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Stop recommending Linkwitz-Riley filters

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Linkwitz-Riley filters may sum well electrically, but not necessarily acoustically when they are added to a speaker. Better to recommend them as targets to achieve a unity crossover and choose appropriate filters for each individual application.

So why do people always recommend Linkwitz-Riley filters? When we look at a measurement like this and make sense, right? And we look at the sum between them and assuming that we have the necessary polarity inversion, it’s beautiful, right? It seems like a perfect result, but we should really be careful about recommending these filters when they’re used on speakers, because the acoustic result

Will not be the electrical result. 9 times out of 10, it’ll be something slightly different. So what I want to talk about with you today is how you can get started playing with filters investigating the results 

And while you should probably never recommend one specific kind of filter, unless you are fully familiar with all of the circumstances around its implementation. So today I’m going to be doing this demo and Crosslite, which is definitely a piece of software that I recommend, but you can also do this in free software.

So I’m going to do this demo and Crosslite, but then at the end, I’m also going to show you how to do it in REW. So if you want to download REW or you already have it, you can open that up and you can do all of these steps along with me, just on a slightly different platform. Okay. So learning how to use filters. It’s definitely a good idea to start playing around with them in the electrical domain. What is the result? If we have these 2 36 dB per octave Linkwitz Riley filters, what does that look like? What does it look like?If we change the topology, the slope? What if we change the frequency between them investigating all those things in the electrical domain is really good, because then you’re just focusing on the combination of these two shapes.

The next step then is to look at what happens when we start applying these to speakers. And I’ll tell you now that what I teach my students is to start thinking about these electrical filters. Not as specifically what you want to apply, but as the target, this is the result that you might like to achieve.

If you like the shape, if you like the sound of this, if you would like to create a unity class crossover, then this is a great target to pursue. So here in Crosslite, I’ve just created these two separate channels to serve as our targets.

And so what I’m going to do now is I’m going to insert a main and sub speaker that I downloaded from Tracebook, because I wanted you to be able to use the exact same data. So let me show you how I did that. So if you go to chase book.org and you go to the search page, then you can just search for subwoofers. And that’s what I did here. It just grabbed one of the first ones. And then I downloaded the CSV file. That’s just a text file that has magnitude phase and coherence values, all of this stuff that you see in this graph here.

And then I downloaded this speaker because I measured it and I’m familiar. And you’ll notice that these are two speakers from two different brands. They are not designed to work together. And I thought that would make an interesting demo since they are quite different. Okay. So I downloaded the CSV files and then I imported them here into Crosslite. So here’s my main and sub and here they are on top of my targets. So let’s start just working on the main speaker. Okay. So I know this is what, where I want to end up. So what do I need to do? I know this is a 36 dB per octave slope, but if I add a 36 DB per octave filter, is that going to give me the result that I want? Let’s try it. So I’ll change this to Linkwitz Riley 36 dB per octave. We know we’re heading towards 80 Hertz, so I’ll insert that and.

This is not what we want. We’ve gone a little bit too far, so I could play around with the frequency here, but, we can get this part to match, but not this part to match. So maybe I like this and I could insert a filter here, but I say, you know what, let me keep playing around with this. What if I go to a less steep slope so I’ll go to 24 DB per octave. And now I play around with this and I see, wow, this gets me. Really close. This gets me part of the way there. And now I’m looking at this and I’m thinking, you know what? This is not something I want to EQ because this is just some kind of reflection. There’s a little bit of ripple here, but I am curious to see what this would look like.

Without the ripple. So I’m going to do two things. Number one, I’m going to run the noise reduction function here in Crosslite. I’ve done that already. And here’s what that measurement looks like. So a little bit less ripple here. And now this is totally improper EQ, but I am going to just apply some little filters here, just cause I want to see what this would look like without this ripple, as I mentioned.

So I’m going to put in some little filters here just to make that ripple all go away. And now I have a nice fit here. So ideally it looks like I would have only had to use one filter that Linkwitz Riley 24 DB per octave filter, maybe one other parametric filter here to achieve my target.

So as you can see, we wanted a 36 DB per octave result. But we didn’t use a 36 dB per octave filter to get there because this speaker naturally, already has some amount of roll off. You’re never going to measure any speakers that are just flat from DC to daylight, that they’re just flat all the way across and then you can add filters.

That’s not the way filters work. You’re always adding on top of something that’s already there. And so we can look at the math of that and that’s easy to figure out and we can do the numbers, but it’s also just fun to play with and just add things and see what gets you to the target as efficiently as possible.

And sounds good. All right. Let’s take a look at the sub. Let’s zoom in a little bit here. What do we need to do here? This is sometimes some of the most challenging work because here at the crossover frequency, we are already locked in. By the way, it might help to have some kind of a target here. So over here, I’m going to turn on the target today. I’m just going to use a flat target.

That’s not what I always use, and you don’t have to use the same thing, but that’s what I’m using today. So I have this target. Here’s the top of it. And then I turn on this target Delta so that I can see where the -6 dB down point is. Okay. And I see that my sub is already hitting that point. And so what do I want to do here?

What if I use something super sharp?

Imagining the shape here and I’m thinking what if I come in with a filter that’s super sharp and maybe just push this part down this way a little bit. So let’s try that first. So I put in this 48 DB per octave link what’s Riley filter, and that gets me a fit here, but now I’ll still have to work on this region and this region, and maybe that’s fine, but I’ve played with this a little bit earlier before I started this video and I came up with what I think is. A more efficient solution, which is first applying a six DB per octave first order low-pass filter.

So answer this and I play around with this a little bit and oops, I’m probably moving the wrong filter. Let’s see. I need the red guy. There it is. There we go. So with this first order filter, now I’ve got this top getting closer here. I’m getting closer to the bottom here and now I just need one filter here to make a slightly better match. And now I could keep playing around with these until I find a closer match. Okay. So let’s say that I’m happy with that.

And now let’s look at everything together. so here’s both of my measurements now with the targets. Now I’m going to mute the targets. And now I can look at the sum between these guys and I already want to have kind of a picture in my mind of what I expect. So at this -6 dB point, I expect 6 dB of summation, which should hit up here, and then I’m hoping for a nice flatline transition across here. That is the goal of the unity crossover.

So I turned on the sum, and I see that I have a big problem here. And I remember that’s right. 36 DB per octave target. I’m going to need a polarity and version. And then I take a look at the max sum here, and I know it’s a little bit difficult to see because both of these lines are black, but I’m turning. Max on and off max signifies the total potential summation, if everything was perfectly phased aligned.

So I see that I still have some work to do here in the high end. So what can I do about this? I’ll turn off the sum for a second and let’s place some markers here, just so I can see this is the crossover region that I’m going to focus on for the moment. And I take a look at the phase here and I see, oh, this is slightly problematic here.

By the way, before I go down this path, I should just point out that this some that we had, this could be good enough and I could just move on, but if I want to keep playing with this. I could try different filters. I could try a different combination of filters to see if there’s something that would achieve a better phase compatibility here.

But for the moment, I’m going to try a solution with just a second order, all pass filter here. And when I move this around, maybe I can find a solution here. A different compromise. So it seems like we have a little bit better response through the entire crossover region there. And now when we take a look at the sum and we turn the max off and on now we have a much closer result.

Okay. So again, I’m not going to say that this is the best solution. This is just what I came up with in the few minutes that I’ve been working on it with you today. If I spent another couple hours on this and tried out a bunch of different variations, I might find something that I liked better.

And then ideally I could deploy all of those as presets and then do listening tests and find the one that I actually liked the best. And doesn’t just look the best on the screen. So you saw here that both with the main and the sub the filters that I applied. Didn’t necessarily have anything to do with the target. So I wanted to end up with this 36 dB per octave result that gave me this nice flat result here through the crossover region, but I just did whatever was necessary. I was just playing around and experimenting with filters until I got to that result.

So this is why it’s probably a bad idea to ever recommend. Just one kind of filter. Don’t tell people, just use Linkwitz-Riley filters, but you could tell them head towards this kind of result, especially if people are just starting out. They’ve never heard of this kind of idea, but. Yeah, totally fine.

To just start with some kind of a template, use Linkwitz-Riley filters to experiment with them in the electrical domain. Look at the result and then play around with that and use that as a target. Okay. So I promised I would also show you how to do this in REW, in case you don’t have Crosslite at home and you want to do this work along with me.

So let’s try that. So I’ve got an REW open and before I actually import those measurements, I want to show you how you can also play around with electrical filters in REW. So you open the EQ tab and then you can just insert filters. Down here. It says crossover filters and I can use the exact same thing I was using in Crosslite here. We see the filter prediction, and now if I want to actually play with that, then I go over here and I click generate measurement from filters, and then I’ll do the same thing for my low pass filter. Generate measurement from filters. There we go. Now I can play around with these and look at the result and compare phase and all that stuff. Just like I was doing in Crosslite. All right. Let’s import those measurements. So I’ll just grab them from the finder and I’ll just drop them here and here they are. So you can see this is this, the raw data. And so now I would like to take the next steps to change the gain between them so that they line up and they look more like this, what I was doing in Crosslite and then start experimenting with filters to achieve this target.

And let me just show you how to take the first steps with that. So here over on the left, do you want to select whichever one you want to apply the filter? And then go to the EEQ window. And then from here, you’re going to choose a target. So I typically choose the speaker driver, and then, we’re going to choose our high pass filter, which is Linkwitz-Riley six. And then set this at zero or three, line it up with your measurement here. And so now we have a target here and now we can start applying filters in pursuit of that target. So I think over in Crosslite we added a fourth order filter. Let’s try that. Yeah, there we go. So that’s getting pretty close.

All of these audio analyzers and modeling and prediction software, they all look slightly different, but the data is all very similar. We see a magnitude response here. We have a target, we have a prediction, so we need some way to practice this stuff. REW is great. Crosslite is great.

There’s plenty of tools out there. So pick one of them and figure out a way that you can play with this stuff at home. And so now that I’ve shown you how to get started here in REW, maybe go back to the beginning of this video and go through step-by-step as I was doing it in Crosslite and you can do the same thing in REW.

Okay. Let me know what questions come up for you. Let me know if you have any suggestions for me and thanks for watching. 

Sub Alignment: L-Acoustics, d&b, NEXO, Coda, RCF, Funktion-One & dB Technologies

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facebook post about nexo

My most popular Facebook post from the last 4 months is this one where I simply point out that NEXO’s recommended subwoofer alignment method is the relative/absolute method. People were surprised.

If that fact surprises you then this is going to be a bombshell: L-Acoustics, d&b audiotechnik, Coda Audio, RCF, Funktion-One and dB Technologies all recommend the same sub alignment method.

I have published several articles discussing this method already, but here’s a quick refresher:

  1. Create an alignment preset for two sources that are equidistant.
  2. Modify that alignment in the field, using delay to equalize any distance offset.

With each of these manufacturer guides there are several commonalities:

  1. Alignment is important. Of course they want you to get all of the decibels that you paid for.
  2. If an audio analyzer is unavailable or inappropriate, use the relative/absolute method instead. Some people don’t own an audio analyzer, have not invested the years of practice to master its operation, or don’t have time to set it up. Some circumstances are not appropriate for an audio analyzer, like when the reflections in an arena make the data inactionable.

Interestingly, d&b would like you to start with their modeling software to find alignment, while L-Acoustics eliminates the possibility of LF alignment in their modeling software, preferring to provide you with explicit pre-alignment values in their documentation.

L-Acoustics

L-Acoustrics Prest Guide v18.0

What follows are pages and pages of pre-alignment delay values depending on which speakers you are attempting to combine. This is exactly what SubAligner does, except it is not limited to a single manufacturer.

d&b audiotechnik

TI 385 d&b Line array design 10.6

NEXO

NXAMP Manual v3.1

Consequences of a badly aligned system
Precautions
delay
nexo alignment

Coda Audio

LINUS Control v2.2.33 Time Alignment

coda audio max perforamance
Flown systems
coda audio tiray

RCF

Pre-Alignment Delays v.1.1 – Guide EN

Funktion-One

Crossover Settings

dB Technologies

VIO series

This video should start at 2:31.

What about you? Have you tried using the relative/absolute method? What were your results?

(remote) Home Theater Sound System Calibration with Smaart & Crosslite

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Back in November I had the opportunity to work on a multi-channel home theater sound system built with custom speakers. The client had their own Smaart rig so they measured the drivers and I worked on the EQ and crossover alignment within Crosslite.

What follows are clips from the meeting transcript.

We need for both of these drivers to be captured with the exact same delay locator value. Copy the delay locator value from your HF measurement. Paste it into your TF delay, and this time measure your low frequency driver again, but don’t change the delay locator.

Disable phase smoothing and magnitude smoothing and coherence blanking. Now what you’re going to do is select both of those over in the data tab and export to ASCII.

I’ve marked our crossover region here and our sums looking pretty good because I’ve done a little bit of work already. Let’s see how we’re doing in the phase. Yeah, it’s looking pretty good. So we’re adding both together, the natural row off, plus this electronic filter that I’m implementing. And so the first thing was to just check, what if we just add steeper filters instead of adding delay?

The last thing would be to now apply some EQ to make this peak go down because we did an overlap crossover instead of a unity crossover. Now I can just move this filter around a little bit and try to get a nice result there.

Yeah, I’m going to say that that’s 12dB/oct. Our goal is 24. So we need to add another 12dB/oct. So this could be perfect. Okay, let’s find our crossover region. So I’ll look for anywhere where they are 10dB apart. Delta magnitude is ten. The way you can do that in Crosslite is with these cursors. And the way you do that in Smart is you would do a trace offset. So you would offset one of these by ten and then look at this value where they still interact, where they still cross, and then you would go the other way minus ten, and then just put some kind of a marker there.

Oh, shit. It matches already with only a polarity inversion. All right, that was easy. So now we just need a little bit more EQ. Heading back to the input EQ. Okay. Should be pretty good. We can just have a look and see if we like this results. That look pretty good to you?

Let’s deploy these settings into your DSP and verify the alignment.

No delay? Shit!

How to fight power alley using end-fire arrays

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If you don’t like the power alley that results from uncoupled subwoofer arrays and you do have six or more subs and enough real estate, you can try aiming the left and right energy away from the center, improving isolation and lowering variance across the audience.

Why six or more?

The 2-element end-fire array is a one note wonder. It cancels at a single frequency in the rear. A more efficient option would be the gradient array, although there are exceptions.

from Subwoofer Array Designer

I should make it clear that the result appears to reduce the power alley only in contrast to the rest of the audience. There is still interaction in the middle, it’s just lower in level compared to on-axis with the sub arrays.

How do you design an end-fire array?

Space the elements in a line so that their operating frequency range fits nicely in between the preferred filters recommended in Subwoofer Array Designer.

What’s the least amount of cabinets that can be used effectively?

As the number of cabinets goes up, so does the range of cancellation and consistency of coverage.

  • 2 cabinets: Cancellation at 1 frequency. Could be useful for a fighting a single resonant frequency on stage. Otherwise prefer gradient array.
  • 3 cabinets: Cancellation at 2 frequencies. Better an 2. Option to convert to 3-element inverted gradient stack.
  • 4 cabinets: Cancellation at 3 frequencies. Now we’re talkin’.
  • 5 cabinets: Cancellation at 4 frequencies. Even better.
  • 6 cabinets: Cancellation at 5 frequencies. Begin to approach the point of diminishing returns.

Four elements is the most common end-fire quantity because it is effective and reasonably practical. Economizing to three units sharply reduces the randomization in the rear, leading to frequency-dependent reduction. Never end-fire with just two elements. It’s a one-note-wonder on the back side. Use the gradient in-line instead (same physical, different settings). We don’t have to stop at four, bearing in mind that the horizontal pattern narrows with quantity. Get crazy! RF antennas will end-fire 10+ deep.

McCarthy, Bob. Sound Systems: Design and Optimization: Modern Techniques and Tools for Sound System Design and Alignment (p. 321). Taylor and Francis. Kindle Edition.

A more consistent polar pattern?

I had never considered this before Tamas asked about it and I was excited about the possibility. Unfortunately, my experiments do not reveal a significant improvement using 2nd order all-pass filters over pure delay.

FrequencyOpening Angle w/DelayOpening Angle w/APF
40Hz172º160º
50Hz152º152º
63Hz134º144º
80Hz120º116º
100Hz106º100º
100 – 40Hz66º60º

One interesting side effect was the development of a MATLAB script to calculate the ideal frequency and Q parameters for each APF. Let me know if you’re interested in hearing more about that and I can update the article or send you the script.

How do I use SubAligner with end-fire arrays?

Measure the distance to the main array as you normally would, but measure the distance to the furthest subwoofer. All of the other subs in the array are aligned to it as well.

Distance measurements
SubAligner recommendation
SubAligner plot

Here’s a direct link to this alignment if you’d like to use it in SubAligner.

Resulting phase alignment in MAPP 3D
Prediction at 63Hz

Don’t we need to add 4th order filters, as suggested in Subwoofer Array Designer?

Normally, yes, but in this case there is already a native low-pass slope of 24dB/oct.

Have you tried end-fire arrays on your shows? What were your results?

How to phase align main to sub in Smaart, REW, Open Sound Meter, SATlive, and Crosslite

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The audio analyzer functions primarily as a verification tool. For this reason this article will focus on creating alignment presets, which can then be modified in the field using simple distance measurements.

To fit this into a single article I will offer an overview of a single method for each software. Although the steps with each tool might differ slightly, in general they follow this pattern:

  1. Measure each source solo.
  2. Do whatever is necessary to achieve alignment.
  3. Measure sources combined and verify summation against a target. Listen.

The Setup

  • Ground-plane.
  • Grille-to-grille (coplanar, side by side).
  • Microphone placed equidistant from each LF driver at a reasonable overall distance in order to capture actionable data and still measure the entire loudspeaker as a whole instead of a single driver or port. For subwoofers, this usually means going outside unless you have a very large room. (approx 5x measurement distance)
with permission from Merlijn van Veen

Set Levels

If you are designing an overlap crossover (+0dB), this is easy. Simply match solo measurements to the target and EQ out the summation bump at the end.

If you are designing a unity class crossover (0dB), this is surprisingly one of the most difficult steps because you want the end result to hit the target, not the individual measurements themselves. The goal is to hit the target in a single step. With most tools you’ll be working in the dark, trying to imagine where the sum is going to end up. This is why there’s a whole subroutine in my SubAligner app dedicated to finding the perfect level relationship to hit the desired target. Shout out to SATlive for being the only software that I now of that includes a perfect addition trace so you can set initial levels without worrying about the alignment right away.

For everyone else, you can start by setting levels at -6dB relative to the target and you’ll probably need to do more adjustments in the end once you see the final result.

Where is the spectral acoustic crossover?

For efficiency, it is recommended to focus on the area of interaction at greatest risk of cancellation where magnitude values are within 10dB of each other, aka the combing and transition zones.

Make the pictures match

Use delay, polarity, and filters to achieve your desired result. Either follow manufacturer specifications or get creative and come up with your own path. Maybe create presets for both and see which one your colleagues prefer in a blind listening test.

A common first step is to achieve alignment at a single starting frequency within the crossover region where you have high confidence (coherence). Find the phase offset (ΔPhase) between main and sub, then close the gap. Since the sources are equidistant, you might want to start with filters, but try both ways. Again, if you’re using a manufacturer’s preset, always start by following their guidelines.

If you’d like to use filters:

  • ΔPhase / 45º = Filter order to try. eg. 90º / 45 º = 2nd order (12dB/oct) filter (Butterworth, Bessel Normalized, and Linkwitz-Riley)
  • For all-pass filters (APF): ΔPhase / 90º = Filter order to try.
  • High-pass filters (HPF) will cause positive phase shift.
  • Low-pass filters (LPF) will cause negative phase shift.
  • It may be easier to see this in action on an unwrapped phase plot.

Applying filters is a big topic outside the scope of this article, but if your interested, please see Phase Alignment Science Academy.

If you’d like to use delay:

  • ΔPhase / 360 / Frequency * 1000 = time in milliseconds
  • If you need to wrap around the top and bottom of the phase graph then use 360 – ΔPhase. eg. If the measured phase offset between two points is 200º, but the traces are near the top and bottom of the graph and you suspect that they need to wrap around, then 360º – 200º = 160º Δphase.
  • Once you have a single frequency aligned, test out other variations at half and whole cycles away. For half cycles, add a polarity inversion. eg. If you’re aligned at 100Hz then try variations at +5ms INV, +10ms, -5ms INV, -10ms.

If you’d like to consult the Southern Oracle, you must first pass the Sphinxes’ Gate and the Magic Mirror Gate.

Verification

After you have tried several variations, choose the one who’s combined result best matches your preferred target. To break a tie, use the option with less delay or less processing overall. Listen to the result or audition multiple presets to find the one that sounds the best.

Smaart

One of the reliable things about Smaart is that the data will never change after it is stored outside from the quick compare function. This means that any change you care to make must be implemented directly in your output processor and then measured in real time.

  1. Add 10ms of delay to both outputs. The amount of delay is arbitrary, but will save you time in step 6.
  2. Measure the Main solo and capture the trace.
  3. Without changing the compensation delay, measure the Sub solo.
  4. Set the sub level to match your target trace. Capture the trace.
  5. Find the spectral crossover using trace offsets.
  6. Make the pictures match.
  7. Verify alignment and summation. Listen.
  8. Remove any extra delay left over from step 1. 

Here’s an example combining an L-Acoustics X15-HiQ with an SB118. Initial measurements reveal a 38º phase offset between them. We might first attempt to close this gap with 1.16ms of delay on the sub (38º / 360 / 91Hz * 1000), but further tests would reveal an improved alignment with a half cycle of delay and polarity inversion in the main.

Recommendations from SubAligner and the L-Acoustics Preset Guide confirm this result. If you’re a SubAligner user you can open this direct link to the alignment.

Tips: For high quality actionable data I recommend setting temporal averaging to Inf and resetting the averages with each new measurement. Consider downloading measurements from the manufacturer, Tracebook, or SubAligner in order to have some expectations to work against.

REW

The rest of the audio analyzers covered in this article offer functions to simulate output processing. In REW the EQ window allows you to experiment with different filters and then generate a new measurement that includes those filters. Then you can experiment with gain, delay, and polarity using the Alignment Tool and its auto solver options.

  1. Measure Main solo.
  2. Estimate IR Delay. Shift and Update Timing Reference.
  3. Measure Sub.
  4. Find the spectral crossover using Measurement Actions.
  5. Experiment with filters and the Alignment Tool to make the pictures match. Generate an Aligned Sum for each variation.
  6. Compare all of the Aligned Sum variations for alignment and summation. Listen.

Tips: For high quality actionable data I recommend setting the number of measurement repetitions to 8 and the length to 256k.

Open Sound Meter

  1. Measure the Main solo and capture the trace.
  2. Without changing the compensation delay, measure the Sub solo. Capture the trace.
  3. Set the sub level to match your target trace.
  4. Find the spectral crossover using gain changes.
  5. Make the pictures match. You can click on a measurement and adjust its delay and polarity while watching a sum trace calculated with File > Add math source.
  6. Verify alignment and summation. Listen.

In this image you can see me creating the sum trace on the left and then manipulating the main trace on the right to achieve better summation.

SATlive

SATlive includes some of my favorite tools for crossover alignment, which were my inspiration for getting started with SubAligner. The Live Add trace gives you a real time crystal ball preview of what the combination of main and sub will look like. The Perfect addition trace creates a target so you can see how well you are doing. The Delay-Suggestion Tool will run an auto solver and make recommendations for delay and polarity. The Area Of Interaction Tool can be used to visualize the crossover region.

  1. Measure the Main solo and capture the trace.
  2. Without changing the compensation delay, measure the Sub solo. Capture the trace.
  3. Set the sub level to match your target trace while observing the Perfect Addition trace.
  4. Find the spectral crossover using the Area Of Interaction tool.
  5. Make the pictures match with the aid of the Delay-Suggestion Tool.
  6. Verify alignment and summation by comparing the Live Add Trace against the Perfect Addition Trace. Listen.
satlive

Crosslite

Crosslite also includes auto solver functions, but instead of using a brute force iterative approach, it will attempt to align the start or peak of the impulse responses, which can be filtered to focus on the crossover region. One of my favorite tools in Crosslite is the cursor. It can be enabled to find the phase difference between measurements and even converted into time for the alignment. Crosslite also offers various filter options and can be thought of as a full DSP simulator.

  1. Capture the Main and Sub solo.
  2. User Memories > Functions > Sum > Process Method > Sum Magnitude to generate a perfect addition trace. Adjust the sub level until the Sum Magnitude matches your target trace.
  3. Find the spectral crossover either using Gain or cursors.
  4. Make the pictures match. The most efficient starting point may be found by inserting a peak filter at the input around the center of the crossover region and running the Optimize Time function. Experiment with changing the alignment to rise or peak and the filter from normal phase to phase zero. The best option here may depend on the quality of the measurement data. Always check the phase graph afterwards.
  5. Verify alignment and summation. Listen.

Next Steps

Now that you’ve created an alignment preset, it can be deployed and modified in the field using distance measurements. If you’d like to send me the speaker measurements you took along the way, I’ll add them to the SubAligner app.

How to practice at home without a PA

You can download lots of high quality data from Tracebook to practice with.

Have you tried any of these softwares? What method do you use to optimize phase alignment between main and sub?