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13 August 2012

Best Practices: Audio


So you either are a sound engineer, you know one, or you play one on TV. (if you're in the middle category, you can forward this to them)

Here is a list of "best practices" to keep in mind as you serve as a Technical Artist. I call you a Tech Artist because mixing live audio is both a science and an art. You have to think like an engineer and listen like an audiophile. You must make cuts like an accountant and create beauty like a musician. You get to mix colors with the accuracy of a hex code and the nuance of the little dude who painted "happy little trees" on TV. Godspeed to you!


The Four Main Elements

There are four main elements to how things sound:

1. The Source
(the people speaking, singing, and playing; the instruments; the recordings)

2. The Gear
(microphones, cables, mixers, amplifiers, effects processors, speakers)

3. The Operator
(your skills, personal taste, philosophy & approach, direction you received)

4. The Room
(characteristics of the walls, floors, ceilings, angles, and the laws of physics)

It's helpful to acknowledge each of these elements and take a look at each one individually when troubleshooting. They are interconnected, but the task of troubleshooting calls for us to separate them and then see how they are affecting the whole. Get to know each one. Study them. You're responsible to manage each of them for increase!


Muting Open Channels

Always mute any channel that is not currently being used. Think of an unmuted channel as adding risk. Risk of feedback, risk of phase cancellation, risk of interference, risk of buzz, risk of a bad recording, and on and on. (They even make units called "gates" to automatically mute (or close) a channel until a specified level is coming through it.) Sure, it makes the operator's job to be more closely tuned in to what's going on so that someone doesn't walk up to a dead (muted) mic, but it's a best practice. Think mute=safe. Be safe.


How much energy should be in the room?

I specifically didn't say "how loud should it be" since perceived loudness is just that: how loud you feel something is, is not an objective thing. There are many factors like mix, EQ, preference, how much sleep you got last night... Many churches use a dB (decibel) meter or SPL (sound pressure level) meter to set a standard "level." This is a bit of a "surgery with a butter knife" approach, however I still recommend it because it is at least completely objective. The disclaimer is that it can sound piercing and uncomfortable when the meter is reading 87 dB and pleasantly energetic when the meter is reading 94 dB. But agreeing to a range (with the church's leadership) can be a starting place for a conversation. The typical range for churches is between 85 and 95 dB, with the meter set to "slow response" and "C weighting."


Headphones

What are headphones for? Not for mixing. Not for EQing. I think they're best used for identifying - what is a certain player or singer doing? Always only listen with one ear, keeping the other ear for listening to what everybody else is hearing. Why can't you mix and EQ with headphones? They're in a different room with different speakers than everyone you're mixing for. They sound different. Don't do it.


Gain Structure

Starting at Unity gain matters because that means that the signal coming through as not being affected at all. You're not boosting or cutting in at all - it just comes through, which will sound the best just like it is. So make sure that the trim is set right, the faders are set right, and the master output is set right, and of course, the amplifiers should be set already. You may have to adjust the trim, but start with everything at Unity. Think of the trim (or gain) as "sensitivity" - the more sensitive a mic is, the more likely it is to cause feedback.


Microphones and Wireless

Not all mics are the same. Well, of course, but specific mics work better for specific situations. Condenser, dynamic, ribbon, piezo, then there are different pickup patterns (unidirectional, omnidirectional, cardioid, shotgun...) Sure, you can use an SM58 on your kick drum, but it wasn't designed for those frequencies. Get to know what you have and how best to use them. And there's this myth out there that wireless mics are better than wired mics. Here's the real story. To get the same quality of mic in a wireless version, you'll have to pay about 5 times more. Implication: If you buy a $200 wireless mic system instead of a $100 wired mic, you'll be getting the quality of a $40 mic, plus you'll be prone to the downside of wireless - drop outs, interference, and buying batteries. Wireless mics are great, or better said, great wireless mics are great. Never pay less than $500 for a wireless system or $100 for a wired mic. And stick with brands like Shure, Sennheiser, and Audio-Technica. Really! Consumer/Prosumer brands like Nady, Behringer, Mackie, Bose, Telex, Rolls, TOA, and Shure's PG Series are to be avoided like wilted lettuce. (OK, Dave, off the soapbox)


Even Coverage

A well designed room and system will have even coverage, but in many churches it does not sound the same in every seat in the room. It's your job to know what it sounds like everywhere and do your best to make it sound great wherever the majority of the people are. This may not be where the sound board is located. Discretely move around the room, or sit in different places the weeks you are not scheduled to get to know your room.


Sound Check

Sound check is done with the main speakers on. Get a rough mix in the house, starting with the monitors off. Then add a little bit of each person to the monitors so that they can hear themselves. Asking the band members "Can you hear yourself?" is the best question because they need to hear themselves. They just don't need to hear everything. It's just not possible. It'll make it sound muddy and unpleasant in the house. They need to realize that their primary monitoring should come from the actual mains not from the monitors. So if I ask them "Can you hear yourself?" and they say "no," first say "Okay, I need to help you with that, so what can I turn down so you can hear yourself?" This is called subtractive mixing (to hear something, first take away other things). To start setting the first monitor mix, zero everything out in that mix and then guess by putting just what you think they might need in the mix.


Input Check

How many times have you gone for rehearsal or service, only to figure out halfway through that the left channel of the keyboard isn't playing, or monitor #1 is actually monitor #2, or... Input checks make sure that none of that happens, so simply start on one end of the board and make sure that every input is labeled correctly. This is the time to set gain structures. If you do an input check every week, you shouldn't have to do too much gain structuring week to week.


Physical Arrangement

Make sure everything and everyone is in the best spot. For example, have the monitors the right place. Is this music stand blocking the monitor from the person listening to it? Is the best microphone is being used for the application? Are people spread out well/evenly? Are the cables run neatly? Are the right DI's hooked up to the right amplifiers or instruments? Is anything that's not being used put away off the platform?


Speakers

Aim the speakers toward the heads of the listener. I know that sounds obvious, but how often are monitors and guitar amps aimed at the knees? And get them close - every time you double the distance, it makes it sound about ¼ as loud. Think about that! (This is the Inverse-Square Law, and other factors might reduce the effect, but it's still a useful perspective) And how often are mains aimed at empty seats or back walls? Dan Keeney (Joyce Meyer's sound guy) talks about it in terms of light: imagine that the speakers were a flood light. Would they light the people's ears?


Checklists, Input Lists, & Cue Sheets

In the high pressure world of live audio, you need quick reference guides to help you in moments when your head is full of other stuff. What channel should I tell him to plug into? What was the frequency to get more oomph on the kick drum? Did I replace that 9V in the wireless? Who is getting up next? (and what mic needs to be ready?) There's no reason to keep all the details memorized. Having printed tools will help you make less mistakes. Turn the potential oops into oomph.


Subtractive Mixing

When thinking EQ, always "take the problem away" first [cut first] rather than adding. If something sounds "tinny," cut some of the high frequency rather than boosting the low frequency. You can mix this way as well - if you can't hear the lead vocal, turn the background vocals down rather than just turning the lead vocal up. If you can't hear the bass and drums enough, try turning down the acoustic guitar before turning the bass and drums up.


Pay Attention

Pay attention to what? The details, the energy in the room, the transitions, how things start and stop, and what instrument or groove is making the song work, what you really need to hear, what you can do with less of, what person or instrument is carrying the moment. Because it's such a common mixing mistake, ask yourself "Do I really need that much acoustic guitar in the mix right now?" and "Do I really need that much keyboard in the mix right now?" As your "producer's ear" develops, and your relationship with the band deepens, you may be able to make suggestions to the band like "Can one of you guitar players use a capo?" or "Drummer, can you focus on just laying a solid groove down to the rest of the band can build on you?" or "Keyboard player, would you consider playing with only your right hand and staying 1 or 2 octaves above middle C so that I can have you louder in the mix?" or "Do any of you singers know a harmony to that song?" (okay, stop laughing and pay attention)


Start Strong as a Technical Servant

When the worship leader comes in, they're thinking of at least 14 things...they've picked songs, arranged them, practiced them, thought of segues, thought of setups/intros, prayed, contacted musicians...and now they'll bring a moment of spiritual formation - a devotional, prayer, or sharing time, then they'll rehearse the band which will include making sure they can hear what they need to hear, they'll think about musical transitions, they'll listen to what isn't working musically in a song and figure out a way to tactfully redirect the musician at fault...then on Sunday, the spiritual and congregational component will be added - what is God saying, are people engaged, should we do that chorus again, and on and on. Point being, get there early and set stuff up. Take care of as much as you can before they get there so that they don't have to think about the tech stuff. Ask beforehand what players are in the band and set up the platform for that. Offer yourself as a proactive servant.
   

So what am I missing for the Best Practices: Audio?