7 Things Every Live Sound Engineer Should Know by Michelle S Pettinato

Cover Design and Layout by Grapevine Design

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7 Things Every Live Sound Engineer Should Know

Introduction

Welcome! I’m excited to be sharing the information in this eBook with you.

Mixing live music has been my passion for a long time and I’ve been fortunate to make a career out of it for nearly 30 years! During that time, I’ve met a lot of people interested in learning live sound but having no idea where to start. “What do I need to know”, they always ask?

There is just so much to learn- from a wide range of audio consoles to system processing, so many different microphones, speaker systems, wireless systems, in-ear monitors, plug-ins, and that’s just technology!

What about EQ techniques, power requirements, dealing with RF, how to get rid of feedback, how to choose the right microphones, how the whole sound system goes together…

I’ve also encountered those who have been mixing sound for live shows and events but struggling to achieve their desired results, because they lack knowledge of the core principles.

They just can’t quite get the vocals loud enough without feeding back or their mixes are lacking clarity and definition, everything is just muddy sounding or the instruments are all fighting for the same space.

Mixing live sound can present many challenges, from finding your way around an unfamiliar console to choosing which microphone to use. Then there are things like bad room acoustics, feedback, and knowing how to get good sounds.

For those who are just starting out in live sound and mixing, the vast amount of equipment can be overwhelming. It seems as soon as you master one piece of gear there is something new to learn.

There are so many different consoles, how are you ever going to learn all of them? How do you hook up the system correctly? How do you build a great sounding mix? What do these plug-ins do?

First, relax…

You don’t need to know everything straight away. Quite honestly, there will always be something more to learn. Technology and gear is constantly changing and it can be hard to keep up with. The best sound engineers are the ones who never stop learning.

It’s easy to feel like you’ll never learn it all, and while it can be difficult to know just where to start, there are some basic principles that every live sound engineer should know.

This eBook will present these 7 very important fundamentals.

Having a solid grasp of these principles will make it easier for you to:

 Understand how all parts of the sound system work together.

 Be more comfortable when working on an unfamiliar audio console.

 Be able to quickly control and eliminate feedback.

 Build better mixes and get good sounds.

 Work more efficiently.

 Have more confidence behind the console.

A little about me…

I have been working professionally as a concert sound engineer since 1992 mixing international recording artists, many of which you probably have heard of. I’ve been on tour with them all over the world, doing sound for their live performances in everything from small clubs to stadiums, and some other really strange places.

Before I set foot on my first tour bus, I had been working in live sound for several years. I worked in the A/V department of a large entertainment complex, in nightclubs, mixing local bands, and for a small sound company.

Prior to that, I had attended two technical schools to get an education in audio engineering. You see music and audio were my passion since I was a child and I was determined to make it my livelihood.

During my first few years of working in live sound, I was soaking it all in. Even though I had learned the theories and foundations of doing audio in school and even having had ample hands on experience, putting it all together in practice was another thing altogether.

When I first started mixing bands, I had no idea how to EQ the various instruments. How do I make this kick drum sound less like a cardboard box and more like a drum? How do I keep the vocal from getting lost under the guitar?

I remember the first time I ran monitors for a local band. I understood the concept of what I was doing and how all the equipment worked but lets just say my execution was off the mark!

Luckily, I had the support of some very patient colleagues who were incredibly generous with their knowledge.

Now after all these years of mixing live music I want to share my knowledge with you. If you’ve downloaded this eBook, it tells me that you are not just interested in doing live sound but you care about doing it well!

Mixing live sound isn’t hard but doing it right and doing it well can be. Almost anyone can get sound through a mixer. As a matter of fact, almost everyone and their brother has claimed that they ‘used to do sound’ at some point in their life. How well they did it is a whole other story. Hey, I’ve swung a hammer or two but I would never claim to be a carpenter.

There are some very important principles and techniques that everyone mixing live sound should understand. It can be painfully obvious when the person doing sound does not understand them. These principles and techniques lay the foundations of being able to do live sound well.

I am happy to share them with you. They have helped me be at ease no matter what console I was mixing on, even if I had never used it before. They have helped me to get great sounds and build well-balanced mixes. These techniques allowed me to pull a mix together very quickly and solve problems expeditiously. They are also crucial in dealing with feedback or avoiding it altogether.

So what are these 7 things every sound engineer should know?

1- Signal Flow- How the signal gets from the source to the PA and through the console.

2- Proper Gain Structure and Gain Staging- How to get the best signal.

3- Frequencies and EQ techniques- Carving out your sound and why you need to EQ the PA.

4- How to Choose the right Microphone- Mic Placement and proper mic technique.

5- How to use Dynamics Processors- Gates and Compressors are your friends.

6- Basic Troubleshooting- What to do when the something goes wrong.

7- Great Sound Starts at the Source- Garbage in, garbage out.

Let’s get started!

Two of the most important things to know are signal flow and proper gain structure.

1- Signal Flow

Signal flow is the path of the audio signal from its source to its output. In mixing, is how the sound gets from an instrument on stage to the audio console and what path it takes through the console before finally coming out of the speakers.

Reasons you need to understand signal flow:

 To properly connect all the various pieces of your sound system.

 To troubleshoot problems in a logical manner rather than just trying random things.

 To be able to work quickly and efficiently on any audio console (also called mixer, soundboard, or desk).

 To achieve proper gain structure and gain staging, both necessary for getting good sounds and the best performance from the sound system.

 To know how the signal gets through the audio console and how it is affected at each stage.

Let’s break these down one by one:

Proper wiring of the Sound System

Sound Systems are comprised of many different pieces of equipment, including but not limited to loudspeakers, crossovers, amplifiers, signal processors, audio consoles, microphones, DI boxes, sub snakes, splitters, etc. There is a specific path the audio signal needs to take through this equipment for it to function properly.

Knowing signal flow allows you to correctly wire all these components together.

You need to patch the inputs on the stage to the snake, the snake to the consoles, the console to the system EQ and processors, the processors to the amplifiers and finally the amplifiers to the speakers.

Along that path, you may find sub-snakes, devices inserted on channels in the console, and console outputs routed to things like monitor mixes. When you understand signal flow, you can easily visualize how all these pieces go together.

Effective Troubleshooting

When something in the signal path fails or breaks down you will need to troubleshoot the problem so you can fix it as quickly as possible.

If you are mixing a live show and suddenly the vocal drops out of the PA, what do you do first? No- the correct answer is not -‘PANIC’. You remain calm and work through the signal path in a systematic and logical order.

Is it patched directly into the console? Is there anything inserted on that channel? What is the path from the vocal mic to the console and from the channel in the console to the Stereo Mix? Knowing this signal path, you can quickly find the problem and remedy it.

Working on Unfamiliar Consoles

The vast assortment of audio consoles on the market today can be intimidating to a novice engineer. Here’s a secret- even the most veteran engineers aren’t experts on every single one.

A thorough understanding of signal flow will allow you to be more comfortable when using a console you never mixed on before.

Signal flow through the audio console follows virtually the same path no matter what console you are using. Knowing where every single button and knob is on an Avid Profile isn’t going to do you any good when you have to mix on a Yamaha CL 3 or Midas Pro 2.

If you understand signal flow you’ll be able to figure out a new console much faster.

Achieving Proper Gain

Understanding signal flow through the audio console will allow you to achieve optimal gain of your inputs and maximum headroom. This is a necessary step in getting the best quality audio with minimal distortion and or noise.

Each component that the audio signal travels through in the channel strip of the console has the potential to add noise to the signal, and what you do to the signal in one can affect the signal as it moves through its path. For example, if you are trying to compensate for lack of input gain on the vocal channel by pushing the fader too hot, you’re likely to cause feedback. The right thing to do would be set the input gain properly and run the fader at nominal.

How each component of the soundboard affects the signal

You need to know the path a signal takes through the console to achieve the results you are looking for. If you are running monitors from the front of house console, once you have your monitor mixes dialed in, any changes you make to an input’s gain will affect that input’s level in any monitor mix it’s assigned to. This could potentially cause feedback or at least some questionable looks from the musicians on stage.

This brings me to the next subject- Gain Structure. What exactly is proper gain structure and how do you achieve it?

2- Gain Structure and Gain Staging

Gain structure generally refers to setting proper input gain to achieve the best signal to noise ratio. Optimum gain is not just turning it up until it’s in the red as a lighting guy once told me. Hmmm.

Gain staging occurs at many places in the sound system- between the console, signal processing, amplifiers, inside the console itself and from the various sources coming from the stage. The level coming into each piece of gear should be the same going out and the next device in the signal path should also be seeing the same level.

This is called ‘Unity Gain’. For example; If the Output Meter on your console is showing 0dB (nominal) and the next device in the signal path is the system crossover, it should be seeing 0db at the input and the signal leaving it should also be 0db, and so on down the line.

While some devices are used specifically to increase or decrease gain if you apply unity gain first, it will allow you to operate these properly.

Proper gain staging across the system will provide you with maximum headroom and clean, clear, undistorted sound.

Optimal Input Gain

When setting input gain on a channel, you should be hitting just into the yellow on your console meters during the loudest part of the signal. Red is clipping, and on analog, it’s ok to find peak signals occasionally hitting the red. However, digital clipping sounds terrible and is something you should avoid. Without proper input gain, your signals will be weak or distorted. If they are too weak, you’ll be trying to make up gain in other places, which can lead to added noise and potential feedback. If the input gain on all or most of your channels is set too hot, it can cause the Stereo Mix to overload. To get good quality sounds you need to start with optimal input gain.

3- Frequencies and EQ techniques

Knowing frequencies is key to getting what you want out of the sound system and sculpting individual inputs. It is also essential for quickly taming feedback. It can take time to learn how to identify various frequencies instantly, but at the very least you should be able to be in the ballpark.

If the PA sounds too boomy or boxy, you need to know what frequencies to adjust to fix it. If the vocals are muddy where do you start? If 1k starts feeding back will you recognize it instantly?

The frequency range we deal with in audio is from 20Hz to 20,000Hz, which is typically what the human ear can hear.

Hertz (Hz) is the unit of measurement used to describe the frequency of waves. Sound waves are vibrations in the air that we perceive as pitch. We measure those vibrations by how many complete cycles they make per second. 1Hz equals 1 cycle/second, 20Hz equals 20 cycles per second and so on.

Once frequencies reach 1000Hz they are abbreviated with the letter K. 1000Hz would be 1k, 2500Hz would be 2.5k and so on.

The frequency spectrum is split up into smaller ranges: Subs, Lows, Low Mids, Mids, High Mids, and Highs. The boundaries between these ranges are somewhat variable. Listed below is a typical division.

Subs 20Hz- 80Hz Lows 60Hz-240Hz Low Mids 200Hz-400Hz Mids 200Hz-2.5KHz High Mids 800Hz-2KHz Highs 2.5KHz-20KHz

This is how it would look across a 31 band graphic equalizer.

EQ can be used as a corrective or creative tool but it is important to understand proper EQ techniques. In live sound, the general idea is to use subtractive EQ rather than additive. If you start boosting a lot of frequencies you can quickly find yourself running out of headroom. If the vocals are muddy, rather than boosting the highs for some clarity try cutting the low mids and see how that cleans things up.

You also can use EQ to carve out space when you have a lot of instruments competing for the same frequency range. Understanding frequencies and how they affect the sound will make it easier for you to tailor the system to your liking and get great sounding inputs.

Before you reach for the EQ, make sure to actually listen to what you are about to adjust. EQ is not always necessary but when it is, make sure you understand how to use it properly.

A few words about feedback Feedback occurs when the microphone picks up the sound of itself coming from a speaker and sends it back the same speaker, essentially creating a loop. It can also occur when a signal level is too low and you are adding excessive gain.

The trick to fighting feedback is avoiding it in the first place. Choosing the right microphone, proper mic technique and proper speaker placement are a good place to start. Understanding signal flow and proper gain are also crucial. When you know how the signal moves through the system and the audio console, you’ll avoid inadvertently creating a feedback loop by sending the signal to itself. When you achieve optimal gain, you’ll have a stronger signal to work with.

Choosing the proper microphone and careful placement of monitor speakers will reduce feedback from the monitor system. Thoroughly ringing out the vocal mics in the PA and monitors will reduce and possibly eliminate any potential feedback. If feedback does occur, you’ll need to know what frequency is feeding back in order to eliminate it promptly.

4- Microphones

Choosing the right microphone, mic placement, and proper mic technique will go a long way in making your job easier. You should know the difference between a dynamic and a condenser and why you would choose one over the other.

Most sound engineers would know that you wouldn’t choose a Neumann KM184 over a Shure B52 for the kick drum.

When choosing the right microphone for an input, consider the frequency response of the microphone.

Which one of these microphones would you put on the kick drum?

Polar/ Pick up Pattern

The microphone’s pick up pattern is also another important factor. If your lead singer spends most of the night right on top of the PA, you’ll probably want a hyper-cardioid mic. On the other hand, if your singer has terrible mic technique you may want something with a wider pattern like a cardioid mic.

If you’re mixing a theatrical production with many actors wearing headset or lavalier microphones, you’ll want to pay close attention to the pick-up patterns and choose what’s most appropriate.

Choosing microphones with high gain before feedback will help you to get vocals loud and clear with less feedback.

Microphone Placement

Where do you place the mic on a kick drum?

How do you mic a didgeridoo? Ask me, I’ve done it.

There are some commonly followed ideas in mic placement and beyond that it’s personal preference depending on what you are trying to achieve.

Close mic’ing is popular in live sound, as it helps reduce unwanted noise from other sources. Depending on where you aim the mic at a speaker in a guitar cabinet will result in either a brighter or duller sound. The position of the mic on things like cymbals will also determine whether you get more ‘sizzle’ or more ‘clang’.

Microphones can be transparent, with little effect on the original signal or they can be chosen to add some color the sound. Proper microphone choices and placement can help you avoid feedback.

5- Dynamics Processing

Gates and Compressors are two of the most commonly used dynamics processors. Gates can reduce unwanted noise helping to clean up a mix, and compressors can tame wildly fluctuating signal levels by reducing the dynamic range of the signal.

Gates are often used on drum inputs like toms, to reduce noise from cymbals. They can also help clean up noise on things like guitars that may have low-level noise from effects pedals in the signal chain.

Compressors are great for very dynamic singers. They are also handy when several people are sharing the same microphone and the volume at which they speak varies greatly.

If you are doing sound for a seminar or other talking head type of event and have several people using one microphone, a properly set compressor will take care of the volume control so you don’t have to be constantly adjusting the channel gain or riding the fader.

Compressors are also handy on things like keyboards if the patches are all over the place in volume. Insert a compressor to keep things under control.

Both are great tools when used correctly. However, when set up incorrectly they can cause problems like signal loss and audible unwanted effects like clicking from a gate that is too tight and/or noticeable pumping or breathing from a compressor.

6- Basic Troubleshooting

Every sound engineer should have basic troubleshooting skills, which brings me back to signal flow. Without a good grasp of signal flow, when things go wrong you won’t have any idea where to start and it will take much longer to solve the problem.

The worst thing you can do when a problem arises is make random, impulsive changes. In order to work through a problem quickly, you’ll need to proceed methodically and think clearly.

If you understand signal flow and basic troubleshooting, you’ll be able to solve problems much more quickly.

If one of the speaker cabinets is not producing sound but all of the others are, the problem is likely with the amplifier or cable rather than the console output.

Troubleshooting should happen in a logical fashion to be most efficient. For example, if you lose and input at FOH you’ll want to work backward through the signal path to figure out where the problem is. After confirming that you are not getting input and it’s not a problem with an insert, plug-in, or channel assignment to a group or VCA, you’ll want to check your patch.

If the monitor engineer is getting the input it’s somewhere between the snake box and you, most likely a bad snake channel. If neither of you is getting the input it’s somewhere between the source and the snake box. Start at the source and systematically work your way to the snake box.

If you are getting a ground buzz from the guitar rig, or the guitar player is getting shocked when his lips touch his vocal mic, do you know how to troubleshoot and rectify AC grounding issues?

Learn how to solder. Cables break all the time. A cable tester and basic multi-meter are useful tools and good soldering skills will allow you to make repairs.

7-Great Sound Starts at the Source

If the source of what you are amplifying with the sound system doesn’t sound good, there is not much you can do to improve it.

Vocalists, whether singing or speaking, should practice good mic technique. Instruments should be tuned and in good condition.

When working with musicians, whatever you can do to get the best quality sounds from their instruments acoustically will help you in achieving a great mix.

If the guitar player is struggling to find a good tone on his or her amp, work with them to find something pleasing. If he or she is using a lot of pedals, check the levels and tones between them.

If the drum heads are heavily worn, and not tuned properly you’ll be doing a ton of work with EQ trying to make them sound good, whereas if they were fresh heads and tuned properly they might not need much EQ at all.

If using tracks or pre-recorded music, they should be of high quality and check that the levels are balanced. Replace noisy cables on instruments.

Keyboard players can tend to play with the output volume on their keyboards between patches. Work with them to adjust the individual level of the different patches so the output signal to you stays the same.

Work with what you’ve got

When you start with great musicians, good gear, and great sounds at the source, you’ve got half the battle won.

I’ve mixed shows with incredibly talented musicians who had great sounding instruments where I barely had to do more than turn on the channels, bring up the faders, then sit back and enjoy the show!

On the other side of that, I’ve mixed shows for musicians who were talent challenged, had beat up gear, and very different ideas from me of what ‘good tone’ meant. There was no amount of EQ’ing, effects, or magic tricks that I could pull out of my hat to make them sound good but I did my best and the audience seemed to enjoy it nonetheless.

It’s much more fun mixing when you’ve got great sounds and great musicians to start with.

Some times you don’t have a choice and there’s just not much you can do about it. The upside is times like that really help you hone your mixing skills.

Putting it all together

A few of these concepts may be unknown to those who are self-taught and even for some with formal training. The importance of having a firm grasp of signal flow and gain structure cannot be stressed enough.

Learning frequencies is critical for EQ’ing properly and to get rid of feedback.

Knowing how to use dynamics like Gates and Compressors can polish a mix and help with problems like noisy inputs or controlling widely varying signal levels.

Choosing the right microphones will capture the frequency range of the instrument, keep out unwanted noise, and help prevent feedback.

Basic troubleshooting skills are essential for dealing with problems efficiently and ultimately great sound starts at the source!

This ebook is not intended to teach you these principals but to make you aware of them and their importance. If they are unfamiliar to you and you would like to know more about them, check out the course -Mixing Music Live

There are many other things I could have included in this list but if you master these 7 principles you’ll be off to a good start. These concepts will help you be more comfortable behind the mixer and create better sounding mixes. You’ll understand how the system works and how the signal travels through it. You’ll know what to do about feedback and when problems arise. All of this should give you more confidence in mixing and allow you to enjoy yourself while doing it.

Hear’s to good sound!

Michelle

About The Author:

Michelle Sabolchick Pettinato is a professional concert sound engineer. She has spent nearly 30 years touring with and mixing thousands of shows for international recording artists including Melissa Etheridge, Goo Goo Dolls, Gwen Stefani, Kesha, Mr. Big, Styx, Adam Lambert and more.

Michelle has been a guest speaker and featured panelist at industry conferences and universities. She has written numerous articles about live sound, mixing, and life on the road and has mentored audio students and young professionals.

To learn more about Michelle, check out Mixing Music Live