Analysis: How to Tune a PA System for Live Sound

By Nathan Lively

One of the most popular articles on sound system EQ is How to Tune a PA System for Live Sound by Brad Pack. In this article I will compare and contrast it against my own methods.

Things I do the same

Start by testing the system with a few high-quality tracks that you know really well.

Yes! Listen first. The first step on my sound system tuning checklist is always Console Check (aka output verification).

Walk around and see what it sounds like up front, way in the back and over at the bar.

Yes, but be careful here. Your echoic memory is only about 20 seconds, and that’s in absence of interference. In other words, don’t expect to accurately compare the orchestra to the balcony.

It’s important to periodically bypass the GEQ and see what it sounded like before you made any changes. It’s really easy to make a mix sound worse by over-correcting, and you’ll never know if you don’t A/B (compare) your settings against the original.

Yes! My biggest takeaway from my interview with Jamie Anderson is to always incorporate strategic stop and check points to listen and make sure you are going in the right direction.

Things I do differently

The key to a good sounding show is a good sounding room, but if you don’t have one of those, you can try to fix a not-so-good sounding room by using a graphic EQ to “tune” the PA system.

While it is true that a good sounding room starts with the architecture, there are two problems with this sentence. First, you can’t fix a room with EQ. That requires a sledge hammer. What you treat with EQ are speaker-to-speaker and speaker-to-room interactions.

Second, the graphic EQ is the wrong tool for the job. The logarithmically spaced fixed frequency and bandwidth filters of the graphic EQ will never be able to create the shapes necessary to treat the frequency response created by the interactions just mentioned.

When using a graphic equalizer, try to think of each band as having a “Q” value of 100 — they’re super-narrow notches.

I used to think the exact same thing, that a GEQ was this super precise instrument. Then, I measured one. The truth is that if your GEQ has a filter bandwidth of ⅓ octave, then its Q is 4.31, not 100. There will be varying degrees of overlap between filters depending on the design.

With all of the mics “live”, slowly turn up the gain on each vocal mic and identify the frequencies that feedback
Find the band for that frequency (or the closest one to it) on the systems graphic equalizer, and slowly lower the fader until the feedback stops.

First, this won’t work with a GEQ because you’ll never be able to select the correct frequency. Does your GEQ have a filter at 839.2Hz? I don’t think so. Instead, you’ll end up damaging the frequency response of your speaker and reducing the system’s gain-before-feedback.

Second, this method will only work if the vocal mics you are using along with the speakers remain in the exact same position through soundcheck and show. A 9kHz sound wave is only 1.5 inches long. Moving the mic 0.75 inches is enough to alter the path length by 180º from a nearby surface and cause a 6dB peak where you previously had a valley.

Instead, I like to insert filters to reduce feedback on microphone groups with a parametric EQ. I send all of my vocal microphones to a vocal group. I follow the steps that Pack recommends, but instead of leaving the filters inserted, I bypass them until soundcheck. Then, during soundcheck, if I can’t get enough gain before feedback, I enable the necessary filters.

To quickly and easily find the most offensive frequencies, use a stagehand or mic stand to point the mic directly at its respective stage monitor.

Take a look at a microphone’s polar pattern. It is not uniform from back to front. Don’t expect to get the same results measuring from the back as you do from the front.

For more on my methods for dealing with microphone feedback see 6 Smart, Proven Methods To Control Feedback Onstage (Without EQ).

Essential Live Sound Training with Scott Adamson [REVIEW]

By Nathan Lively

Takeaway: This is a great overview of almost every major tool and concept you will run into in live audio. Don’t expect to walk away ready to take Scott Adamson’s job mixing for Passion Pit, but if you didn’t go to school for audio or just want a refresher, I whole heartedly recommend this course. At $29/month for over 100 video lessons, it’s a steal. Take a look at the curriculum and sample lessons here.

I was excited to get into Adamson’s new course. I had already heard from one of my student’s that it was worthwhile, especially around using effects. I was also nervous that Adamson was going to make the same mistake I see other books make, which is to talk about lots of concepts in general terms, but never show their specific application with context.

For example, Adamson gives a great overview of FX routing, but what I really want to know is how he handles his FX returns when he works with Passion Pit, Haim, Matt Kim, St. Vincent, and Sleater-Kinney. I know he has lots of great insight and experiences to share because I have interviewed him on Sound Design Live and I visited him when he came through Minneapolis with Haim. I got to poke around his board a bit and it was interesting to find his FX returns immediately following the inputs they are associated with. Kick 91, Kick Out, then Kick Verb. Snare Top, Snare Bottom, then Snare Verb.

Luckily, Adamson does not disappoint. There are lots of concepts discussed in general terms, but there are also plenty of specific examples, plus some additional Q&A videos and a webinar that share more experiences and stories. For example:

I tend to use 800ms decay for drums and 1.5s for vocals.

This is gold for me. Hearing what specific settings a successful FOH touring mixer uses means a lot.

Like/Dislike

Here are a few of the general things I really liked about Essential Live Sound Training:

I can jump to any lesson.
Graphics and explanations are clear.
Site is fast and easy to navigate.
The listening demos are really helpful.

I also really liked Adamson’s attitude. He is obviously someone that cares about great sound, but doesn’t obsess about the details unnecessarily. This is really good for someone like me that can get an unhealthy obsession with the details and lose sight of the overall picture.

Here area few things I thought could be better:

More field demos. I wanted Adamson to show me how he uses each lesson in the field, but I realize that with over 100 videos, this may be unrealistic.
More specific examples. I wanted Adamson to say, “Here’s what a gate does and here are the gate settings I used on the kick drum on the last show I worked on.”
Where are the mixing examples? A few times in the course, Adamson refers to mixing examples that aren’t there, yet. He plans to have these available the end of the summer, though. Yay!

Things I do differently

I automatically compare any new information with old information. Watching new training videos gives me the opportunity to reexamine old information and past experiences under new light. Below I’ll mention a few of the things Adamson said that got me thinking and if you are one of my students or are considering taking one of my courses, you should know that these are things that I do differently. I had a chance to talk about these with Adamson so I’ll include his responses in blue.

Let’s flip the phase and see what it sounds like.

You can’t flip phase. It needs a time component. What you can flip is polarity. I know that this still gets confused, though, since some console manufacturers like DiGiCo still label their polarity switch as a phase switch.

*Technically you’re right, but this is still common language, so don’t be surprised if you hear this on stage.

The speaker system is the end of the signal chain.

I wasn’t going to be picky about this one, but then it was a question in the quiz for lesson 9.2. Anyway, you know what I’m going to point out here: Sound still has to go through the air and your ear, which are part of the signal chain.

*It is the end of the electrical signal chain, which is still commonly referred to as the end of the chain.

To really get even sound coverage for a large crowd, line arrays are pretty much key.

I don’t want to get into the live array vs point source debate here (please, no hate mail), but it would be more accurate to say that line arrays (aka asymmetrical coupled point source proportional beam width array) are good at solving the problem of deep audiences with high front-to-back distance ratios with a single array instead of multiple relay or delay arrays. They are just another tool, not the only tool.

*You’re right. They are not the only tool. But I’m talking about crowds of 10,000 people. For practical purposes, you’re not going to cover that audience with point source arrays.

If your horns sound super harsh, you can EQ that in the processing.

Adamson is suggesting using the system processor to EQ the output to specific drivers. I would never do this unless I really know what I’m doing. Processing of individual drivers is the domain of the speaker manufacturer.

*I have done it, but I wouldn’t suggest that beginners do it. It’s pretty advanced and not something you want to do on someone else’s PA that you are walking into for the day.

The most important development in the last 25 years as been the line array.

Hmm, Harry Olson published Acoustical Engineering in 1957 and L-Acoustics’ came out with the first commercial line array V-DOSC in 1992 so…sure.

*I was talking more about their common implementation. You didn’t see V-DOSC out on shows until the mid-90s.

If you still need [stage monitors] to be loud, the other option is EQ.

What about microphone choice/placement and and speaker choice/placement? The battle for GBF (gain before feedback) is not won at any single point in the signal chain. In live sound, the sound quality off-axis is just as important as on-axis. I also wouldn’t use a GEQ (graphic EQ) to fight feedback unless I absolutely had to. I can never find the frequency that you actually need. I always have to choose one lower or higher.

*I talk about this in the polar patterns section [Lesson 2.4]. Also, you can’t guarantee that a stage monitor will stay exactly where you put it, so you can’t rely on that entirely. In practice, the GEQ is still the first thing people go to. Most people are working with very limited time and resources so they won’t have the opportunity to change the mic or speaker. In an ideal world, you wouldn’t need a GEQ, but in practice, it’s GEQ first.

Personally, I use an aux send to do this.

I avoid using subs on an aux, but when I do, I use a group instead. The problem is that if you are sending different content to the sub channel than you are sending to the main channel, then those are no longer coherent sources, they are separate, and our measurement system doesn’t know what to do with them. This can be a problem when during measurements during soundcheck or the show. So when I have the option, I’ll choose simplicity and objectivity.

*If it doesn’t sound right to me, I need to make a change. I have found that changing the sub level, EQ, and mix is key. The way I mix (and many other people mix) is with a separate mix going to the subs. The only way to do that is with subs on an aux. At minimum I advise some kind of separate send out of the console for more control, which is why I discuss using a matrix. The most important thing is to understand that the option exists.

Looking forward

Adamson helps us dip our toes into many topics in this course that raise many questions. For example:

If the amps overload the circuit they are plugged into, the circuit will trip and you will lose all the sound in your PA.

What? That’s terrifying! How do I know if I have enough power?

It’s great to know that I still have lots to learn about live audio and there is a big opportunity here for Adamson to answer many of these questions in future courses and updates, which I look forward to.

Check out Essential Live Sound Training here.

Review of Live Sound Basics

By Nathan Lively

Key Takeaways

Live Sound Basics covers important fundamentals normally taught in the first year of a university program.
Instant Feedback-Killer Battle Plan will get you started on the right foot with thinking about stage layout for better gain before feedback.
Check out the Great Church Sound mobile app for a free soundcheck checklist.

Live Sound Basics comes with three packages: Live Sound Basics, Live Sound Survival, and Soundcheck Checklist and EQ Chart. I have already reviewed Live Sound Survival in another article so I will be focusing on the remaining two packages.

Live Sound Basics

This is a collaboration between Björgvin Benediktsson from Audio Issues and James Wasem from Great Church Sound: a guide for the volunteer.

Video 1 – 42 minutes

Video one starts with a nice overview of system components and interconnections. The slides are clean and easy to read. If you are brand new to live sound, this is perfect. It covers a lot of the stuff I paid $36,000 to learn in college.

Wasem suggests downloading the Great Live Sound mobile app, but all I could find was the Great Church Sound mobile app, which includes the Sound Check Checklist. I really like checklists and this one is no exception. Although I don’t see myself actually having the patience to use it on a live event, it is a good overview and could be used for planning purposes.

I was happy to hear Wasem advise against using ground lift AC adapters. 👍🏼

The pace was a bit slow for me. Luckily, that was easy to fix that with the playback speed in VLC.

Things I do differently:

I wouldn’t say that the cold leg of a balanced cable gets “cancelled out.” I would say that the hot and cold leg get summed while what’s common to both of them gets cancelled.
I wouldn’t include an electric guitar under line level signals unless it has active pickups. Line level devices have active electronics with nominal level in the 1V range. I would consider the guitar to be in the microphone level or instrument level category.
I don’t recommend being bashful with channel EQ, especially for beginners. Wasem suggests start with a small cut and sweeping the frequency to find what sounds best. I would recommend starting with a big cut or a big boost so you can really hear what you are doing, then scaling back once you have identified the frequency.
Wasem suggests starting with 2:1 compression ratio for vocals and 4:1 for bass, but I would use the opposite settings. Our ears are more sensitive to level changes below 1kHz, which why I start with a lower ratio for bass guitar. Vocals are one of the most dynamic instruments, so I need the most help controlling their range.

Video 2 – 20 minutes

The slides are clean and easy to read and there are some nice designs showing how speakers interact with a room and each other. This video is great at raising a lot of important questions. I wish it had a part 2 to answer them.

Things I do differently:

I don’t say phase button. I say polarity inversion.
I don’t attribute low frequency cancellations in small rooms to a lack of space for the wave to develop.

Great Live Sound – EQ Chart

This chart is nicely laid out and what I learned from it is that the highest fundamental frequency of any instrument represented is 3kHz, which means that everything I hear above 3kHz is a harmonic. Neat!

Instant Feedback-Killer Battle Plan

I was really excited about this one because I hate microphone feedback and Wasem kicks it off right by talking about speaker placement. When most people think of fighting feedback, they think of EQ, but you can’t solve acoustical problems with electrical solutions. Speaker placement and aim is our first line of defense.

Wasem makes a very important point about training yourself to identify feedback frequencies that I only learned recently.

Feedback is often a lower frequency than you might suspect.

I love the microphone 3D pickup pattern illustrations. Looking at 2D designs only gives you part of the story. I learned that you should maintain a 45º angle in the vertical plane between a super cardioid microphone like a Shure Beta 87a and the stage monitor because the mic is more sensitive in the rear than at 45º. You can see the illustrations in this article by John Mills on Pro Sound Web.

I would love to see more practical examples of the theory that Wassem teaches. He obviously has a lot of experience and could share a number of stage layouts and room designs that have worked for him in the field.

The Sound Tech’s Guide to Soldering

This is a great guide and the illustrations are helpful. If I were to change anything it would be to talk about how to know which wire connects and to make it clear in the title that this is a guide to soldering XLR connectors.

Great Live Soundcheck Checklist

This is a duplicate of the checklist offered in the Great Church Sound mobile app, but it’s nice to see it all laid out.

Put guitar amps on a stand that is angled up at the guitarist.

Yes!! 💯 If I had it my way, every guitar amp would be placed at head height at a distance of no more than 2 feet from the guitarist’s ear. Instead, they often end up on the floor, blasting the front row of the audience.

Things I do differently:

I almost never pin the stage before the band arrives unless they have set it up ahead of time or we are so short on time that there will be no time for sound check anyway. Everything is going to move once the band hits the stage and it’s super annoying if the stage is already cluttered with stands and cables. There’s only so much chaos one man can handle.

I don’t start my sound check with the drummer. If I know the band and they are experienced playing on stage I will have them play all together, otherwise I will start with the vocals. The vocals have the greatest needs from us in terms of amplification and special treatment and they are also the main instrument whose quality the audience will notice. In small rooms, you may discover that the maximum GBF of the vocals is so low that amplifying anything else is unnecessary, saving yourself a lot of time.

Best Free and Paid Online Training Webinars, Courses, and Certifications for Live Sound Engineers

By Nathan Lively

This is a list of the best free and paid training for live sound engineers online today. I included all webinars, courses, and certifications I could find that required a deep time commitment from the student and excluded shorter demos and casual videos.

Did I miss something important? Comment below and let me know.

Free

Audinate – Dante certification.

Digico – SD9 training.

Get Started with Sound System Tuning – Everything you need to know to take your first measurements with an audio analyzer (like Smaart or SATlive) using tools you already own.

Harman – Introduction to Audio System Design, Audio System Design for AV Professionals, BSS Audio Signal Processors, Crown Amplifiers, DBX Signal Processors, JBL Loudspeakers, Soundcraft Mixers.

Martin Audio – Free webinar trainings on their system optimization software, control software, and speaker deployment.

Meyer Sound – The webinars section has disappeared from their site, but I dug these up on Vimeo. Here are their videos on MAPP XT.

QSC – Q-SYS Level 1.

Shure – Ethernet Networking for Audio, Wired Microphones 101, Microflex Wireless Training, Wireless Workbench 6 Video Tutorials, Advanced Techniques for RF Coordination, Microphone Techniques for Theatrical Productions.

Sound Design Live – Intro to Sound System Tuning, How To Make Money as a Sound Engineer.

SoundGym – A curated collection of YouTube videos including Live Sound Basics and Worship Sound Tools.

Waves – LV1 Mixer Training, Start Mixing with Plugins, SoundGrid Certification.

Yamaha – Training on their CL, QL, and TF consoles.

Paid

Association of Sound Designers – Acoustics & System Design, Vocal reinforcement & Radio Mics, Computer and Audio Networking.

Essential Live Sound Training – This is a great overview of almost every major tool and concept you will run into in live audio. Don’t expect to walk away ready to take Scott Adamson’s job mixing for Passion Pit, but if you didn’t go to school for audio or just want a refresher, I wholeheartedly recommend this course. At $29/month for over 100 video lessons, it’s a steal.

Pro Audio Workshop: Seeing Sound – Insider secrets to quickly and effectively maximize sound system tuning in any room.

SoulSound – Monitors from FOH, Mixing FOH, Stagecraft, How to Set Up A Small Business

SynAudCon – How Sound Systems Work, Principles of Audio, Transformer-Distributed Loudspeaker Systems, Digital Signal Processing, Audio Applications, Sound Reinforcement for Designers.

My Results from 30 Days of Ear Training

By Nathan Lively

Hypothesis: Through 10 minute sessions of daily ear training I will increase the speed and accuracy of my pitch detection and EQ application.

Why: I’m sick of guessing and sweeping with the parametric EQ. I want to nail it every time. I don’t want to fear microphone feedback anymore. Ringing out stage monitors is a waste of time. I want to quickly remove any feedback as it occurs.

Results: After 30 days I made a 13% increase in my EQ ability and tripled the speed and accuracy of my pitch detection.

When it comes to listening abilities, I have always had a growth mindset. I don’t think I’ll ever have golden ears, but I do believe that I can train my ability up to a useful level. This is very important for me and all live sound engineers because we need shortcuts to survive.

During my Live Mix Mastery pilot course last year, I talked to a lot of sound engineers about their biggest problems out in the field. I got a variety of different answers, but the common trend among all of them was the need for speed. Everyone I talked to was confident that they could overcome any obstacle thrown at them if only they had enough time. As a result, I put together all of the best time saving techniques I’ve learned over the years and taught them to 20 students over four weeks.

Every technique I taught has been field tested to deliver results except for two things: pitch memory for feedback detection and EQ training for faster mixing.

With Live Mix Mastery I had a great opportunity to test this with a group of professional audio engineers. Here are the steps we took:

User Ear Doctor in SoundGym to test your hearing.
Schedule 10 minutes of daily ear training in your calendar. Three minutes playing Audio Frequency Trainer and seven minutes cycling through games on SoundGym.

Logically, playing these games to improve our ear training to increase our speed in the field makes sense. But I had never really taken the time to practice with a system and measure my results.

What is pitch memory?

You have listened to your favorite song so many times that you can start singing it right now with pitch accuracy. Unless you were born with perfect pitch (yes, this exists) then you memorized those pitches through repetition. This is how the kid at guitar camp with me was able to identify almost any pitch. Songs were his reference. He had learned to play so many of them that playing any note would trigger his memory of a song and then its location on his fretboard. For me at the age of 18, this was mind-blowing.

I had my first taste of this in college when I set my wake up alarm to the song How It Feels to be Something On by Sunny Day Real Estate. One day I was walking into a piano rehearsal room, humming that song, sat down, and realized that I was singing a perfect A. By accident, I had taught myself pitch memory.

One of the first things you learn in music school is the interval relationships between notes on a scale in western music. Once you’ve got the pitch of any note, you can find the pitch of any other note through the memorized interval or by simply following a chromatic scale. The good news for musicians is that there are only 12 notes. The bad news for sound engineers is that microphone feedback could potentially happen at any frequency. And I guarantee you that it will never happen at the exact frequency of one of the sliders of your graphic EQ.

The only thing that graphic EQs are really good for is ear training, which is exactly what we used them for in Live Mix Mastery. Why did we use 1/3 octave spaced frequencies instead of 1/12 octave, which would relate more to our musical experience up until now? Three reasons:

I didn’t think of it at the time.
Audio Frequency Trainer was the best game I could find.
Audio engineers are more familiar with the whole numbers seen on a graphic EQ. It’s a lot easier to work with 1K, 1.25K, and 1.6K than it is to work with 987.77, 1046.5, and 1174.66.

Audio Frequency Trainer will allow you to set a minimum and maximum test frequency, which is why we visited the Ear Doctor first. There are four levels that increase in difficulty by adding more frequencies to identify. I quickly moved out of Beginner, spent about two week on Intermediate, but never graduated from Pro. That shit is hard!

A technique that I used here, which I found helpful, was to move quickly and get emotional. My intention was to send signals to my brain’s pleasure and pain centers that this was important stuff.

Unfortunately, what I didn’t get to do was try out some feedback detection in the field, yet. I will come back and update this article when I do.

Another important thing I learned is that pitch memory either improves or deteriorates. I stopped practicing after the course ended and while I haven’t slide all the way back down to Beginner, I also haven’t been able to maintain a perfect score on Intermediate.

The mystery of EQ

For many people, EQ is a big mystery. It’s one of the most difficult skills to train because we are always under enormous pressure. Wouldn’t we all love to have 30 minutes to listen to a kick mic while searching for the perfect frequencies to boost or cut. Those of you who have tried this have either never done so again, or moved into lighting.

EQ training at home is another thing that always made sense, logically, but I had never sat down to prove. Although none of these games we used are the same as work in the field with all of the chaos of a live room, they do provide the next best solution in terms of variety and tracking. Any time I have a few minutes I can log into SoundGym and play a game. At the moment, unfortunately, the games are not available for mobile, which is why I schedule my practice sessions for times when I know I will be home.

The great thing about this experiment that we embarked on together is that we didn’t have to worry about how to EQ. We just played the game and watched our results improve. The most enjoyable discovery for me was connecting the sounds I have known for years to specific frequencies. Previously I may have know where I needed to hear a filter, but would have had to guess and sweep up to it. The game Peak Master helped me to finally connect those sounds to frequencies. Here’s what one of my students, Sergio, said about it:

I had a big improvement detecting bothering or missing frequencies by ear.

And here’s what Martin said:

I was able to improve my skills to identify and remove distracting elements in my mix in less time. I no longer think, “Hmm, the electric guitar sounds weird somehow.” Now I can identify that the problem is in the low mids and make a dip at 300Hz, for example.

So it looks like we hit our goal in terms of increasing speed.

My big takeaway from this whole experience is to stop wondering how to EQ and improve my hearing instincts instead through ear training. Everyone knows when they hear a problem. The skill is finding it fast.

Did I prove my hypothesis?

Although my students did see improvements in the field in increased speed and accuracy of pitch detection and EQ application, I personally haven’t done enough work to give a firm Yes. That being said, I’m really happy to have discovered a method I can track instead of just hoping for golden ears.