation and then I can look at this together and we can say, this is interesting. Like, why is this slightly different here?

And now we can talk about, OK, it’s not supposed to have this series of peaks and dips here. So let’s talk about why that’s happening and then why does this go up like that? OK. And so if the speaker is supposed to look like this with no room and when you are on access directly in front of it, then what is all of this stuff happening and what does that say about my choices for doing my alignment and doing my system tuning?

So I just wrote out the steps here in case you guys are interested and you’ve never done this before, you can come back and look at those later. So this is super helpful, right? Just having some sort of comparison. But for me, that’s not quite good enough. I’d also like to just prepare myself to actually see, are these speakers compatible? Why? Because as you guys saw in the previous slide, like I have speakers from two different manufacturers here, they’re not necessarily guaranteed to be compatible.

So how am I going to do that? Well, I loaded one of them into my audio analyzer, so maybe I can load the front fill as well. I’m sorry. Not necessarily the front fill. Just the speaker here in my kitchen. So let’s go ahead and do that, so I will go here and open up the giallo file for the captain, which I just downloaded the other day. So this is the most up to date version and it predict.

Now, this is kind of weird, right? Let’s just turn off the magnitude for a second. Just look at the thay’s. Now, I don’t know about you guys, but this is not like any kind of face to face I’ve ever seen before. So it doesn’t seem like it’s going to be that helpful for me. So what do I do now if this doesn’t help me, then what do I do? So I might call in or I might call Arthur and say, hey, do you guys have a vision of a kitchen?

Can you send it to me? And then I might have it. Luckily, I actually have it already. So let me show you what I would do once I had all of those as I might load them into this other audio analyzer called cross-line if you’ve never seen it before. No big deal. Just another audio analyzer. We’re just looking at a magnitude graph here. And I’ve got my main and speaker here in red and blue and then my sub, I’m sorry, and red and green and then my subin blue.

And what I can do now is look at the sum between all of them. And so I turn on the stump here and I see this is kind of weird, right? I’ve got summation here, but then I’ve got cancelation here and then this is weird through here. And I would sort of expect to see summation all the way through here, but I’m not quite getting it and I wonder why that is. So I can what I can mute myself here.

And let’s just take a look at the main and fill speaker here. And now I’m going to flip this graph over and just look at the face by itself. And when I do that, without even knowing anything, I can just see that these lines are not on top of each other. OK, and I think this is relevant because the peaks are on top of each other, if we look at the impulse response up here. The peaks of these impulse responses are lined up, as best as I can tell.

And so I can assume that when I do my measurements tomorrow in any other audio analyzer like this one, that. That peak is going to line up when I said that, the locator and so this might be the alignment that I get and so I can spend some time here now doing a little bit of work, preparing for tomorrow so that once I get in the field, all this stuff just goes a lot more easy. So maybe I have a preparation for what this alignment is going to be like.

Do I need some delay? Do I need a polarity inversion? Do I need something even fancier or do I need an all pass filter, some I can practice with the cue. And even if everything changes tomorrow, even if speaker positions change and even potentially speaker models, I have found that just doing this kind of a little bit of preparation beforehand makes everything go so much better tomorrow. Even with a few years of experience that I have now, getting into the field and looking at something like this is tough for me.

I want to be ready. I want to either have a picture in my mind or I want to have something to compare it to, to say what’s going to happen. OK, so I hope I have sort of like shown for you how important this is to to do this kind of work and to be prepared, because I want to know, number one, what am I looking at? And number two, are these things even compatible? Right.

So why am I talking about this? It seems that I’m leaving some holes in the story. Right. And and the holes that I feel like I’m trying to expose are where do you get this data? How do you trust it? How do you get it into your audio analyzer so that you’re ready for your event? And that is the solution that I want to present to you today. It’s this new project that I’ve been working on with my colleagues who are here presenting with me today.

It’s called Facebook. You can access it at Trece Dash book dot org. And I’ll put that into the chat for you in just a minute. I want to show you how Facebook could have helped with this problem that I’ve been going through here today. So I’m going to grab this link and I’ll put that into the chat. Because what I could have done as I could have opened Facebook and I’m going to come back to this index page in a second, but I just want to wrap up this little case study.

I could go to the search page, I could say, show me all of the QST speakers, because we don’t have many versions of every model yet, but we do have several QIC models in here already. And so now I might open up that, Katan. And not now, not only can I take a quick preview here of the magnitude and phase and some of our records even have impulse responses as well, but I can also see some things about the speaker.

How was it measured here and exactly what were the conditions that it was measured under? Because the idea here is that Alice should be able to measure this exact same speaker at home, at his warehouse, wherever, and get very similar results. And that’s actually what we’re hoping. We’re hoping that everyone here today will sign up for Facebook and do some measurements of their own speakers, because right now we only have one QST 10. But imagine if we had 10 or 20 or 30 QST Katende measurements here, and then we could look at them all in aggregate.

And then we start to have some statistical significance where we say, OK, this is really what a Katan is like. And now we all know because we can all see it because we’ve all tried it under the same conditions. OK, but practically for this case study, what you would want to do then is just download the native file because you potentially are a smart user. And so you look down here and you says, oh, the analyzer used here was smart, great.

So I can just download the native file. Otherwise you’re going to download the CSV file. Most audio analyzers can import XP or text file these days. And so that is sort of the common interchange format that we’re working with at the moment. And then that could be really helpful because then I could do all of this work, this pre production work that I showed you here and here and cross light, because I have data that I can rely on.

And now I get into the field tomorrow and I have something to compare it to and I’m ready to go. OK, so before I hand it over to Ian Robertson, the last thing I want to do is just go back to the index page here and read to you this message here, because we put it on the index page and it’s always visible there because we feel like it’s very important. OK, so if you are looking for real world reference data that you can import into your audio analyzer, you are in the right place.

This is an independent, public, nonprofit community that promotes the open exchange of loudspeaker system reference data measured by audio professionals for audio professionals together and a team effort. We can build and expand this library into a valuable source to benefit you today as well as future generations. So that’s what I have for you today. This is what we’ve been working on for the last few months. I’m excited for everybody to get involved and to start sharing your data, so I hope you’ll sign up today.

And have there been any questions so far that we need to answer?

No, not so far. So you can go ahead and introduce your panelists or continue with your presentation.

OK, so, Ian, do you want to take over the screen share or do you want me to just keep sharing? I don’t know. Maybe you want to drive.

One of the things I just kind of want to reiterate a little bit what Nathan said earlier is that a lot of this is knowing that it’s possible. One of the things that I do a fair bit of is, is training for digital consoles. And and usually what I find is, is that it’s great you start telling somebody about how to patch the console and you go through it and then you start diving into all the really detailed, intricate stuff. And you can see at a certain point, people start to get a little antsy, like, wow, there’s a lot of information here, and they start to get worried that they have to retain it.

But it’s not so much about retaining it. It’s about knowing what’s possible and knowing where to go to find the answer when you have the question right. So don’t stress about, you know, getting all the details because it’s not necessarily about that. It’s just about knowing what the possibilities are on one hand. And the other thing that Nathan mentioned, he asked for a show of hands of who took who’s taking sessions by Merrilyn or or Bob McCarthy or Madou or whatever.

A lot of us as as instructors, we cover a lot of the same material. I’ll cover some material. Arthur covers some material. But I find that for myself, when I take a class from one person or take a class from another person, it’s usually that slightly different perspective or a slightly different slant that somebody has on a particular problem or issue or whatever. And all of a sudden the light bulb goes on. It becomes clear because that person what how that person expresses it, it makes a lot of sense to me, whereas the way the other person expressed it, I might have found it more complicated.

So I’d encourage you to gather as much from all the different people that you can and, you know, carry on from there. So. One of my kind of base kind of philosophies through audio is trying to minimize the amount of variables that are at hand in any given situation. If you have one variable, there’s only one answer if you have four variables. Well, now there’s 16 different answers, 16 different places that it might be wrong. And so like an exponential growth.

So I think the trace book removes one very important variable, and that is that we have, like Nathan mentioned, we have data that comes from all these JLL files, or you can just go and you can literally just look at the spec sheet of a loudspeaker. But in in many cases, the spec sheet is either overly polished, it’s a marketing curve as opposed to a engineer’s curve, or it might be missing some data like there may not be any phase data.

Like the previous example that Nathan showed, so the one variable that I think Facebook eliminates in this whole equation is the fact that the measurements that are posted on the Facebook are done by people who are measuring speakers directly. With for the most part, I think a lot of people are going to be using smart, so the person emerges is a loud speaker and smart, I can do the same measurement. And we’ve worked on a very defined procedure for gaining a high quality measurement.

Measurements here aren’t going to be like an anechoic measurement that a manufacturer would do, which incidentally, is how they do the goldfarb’s or should do the digital files. So it’s contextual. The data and phrasebook is contextual. It it it relates directly to the measurement that I’m going to go out and make in the field, which I think is very important. So this is the first measurement that I did for a tuning session about two or three years ago.

And the question is, while this is an interesting phase response and does the speaker really look like this? Does it really have six phase wraps and sixty three hertz? Go ahead, Nathan. So. It’s a make or sound, Winry. So based on previous experience, because I’ve measured a few lying rigs, I know this is wrong, but if I if I’d never seen this, you know, is this real? Is it crazy? So go ahead ahead there.

So I could go to traceback, grab the measurement from Trace Facebook of the line and I can see what I should expect for a phase response. I should get about one hundred and eighty degrees of facelift down at sixty two hertz. Otherwise it should be relatively flat. So now we have to dig deeper. So why is my measurement so screwy? So what ended up happening is I discovered that there was a multiband compressor inserted on the output console outside of that.

That’s amazing. Is this is that what really happened? Yes.

Yeah. That is a commonly used multiband compressor and it was inserted on the main base of the output of the console. And that is the phase response of of that compressor, because for every band pass in the compressor, there’s a crossover and the crossover was actually in the signal doing. So anyway, this is the FDA’s response of that that particular plug in that was engaged on the console and just there’s a little note there that says magnitude inverted, because whenever I’m measuring a processor or a console, I always set my magnitude to invert so you can jump ahead to the next one there.

And now we can see the correlation. The cause and effect that we can see, the magnitude, its debate on the magnitude trace of the console because it’s inverted, but you can see the low frequency boost that we’re getting and you can also see all the phase groups that are coming from my measurement and they’re due to the process and what’s happening in the console. So just to we got rid of the processing in the console so you can you can hit the next one there.

And so just to verify again, trust but verify, we want to verify that once we got rid of that plug in, that we indeed didn’t have any more surprises up our sleeve, you know, from from the from the upstream signal chain. Right. So and then if you jump to the next one, this is the last result. I think this is the end result of what the wiring was after a couple of BQ changes. But you can see the phase response is basically virtually identical to the phase response that was previously submitted on the Facebook data.

So, you know, like I say, it correlates. It’s it’s it’s measurements done by users and shared. And you can hit the next one there to Nathan Lively this one. So here’s another example. And this is the end for the examples, because there is no data Facebook for this particular loudspeaker. So if I were in the field and I were to flip on my measurement and get my timing and we’ve got two and a half phaser apps in this loudspeaker, I don’t know.

Is that correct or is it not correct? Is there something else at play here or not? Well, the bottom line is, I’m not sure. I can’t put my hand on my heart 100 percent confidence and say this is the accurate. This is the right. This is the correct response with this loudspeaker. Also, there’s some there’s some wiggling up in the very, very top and there that seem a little bit extreme to me, but I’m not sure if that’s correct or not.

So without other contextual data to compare to, you know, I’m kind of I’m kind of running blind on this. So that’s to me, that’s the most fundamental purpose of of the existence of Facebook. And I’m quite excited about the project as a whole. There’s several moderators that are that are engaged myself and this to five or six of us who are moderators on the site. So when people are submitting data to the site, first of all, it takes two of two moderators to actually prove a record, which I think is a good thing.

And if you’re right, it’s fine to be aligned with a manufacturer. I’m aligned with a couple. But the other thing that’s interesting on the site is that if I submit data, I’m not allowed to moderate it. And there has to be moderators who are not aligned with that manufacturer who actually approve that data. So there’s some some really good safeguards in there. So I just want to talk a little bit about the moderator, the role of the moderator, first of all, the moderators to to review the data and take a look at it.

And there may be some some interesting things in the data that we identify as a problem in the measurement. And that’s part of our job as moderators to look at the measurements and say, OK, the problem here and this is why and to make sure that the data conforms to the measurement procedure, which is on the upload page, you can download it directly off the upload page. But the other part of moderation is that we’re a resource for people who are submitting data.

And one of the things that I think Facebook is hopefully going to. One of the end results or one of the byproducts of this Facebook is I think it potentially can be a great community and an educational platform in and of itself. So by uploading something, don’t be concerned. If you upload something and it’s not perfect and you get comment on it or it doesn’t get approved. It’s an opportunity to revise your process and get a better measurement. So hopefully the end result.

One of the byproducts and I’m hoping for with Facebook is that we end up with a whole bunch of people out there who are improving their measuring skills. Is also another happy sideline, happy couple.

So can I can I just interrupt you for a second? Because I wanted to point out that I’ve learned so much just by doing this. Like I’ve submitted things that have not been accepted because the microphone was too close, our ripple was too high or something. And then I went back and I looked at it and I did it. And so as you and I were talking about the other day and we were kind of recommending to people that you start out by measuring something that you have at home.

That way, if something goes wrong or you have to go back and redo it, you can do that in a couple of hours instead of needing to drive back to wherever you were before the parking lot or the warehouse or whatever. Cool. Well, Ian, thank you so much. Was there anything else here that I cut you off?

No, no. That was that was pretty much it for me. I’d say that the other kind of point that I wanted to make is it’s. It’s it’s not so much for in my mind, anyway, the data that’s on Facebook isn’t so much geared towards evaluating speakers. It’s not somewhere where I go to look at a bunch of different traces of speakers and decide which one is the best. It’s it’s more about verifying that my measurements are appropriate for what might be wrong with my own measurements or my own set up quickly.

Another they’ll just do quickly. Another sideline story up once ones one, a one, CS, whatever. I’ve done several different refer jobs in theaters around Canada where we go in and we start with taking one speaker and putting it on the deck and putting brand new drivers in and running it off of a single amplifier and a single processor. And then we go through every speaker with the same MAPP and processor again limiting the variables. I don’t want to try process or a speaker wire a speaker, a speaker and then go BBB, CCC.

I want to have the same amplifier and speaker and process are driving every single loudspeaker to go through all these and we make sure that every speaker works properly and then we make sure that all the wiring in the building is working properly and there’s no issues with processors. And one of the ones I tripped over several years ago, and it was only because I measured hundreds of CPUs in my life that I turned on the P.A. and I realized immediately that all the high frequency out of all the speakers was 60 feet down from a low frequency.

And it turned out that the solution or the problem was they had Bompard was actually amplifiers and they had gone into the first amplifier with Xolair and they had jumper down to the other amplifiers with a quarter inch to Xolani, and they unbalance the connection in the rack. This system had been like this for 20 years. So if I if I didn’t know that that’s what the speaker was supposed to look like, I might have done what all the other people did before me and just turned up the high frequency.

Instead of fixing the wiring problem, so having the correct data on the front end is quite valuable, and those are those are really good stories and terrifying. So thank you for putting the fear into our hearts. One of my other moderators is reminding me to remind you that the reason we have these words, actionable field data at the top left of every page of the site, because that is the main thing that we’re offering here. We’re not offering laboratory grade speaker measurements.

We’re not trying to replace those. We’re doing things for you and I. I’m making a measurement that I know that I can use in the field and I’m sharing it with you and you can also use it in the field. So actual field data data you can take action on. OK, great. Well, I want to get into Arthur Arthur segment. So, Arthur, I already introduced you. And if you would love if you would like to take over the screen share, you can.

And otherwise I’ll leave mine up for as long as you want.

So let’s talk about Facebook and its validity, usefulness and some applications here. So, you know, oftentimes I come across situations where, you know, questions arise about the data that I’m measuring and smart. And I’ve come across a lot of situations where I have to question whether something is wired up correctly or if I have a problem with the DSP settings or there’s some really odd acoustical interaction happening or an anomaly of some sort. So oftentimes I encounter myself in these kind of situations where I’m on a project site and I’m commissioning a system.

Could be a brand new system. Everything’s straight out of the box, or it could be a system that has been used many times. And, you know, we have to wonder, you know, exactly what is going on and is there any issues that I need to resolve here? Because, you know, one thing that we teach in smart classes is that the best solution to any problem is to fix it at the source. And if there is anything I drive home in my seminars, it’s always find the problem at the source and do your corrective action there.

So if there is an issue with a loudspeaker, then you need to take care of it at the loudspeaker. You can’t fix that with Nikou. And so the closer you are to the source of the problem, the more effective your solution. So anyway, I find that Facebook addresses a need that I’ve been wanting for many, many years of commissioning. So let’s talk about the usefulness of Facebook measurements. Obviously, as you seen here earlier in the seminar, it allows one to make comparisons of both magnitude and phase response to help select speakers that compliment each other.

You know, it’s not always a a. The thing that you can trust that one speaker from one manufacturer will match up with another speaker from another manufacturer, and one of the exercises I do in my class is to take a really good speaker and match it up with a really crappy speaker. It’s always fun and educational to do that because oftentimes a crappy speaker will have a really wonky crossover in the in the mid frequency’s that will inevitably cause some interaction to happen, good or bad in the frequency.

So oftentimes they’ll take the two speakers and figure out a way of shoehorning the crappy speaker to match up with a good one. Obviously, you know, if we were in a perfect world, you know, if I go to espec one speaker for the Mayne’s, I probably will speak from the same manufacturer, a complementary product for my fellow speakers and so on and so forth. So I had the luxury of being able to say what it needs to be.

But oftentimes we don’t have that option. And, you know, yeah, they may have a rocking main system, but, you know, the front filled speakers are the cheap leftovers from the previous system that they used to own. So this year allows you to make those comparisons. And as Nathan pointed out really, really nicely here, is that the ability of comparing the face Trace’s between loudspeakers as they are measured, can reveal a lot of information, especially in the overlap regions of interest that could have an impact on your your commissioning of the system.

Another usefulness of Facebook here is it’s a fantastic device to troubleshoot systems and it helps diagnose problems. Case in point, I had one system that I was commissioning and essentially it was too passive to a loudspeakers that were flown in the center cluster in a church and they were wired in parallel to one amplifier. Obviously, they were saving money and instead of buying separate amplifier channels for each loudspeaker, it just made sense in this case to share the amplifier channels for the full range loudspeaker.

So two loud speakers, full range going into one output of an amplifier. So here I am. You know, obviously I put some pink noise into the system. And, you know, the first thing I always do is just walk the coverage, just walk from left to right, listening very critically to what I’m hearing with that loudspeaker that helps me pick the optimal microphone positions to measure the system. And, you know, it’s a great tool to really evaluate what’s going on in terms of the system’s response.

But what is really revealing is what happens in the overlap region. If you’re going to overlap region between two loudspeakers in a cluster, if there are some things that are off, you will definitely hear in that overlap region. And it’s going to sound really weird. And so as I was walking across the coverage of these two loudspeakers, all of a sudden the overlap region, the high frequencies were completely gone. It was almost like I was in a cone of silence in the overlap region, whereas, you know, normally in an overlap region, you will actually hear a little bit of a rise in level because of the overlap if everything was coming together correctly.

So I really had to question what was going on. But the problem was I did not have a reference to go by on my analyzer to figure out what is going on. So I set up two microphones, one in the on access response of one speaker and one in the other. I took a measurement and smart and I noticed that there was some really weird stuff happening in the face curve in the high frequencies. So I asked the contractor that installed this.

I said, you know, there’s something really wrong here. One of the speakers is very different than the other. And, you know, if you were to just. Talk to one speaker or the other. It sounded OK, although there was some some mid range cancelation that I was hearing, kind of a whole response. But what was really telling was that when I looked at the curbs and smart, the phase curve was one hundred and eighty degrees different in the high frequencies than the other loud speaker.

And apparently I asked the contractor, I said, did you do anything to this loud speaker, to you, open it up to you. Did you do anything? Oh, yeah. We installed this initially in the church and they blew out the high frequency driver. So we had to call it the manufacturer to get a replacement driver. And, you know, these speakers are 30 feet up in the air. So it’s like it’s not going to be a trivial task to get up there and fix things.

So they replace the high frequency driver. And you know, and I know that the wiring color codes inside loud speakers doesn’t necessarily follow our standard red and black or or white and black in our standard wiring of loudspeaker systems. So they accidentally wired the high frequency driver that they replaced. Polarity reversed. And, you know, they ended up having to bring the whole scaffolding kit back to the church and set it up and fix that problem on site, while I was waiting, my clock was ticking and they had to run back to the warehouse, get their scaffold, go up there and fix the problem.

You know, it’s like, well, can’t you fix that in your cue? Well, yeah, I could put an all pass filter, but the problem is one amplifier channel is doing both speakers. So if I correct for one, the other one will have the opposite reaction. So there was no turning back here. But, you know, if I had a Facebook trace of this loud speaker, you know, measured, I would have had some real confidence in what the response of that loud speaker should be.

So I could actually show the contractor, hey, you got something wrong here. You know, for me, it was convincing the contractor that, yeah, it’s worth your time to go back to the warehouse and get your scaffolded. But I really had to put my foot down and say, look, this needs to be corrected. So just a classic example of of the ability of troubleshooting a system in diagnosing problems. Another feature, I don’t know if we touched on this yet or not, but we’ve also included in interest book the ability to measure the true output capabilities of a loudspeaker using the techniques that might sound have developed with them noise.

And so I’m hoping that we can get some real world measurement data on the true SBL capabilities. And that seems to be, you know, open to a lot of interpretation and hopefully with the procedures that we outlined in the document how to make measurements, I’m hoping that we have become a little bit more democratic in the way we measure the true Aspell output capabilities of a loudspeaker so that we have a database here that we can rely on instead of just relying on the speaker manufacturer data saying they’ll do this Max.

SBL Well, great. How do I interpret what you think, Max SBL should be? Is it, you know, 30 seconds worth of Max Aspell or is it five minutes or is it one hour? And how did you come up with those values? And hopefully with trace book, we can get a consistency in the way that data is presented so that when you look through the database here to Facebook, you can actually look at the speaker and say, oh, OK, so this one here is going to put this amount of spell out.

It may not match up with a bigger loudspeaker that has this capability. So it’s really, really handy device to measure the capability of these loud speakers. And then for reasons beyond the scope of this presentation, let’s be honest, the data that some manufacturers present is sketchy sometimes at best, if it even exists. There’s some manufacturers that my hat’s off to them. They published some really good data and I’m really happy to see that. But there are other manufacturers where this is kind of a closed book and it’s almost like pulling teeth to get any real data out of them as to what the on access frequency response to that loudspeaker is.

So, you know, it’s a mixed bag. Let’s move on here for I use up all my time here. It’s unbiased data, and we just touched on this earlier. We have third party moderators here, you know, that will moderate the data. So, you know, number one, the person submitting the data can moderate it. If a manufacturer submits it, it’s still subject to our moderation process. So you can rest assured that we’re trying to keep this as unbiased as possible.

And we also know the source. You know, every single measurement in this database has the source labeled there. So, you know, if you recognize that person’s name, should we call them up and ask them about the data that they measured? It’s an even playing field. Everything is being measured consistently. We really, really worked hard on publishing the document on how to measure these loudspeakers. And we tried to make it as easy as possible and as foolproof as possible.

Is it perfect? No, I’m sure we’ll find some errors and some modifications that we may need to make to that document is a living document and will continue to be a living document as far as we’re concerned. But we worked many months on how to refine this whole measurement process, despite all the lockdown’s and everything like that, to measure the loudspeakers. And I’ve got to say, it was very educational for me to sit in on the discussions as we refined the whole measurement process.

And there were assumptions that I made that were duly shot down. And I’m actually happy for it because I gained something from it and I learned a lot of things from it. And I was very, very happy to be a part of that process. So we’re trying to make things as consistent as possible. You know, it’s good data. You need to moderators to improve it. And it’s real world measurements, these are taken in warehouses that are not taken in an adequate shape or although we won’t refuse data that is measured under those conditions.

But I got to say, I don’t have an anechoic chamber in my back pocket here. And I would say that ninety nine percent of the people who participate don’t have that luxury. Let’s put it this way. You know, we’re trying to make this as reasonable a process as possible. So as long as you have a decent sized space to make the measurements, there is no reason why you can’t make those measurements yourself. I’ve been even debating making measurements on my driveway at my house.

Maybe I’ll have to be really careful that I don’t do it at odd hours of the night so I don’t piss off the neighbors. But there’s no reason why you can’t take those measurements, you know, at home or at the shop, you know, community. Before they got there, anechoic chamber, they were taking all the measurements of their loudspeakers off the rear dock of their factory. They had a crane that quite literally went straight out about, I think, 20 feet.

And they had a microphone stand that was attached straight to the wall, the warehouse, and they would actually fly the loudspeaker on this crane or this gantry that projected out 20 feet. And they would make the measurements that way. And I got to say, the data that I’ve seen come from community was absolutely stellar. They were probably one of the pioneers in presenting a really, really good data for their loudspeakers. So, you know, to be honest with you, I don’t think they spent more than a couple thousand dollars for this whole set up to do some really, really high level measurements.

And likewise, using the ground playing, you can do this super, super, super cheap. So and it gives us actionable data. We can use this information to make real world comparisons with reasonable uncertainty. We cannot eliminate uncertainty, but we can minimize it and keep it reasonable. Applications, troubleshooting systems, like I mentioned previously, the the problem with the cluster that I had, you know, this kind of tool would have been very, very useful in my situation.

You know, recently I had a line array that a client bought used off an auction. And so I had to come in and actually measure the entire line or a box by box. And essentially I set up a ground plain and measured each box individually. And lo and behold, I had one or two high frequency drivers that showed signs of a lot of use. So we replaced those and they have a stellar system permanently installed. Now, this is also a perfect measurement technique for rental houses to make a record of every single loudspeaker in your collection to verify the performance of your loudspeakers so that when you have a system that comes back to your warehouse, you can actually have the ability to compare each individual loudspeaker that’s coming off the loading dock and just verify that it’s it’s still within spec and still performing correctly.

So this can be a very quick verification. And, you know, if you want to post your entire inventory of loudspeakers to Facebook, you’re more than welcome to do that. And we would absolutely love that. The more data of one loudspeaker that we can get, the more confident we can get with the Trace’s. InSitu reality check, often times we can’t test loudspeakers on the site, you know, you want to do those tests before they are flown up in the air 30 or 40 feet.

So in this case, the contractor he should have done is due diligence and tested everything before removing that scaffolding out of place. So if he had done the tests on the ground, we would have found those problems very, very quickly. I do carry a very, very long mike extension pole for those cases where the speakers are already flown. So and of course, evaluating different loudspeakers for their potential application usefulness. Finally, there are some shortcomings and we’re going to be very honest with you.

This is not a perfect database. It never will be as long as there’s the human element of measuring these loudspeakers. But, you know, we can’t guarantee that everything is absolutely clean and precise. You know, you need an echo chamber for that and some very, very expensive test gear. So we’re going to admit to you that these measurements are not going to be perfect in the database. And, you know, we’ll do our best to approve data that is actually trustworthy and is clean.

And the coherent trace is going to be very key in our evaluation of whether this is really good data or not. You know, the second thing that we don’t claim to do here is measure the polar response to the loudspeaker to to measure the polar response of the loudspeakers. Not a trivial exercise. It involves getting a turntable that you set the loudspeaker on and then you measure at five degree increments or even higher resolution. You take a snapshot of the response to that loudspeaker.

And not only do you look at the horizontal angle measurements, but then you also have to tilt the loudspeaker as well. And the other dimension. So you’re getting a full 360 degrees in. Some manufacturers say, well, this is a very time consuming process because you can imagine five degree increments, three hundred and sixty degrees sphere around that loudspeaker. That’s a heck of a lot of data. So oftentimes manufacturers only look at one hundred and eight degrees spheres.

So they’re only going to do a spherical data and all that. But this this all to say that we’re not pretending to measure a loudspeaker completely. And if people complain, oh, this is not a true representation of the loudspeaker, yeah. We will admit that that is the case here. But at least you have non axis response to that loudspeaker so that you can make those measurements and make those comparisons. So that’s really what we’re after here. This is not to say that we will not include other valuable measurements.

And probably when you go through the website and you look at the data, you know, definitely in the forum raise the issue of, hey, you know, it would be really cool if we measured this kind of data and we certainly would be very open to evaluating that and enhancing the data that we collect in Facebook. So it is in flux and we definitely would consider your input on what other measurements you would find useful. Finally, it is not an exact exhaustive database of data yet.

We are just beginning and it’s only as good as it is embraced by professional sound people like you. So jump on board and start contributing to the database. We would just absolutely love your input. And even if you’re an absolute novice when it comes to measuring loudspeakers, hey, we would be more than happy to help you out in making good measurements. And, you know, don’t ever take any of our critiques or anything like that. Personally, we want to elevate the the process and help you do a better job and become a really good person to measure loudspeakers.

So anyway, that’s all I got. And sorry if I ran over time here, but hopefully you found that really beneficial.

I thought that was great and I just want to tag on to what you’re saying and say that one of the interesting side benefits of doing the work of uploading something to Facebook is that you get some very experienced people looking at your work. So if you had ever wanted to have someone like in Arthur, take a look at your work and give you feedback and and you almost get like a little bit of a private training from someone with a lot of experience, then that’s one way to do that, because all of our moderators have either been using Smart for a long time or audio analyzers in general and doing work for a long time.

So I have found that personally to be a big benefit. So we do so much of our work by ourselves out in the field. Right. That it can it can be really helpful to get someone else’s eyes on it and get some feedback. Definitely. Thank you very much, Arthur. So I guess I will take the screen share again and then until we hand it over to Caesar. So, Caesar, you here?

I am. I am. I am here.

OK. Welcome to IEM Sound Design Live. Welcome. The live sounds of.

Yeah, thank you. I’m sorry, it’s it’s it’s not it couldn’t be are worse time I had really trouble. I am having trouble with the Internet, but most of all, I have the mindset is quite blurry. I have been robbed in my studio. I came to my studio for this summit and I discovered that somebody entered it at night and took a lot of gear borrowed without any control of when he’s going to return it. So I don’t know.

That’s terrible. Yes, that’s the last thing to say, but I’ve been following at the same time that talking with the police look like an inventory of what’s missing and I’m going, gosh, I’m going to miss that, Neeve. Ten, twenty three that that for sure. OK, but OK. A lot of what I was thinking about saying has already been said. I, I just want to add I just want to add, I mean to to to to tell a little more of what’s being said and to add a little more.

Um, I remember from my times at the National Auditorium that the difference between manufacture data data and unfiled data, um, one thing that I mean, all of we who who who are aligning and processing equipment, we are not the kind of guys that that just used the system as it goes. That’s what optimization is all about. And we we fight for every dB in order to get the best performance of any system. And as such, when I received a brand new system for the auditorium that I participated in designing it, the first thing I did was to measure each and every box in order to have a picture of it, like the first day.

So I could do afterwards measuring each year or every two years and confirm that that the system was aging well and it was not ill, etc.. So this is one of of of of my my first things that I can think about that you said little about it at the beginning, sometimes comparing the absolute data data that comes from from the the the manufacturer either through anechoic or or the marketing engineered curb is not is not as useful or is very useful.

But the real data, the field data is, is, is sometimes much more useful for comparing what you have. And as such I, I would. Have loved to to have to have something like Facebook back then, like like 10 years ago or something like that, in order to, as you said, like like having the average the statistic value of of a lot of measures taken in. Again, the measures everybody has already said are unbiased, they are vetted, that this is actually data that you can be confident on and to use.

And at the same time, there’s the other part of Facebook that is very important, which is to provide, to share by sharing you you I mean, you learn a lot in the process. I mean, I, I, I was a little trying to help a little in the process you’ve been building with the other guys with been with Alex about how to measure. And we all know that this is this has been a hard work mainly for you, looking for the right amount of the right balance between complication and accuracy, how to get complicated enough or possibility of the actual measurements that can be done by people that can be repeated.

And I think you just nail it after a very long process that now becomes public and now it’s the good things to happen. Now it’s like now it’s it’s it’s about to grow and to build these data to to to see it populated by a lot of of of. Of products that that that are going to be, I think, a very useful resource to us all and learning in the process, learning either by comparing or by trying to provide data and actually getting the data on the system.

The other thing I wanted to add is related to where I am, which is, as some of you know, others don’t don’t. I am in South America. I belong to the U.S., to the Latin American region. And I think that this project is is going to be I invite everybody from the region to to join this project is going to be great for us, too, because we I mean, this this this kind of project help us to to to build filter information at the same time.

But also it gives the possibility to four months manufacturers like the ones we have in the region, like I won’t name any brand, but there are guys from Argentina making speaker the guy, guys from Brazil making speaker that are very serious, but who don’t have the budgets of the DMD or the Myerson’s or either for marketing that that is maybe good or for engineer or engineering, measuring, etc. They don’t own maybe non-liquid chamber or the possibility to I mean, they have to rent it in a university, etc.

and that it’s not that they are not serious. I mean, they are making great products that will benefit a lot if we Latin American community can populate this with good, reliable, valid measurement of products that are not maybe the ones everybody knows. So we can compare. And as Nathan said at the beginning, are those compatible with within the setup’s with other products? We don’t know. And this would be a way of of of putting actual good data about products that we don’t know a lot and we are using we were using before Bundamba every day.

We are not using them now. But hey, we are going we’re coming back sometime. So that’s more like my my two cents in this. I a lot of has been said and I really welcome the idea. I really think that this is a really great endeavor that should be that that is going to grow and it’s going to be very, very important in all of our futures. So thank you, Nathan. And that SESAR. Thank you so much.

Oh, man, I am so sorry to hear about what happened with your studio. I feel like someone is really taking a personal attack on me, screwing up our event by a man. So so, man, we’re also sorry to hear about that and thank you for showing up even in the middle of that. And I wanted to ask you, SESAR, are you impressed and happy that I’m using an audio analyzer from Latin America? That make you happy, a.

I mean, I am I am so low now that even even your hair makes me happy.

OK. OK. All right. So we’re going to get into some Q&A. And Divya asked a couple of questions in the past. And I’ve totally been ignoring and sorry about that. So I think this is actually a question for you, Arthur, because it came in during your presentation and it basically just says, what is a polarity inversion?

Well, when I was looking at the loudspeaker in that cluster situation, I was paying attention to the phase curve. So I measured one speaker and it produced a really nice even phase response. Then I looked at the other loudspeaker and yeah, it has a built in passive crossover and, you know, equidistant. The microphones were perfectly consistent at the same delay time for both microphone measurement positions. So everything was the same in terms of the measurement conditions of each mic for each speaker.

Obviously I could turn off both one speaker at a time because I didn’t have a ladder long enough to go up there and popped the connector off of one speaker and just measured them one at a time. So I was comparing the two and what I did was I just took snapshots of each loudspeaker and then overlaid them in Smart. And I looked at the face trace and that was my aha moment going, Hey, did someone switch the wiring around here?

You know, I you know, this, you know, it’s not too unheard of that a manufacturer might have screwed up something and wired up a driver. Reverse polarity. But when you look at the face trace and you see a trend where one phase trace is one hundred and eighty degrees different than the other over the range of frequencies of that particular driver, then, you know, you have a polarity reverse situation happening there. And I think that getting data from Facebook, I could overlay that within Smart and even compare that, because here I was stuck in a situation where I didn’t know which one was was correct and which was not correct.

It was really hard to judge that because I didn’t have a frame of reference of what that loudspeaker should measure correctly and that this is a couple of years ago. And really all what I had to to go by was to call up the manufacturer. And I knew one of the tech support people there. And I asked them, I said, OK, what am I looking at here? Which speaker is the right one? Which one’s the wrong one?

And we were able to deduce from the smart trace which one was the wrong one. And then I talked to the contractor and he verified that he had replaced the high frequency diaphragm. So smart is a very powerful tool. As long as you keep everything you know, you know, when you go into the delay locator, you find the delay time for each loudspeaker. Make sure both are exactly at the same time reference so that you can make the comparisons without being influenced by other factors.

So that’s the key is to measure consistently and trace book is in some respects a way of measuring consistently. So you can actually see what’s happening with that phase response. And, you know, one speaker, the phase response was absolutely smooth from about two hundred hertz all the way up to twenty. Cain’s nice, flat smooth. The other loud speaker it was you could see the phase curve and then all of a sudden it jumped one hundred and eighty degrees at the crossover point typically of where their high frequency device was.

And that’s when I knew a, there is something wrong here. So you could do the same with a low frequency driver as well. You you will see those inconsistencies occur right at the crossover region. Typically in a two way loud speaker, that crossover will be around 1000 to 2000 hertz, depending on the size of the box. Others might be lower, others might be a little higher, just depending on how the speakers built. Hopefully that helps.

Yeah, that was great. Thank you, Arthur. Go ahead.

One more thing to add, if I might, is that there’s a little bit of confusion in the industry between the term phase and polarity. And phases of shift in time polarity is an inversion of positive, a negative, and there’s no time change and polarity is just flipping the positive and negative. So we see a change of the face trace either up one hundred and eighty or down one hundred, and maybe it’s one hundred and eight degrees away from the zero.

But there’s no time component with polarity and with phase. It’s always a time component. That’s it.

Thank you. OK, Tony says, How do you measure the maximum safe SBL one speaker can produce if technical data is not given? So, Tony, I’m not sure exactly what you mean by safe, but I’m going to assume that you actually mean without distortion, because safe would mean you just go farther away so you protect your ears. But if you mean without distortion, then what we rely on at Facebook is the noise measurement procedure. And we link to that in our own documentation here.

Basically, when you get to the section about measuring maximum SBL, you’ll see that we basically say go, go look at the erm noise procedure. It hopefully it is on his way to becoming the standard for measuring maximum speed. And so we have adopted it ourselves. We don’t feel like it’s necessary to reinvent the wheel and we’re happy that that is available. So yeah, we actually don’t have we maybe only have one or no measurements with maximum speed because it’s a little bit of extra work to set that stuff up.

So we would love it if Tony, if you would do that with some of your speakers that you have and upload that data for other people to see it.

In a nutshell, what you’re looking for in measuring the Max SBL, the device is to look at the response of that loudspeaker and evaluate when it starts becoming non-linear in its response. That’s really the onset of when you’re getting to the Max Aspell capability of that loudspeaker. So am noise procedure goes into that and helps you evaluate the response. And that’s why this seemed to tie in so nicely with Facebook, is that we’re measuring the response of the loudspeaker under its ideal conditions when it’s showing an absolutely linear behavior.

And what I mean by linear behavior is that no matter whether you have 50 DPL coming out of that loudspeaker or 80 or 90, the consistency of the response to that loudspeaker, we very, very much the same. No matter what volume level you listen to it, as soon as you get to the point where it starts distorting, you’re getting into the nonlinear behavior of the loudspeaker and naturally the response will change accordingly. So that’s what you’re looking for when you’re doing Max Aspell.

Yes, it’s loud. Yes, you need to wear hearing protection, but I think it would be very, very useful to make those measurements as well.

OK, we’re going to start wrapping up here and getting ready for our next presentation. So if you have any questions, please put those into the questions link. Maybe you can put that question link into the chat again, owlish or just on mute yourself or put your hand up. Some final things that I’ll share are these questions that came in ahead of time. So you guys know when you signed up for the summit, you I asked you what is the main thing you want to learn here?

And it’s annoying that I forced you to answer that. But it’s really important for us to have a sense of of what you guys want to learn while you’re here. And I found several questions where I feel like the answer is just Facebook. So with all of these questions here, Savala says after this covid era, what will you or anybody do differently than before? One thing that I’m going to do before is always do some pre production work where I’m referencing Facebook.

Can I go and see? Did someone upload a measurement of that? Kate in. Oh, Alice did. OK, great. So I’ll download that. Thank you. And another question. How do I pick the crossover frequency in DSP for main subs with unmatched, weaker brands? How do I choose which type of CPU? So we’ve been talking about that today in an Arthur and I both spoke about like, how do we deal with some of these problems that face compatibility and and brand and model compatibility?

And again, I feel like the answer is starting with Facebook, because we can download that data, look at it before the room starts getting involved and really do our due diligence in our preproduction work. And then finally, Jeff Mayers. And then what are the best practices for maintaining phase coherency through the PEO? And again, the answer here is to Facebook. You want to take a look at that stuff before you get into the room and told that great story about measuring all these phasor apps.

And it looks like all this line is not phase compatible with anything else anymore. Well, once he had some reference, he could do some further investigation and discover that there’s something else in line that was actually causing that apparent faced problem. OK, a couple of other questions came in. Brandon says, Do you plan to make any public forum on Facebook to share in the field measurements, ask questions, et cetera, outside of the approved Trace’s for reference?

Yes, exactly. So if you go to Facebook, there’s a little I’m not sure if you can read this text depending on what device you have, but up here in the navigation bar, it says forum. And yes, so here’s the forum and you can post things. And this is where I direct everyone. If they either have a question or have something they want to share that is not necessarily fall within the parameters of Facebook. We have had lots of people make suggestions about things that we should add.

We should add in situ measurements, we should add arrays, we should add polar plots off axis measurements. There are great arguments to be made that off axis measurements are actually more important than on axis measurements. We’ve heard a lot of this stuff and we really appreciate that. And no one’s arguing that those aren’t important. But for these first steps with this new project, we have put some constraints on what we’re accepting at the beginning so that we can just see if we can get this thing going in this measurement procedure, working with on access.

So those elements, once we get that rolling and we see that the procedure is working and people are making uploads and the site’s working and people actually want this and there’s some demand for this, then we’re going to start looking at those next thing. So if you take a look at the feature request or the product roadmap, you’ll see that we are exploring and considering some of these things like arrays and off axis measurements. But until then, we would love for you to share those here in the forum.

So if you go to the forum, you can just make a new post and say, hey, this doesn’t go into Facebook, but I have this array and I just want to share it here. And then other people will be able to search that because this this whole place is searchable. So we could type in Branden’s upload or Branden’s array or whatever the the the brand is that he used. And did you want to say something and go.

Well, there’s also on on every record, there’s also the discussion and then there’s the moderation discussion. So there’s a discussion. That’s if I’m correct, Nathan is public. And then there’s also an area in that record for a moderator to have a private discussion with the person who uploaded the records so we can get into some more technical things with with you. And that, you know, if you have a discussion, if you want to talk about something that you don’t want public privately between the moderator and yourself, you can do that yourself as well.

Yeah, this has been really interesting because as soon as someone uploads something, we have some questions. And and this is where actually a lot of the learning for me happens is sort of in these these private discussions. But, yes, that’s great. So we have a discussion panel here where you can ask questions and you can say, hey, Nathan, why does this look like this? Why did you do it this way? And that’s what we really encourage that, because we want to like we want to focus on the data.

Right. We want to focus on how this thing was done and see what we can learn from it. OK, Todd says, how about adding microphone traces to the library, Nathan dropped the 414 well, it passes audio, but he didn’t drop the 414. Hey, Todd, I don’t know if you have a microphone, you’re able to talk. I’m not sure what you mean by the 414, but my son, I was given an example, like in a show or somebody drops a microphone.

Usually you just pick it up, plug it in and it works. Well, another way to trace like compare it to the original, either if you buy one new, you could put it in or you don’t have a reference. You could find somebody else’s 414 and compare it to see if it’s damaged. Yeah, that actually happened to me recently. I dropped my second microphone or it fell over on the stand and I thought that’s probably fine. Right?

And then I got to the end of the day and saw that that my two imex seventy one fifties don’t match anymore. And I brought up Smart again to see if I could find that real quickly. I may not because sometimes when you reopen it, they’re not in chronological order again.

Yeah, go ahead. Whenever I’m doing a precision microphone comparison, the source is critical. So if I measure a microphone with my speaker and you measure a microphone in a different situation with your speaker, the variable is going to be the acoustic environment and your speaker as well. I’m back to eliminating variables. If you’re going to do precision microphone comparisons has to be the same source in the same conditions at exactly the same distance. So for that reason, I don’t think it would work so well and Tracy.

Great, thanks.

Yeah, and there are also some other projects out there, like a test kitchen where we’re not exactly the same thing, but kind of similar, and I would expect that they would probably move into that before we would get into microphones. But, Todd, if you if you think that’s important, maybe put that into a feature request so we can sort of have it on the have it on the radar.

It seems to be a very cool application of it, you know. You know, we could also possibly look at measuring in your monitors as well. And you have that that might be kind of a side database because it’s not really measuring the same conditions as you would a loudspeaker. But I can see the usefulness of having some kind of a compile data of response curves. I mean, you know, it’s not that hard to measure and 758 and determine the response as long as you have a good noise generator to measure by, you know.

But, you know, if you could get a quick and dirty curve of an S m fifty eight and be able to compare it to other parts. Fifty eight. So that would be great. I know I keep a database of all my measurement mikes that I have in my collection and compare them to a platinum standard that stays in my office unless I need to make comparisons. But I can see the usefulness of it. I really can. And for musical instrument mix.

Yeah, maybe. I think the big thing that we would have to overcome is how do you take into account things like the Polder Responsive mic? It’s not that hard to do Anami Directional Mike, but once you get into a car toid or Hypercar toid, then you have the influence of the room coming in and and wreaking havoc to your measured response curves. But one thing I noticed is if I drop my earthworks microphone and the tip gets bent or damaged or something like that, one really telltale sign of something is wrong is you get an instant low pass filter around a thousand hertz, and your only choice is to send it back to the factory to get the diaphragm replaced and.

I just put a link in the chat to crinkle dotcom, I actually took some inspiration from this site when we were working on where to go. We’re working on Facebook for the first time. Somebody told me about this. And so I can’t verify any of this data. But I basically just want to verify that, yes, people are interested in this. So this guy has made a whole career here out of measuring IEMs. He’s got a lot of stuff in his database already.

So in a way, very similar to trace book. But for AMS. OK, cool. Well, I think we’re going to unless there’s any other questions, I’m probably going to hand it back to Alec and then we’ll be getting ready for our next thing.

Yeah, they don’t seem to be any more questions for you guys. Thank you so much for this presentation to all presenters. This is a great, great project and I hope we all get to participate in it and of course, upload traces for me personally, I think this is going to be reading through the documentation on how to do the measurements is going to be like a mental exercise of whether or not I have all the steps down in measuring anything.

You know, it doesn’t have to be specifically for Trisko, but it seems like a great resource to have. And again, thank you for an amazing presentation.

Yeah, yeah. That’s that’s a good point. It is great educational opportunity to just go through this document and go through the videos that we put together on the upload page. And I’m sorry to interrupt you, but I also forgot to say thank you very much, Ian Robertson, Arthur Skudra and Cesar Lamschtein for for being my guests here on the panel today. And thank you guys for listening. And if you have any questions, there is a little chat button here on the page, or you can contact me Nathan at trace-book.org or you guys know my other email addresses.