Professional Mixing Tips for Church Sound

Running sound for a worship service can be tough. You might not have a lot of practical experience. Maybe the entire crew is made up of eager but unschooled volunteers. The sound system itself could be showing signs of age or neglect. Still, there you are, serving your church and hoping nothing goes wrong on Sunday. Sound familiar?

Worship services can either soar or crash at the mixing board. Is the low-end missing? Do the vocals and instruments lack clarity? Are you filling all the available frequencies? These questions evoke common symptoms of a mix in need of divine intervention.

Here are some helpful tips I've discovered in over 45 years of live mixing.

Listen to each instrument individually

CHALLENGE: Many sound techs forget to listen to what each instrument and voice really sounds like. If all you ever hear is the sound of the piano or acoustic guitar though a microphone in your PA system, you might be missing important elements of its sound.

SOLUTION: Ask performers to play their instruments or sing for you as you listen up close for the sonic qualities. Don't be afraid to ask them to play scales for you, play a few measures of the songs they're likely to perform, or sing their solo or harmony parts. While you're at it, find out if they like a particular microphone. You'll probably learn something that works for both of you. Communicating with the praise team is an important part of being on the sound crew, so don't be afraid to ask questions. They'll appreciate the opportunity to provide some input.

Another technique that works great is to get a good pair of headphones and solo each instrument or voice in the mix while listening carefully. Shure SRH440 recording and monitoring headphones are an affordable option. What does the kick drum really sound like by itself? How about the piano? Solo the vocalists and hear how they contribute to the harmony of a song. After a while, you'll be able to pick out the individual instruments in the room mix without headphones or solo buttons. You will have trained your ears (and brain) to pick out the sound of the hi-hat or snare or piano (or whatever) and adjust the mix in real time.

Know the frequency limits of each instrument and voice

CHALLENGE: Every instrument and voice has both low and high frequency limits. That is, there's a bass note that's as low as each singer or instrument can produce. And there's a top note plus harmonics that are as high as they can produce. Knowing the frequency limits of each instrument or vocal is very important to understanding how to equalize and mix them together.
 

SOLUTION: There are a number of charts that indicate the frequency ranges of each instrument and will help you understand how to equalize them. I built this chart when I was mixing symphonies and needed to describe the bandwidths of each instrument for the conductor.

Studying the chart will help you know what you can do with each instrument. For instance, you'll see that the lowest note a piccolo can play is 523 Hz. That tells us two things:

• Trying to add bass to a piccolo by turning up the 100 Hz bass control on your channel strip just won't work. There's no bass there to begin with, so there's nothing for you to boost. And …
• Any bass that comes into the piccolo mic channel certainly isn't piccolo. It's coming from something else like the bass guitar or percussion section and should probably be filtered out.

This is a concept I call frequency bracketing, and it's key to any great mix.

Also, you can see that vocalist really can't sing lower than 80 Hz, so that's when you apply the high-pass (same as the low-cut) filter at 80 Hz or so. If you have a variable low-cut filter on your console, you can adjust it to be just below the lowest frequency an instrument can produce. I set the low-cut filter on a piccolo to 400 Hz, or the low-cut on a violin to around 150 Hz since it can't make much sound below 190 Hz or so. I start all male voices with a low-cut filter around 80 Hz and female voices at 140 Hz. Just be sure to listen to how chopping off the bottom of the spectrum sounds for each instrument. Similarly, there's a maximum high frequency that each instrument can produce, INCLUDING its harmonics. So if you have a console with a variable HIGH-CUT filter, you can set it just above the the highest harmonics you want to hear. For example, there's not much sonic energy above 8 kHz or so for most kick drums, so I generally set the high-cut filter on that channel to 10 kHz. Use your headphones and the solo or PFL button.

Add flavor and texture with EQ

CHALLENGE: I often find that mixing consoles in churches have the equalization section of their channel strips set to what appears to be random values. Most of time I return all channel EQ to flat (the 12 o'clock position). I then make equalization decisions based on the two sections above. This means that you not only need to understand what each instrument is supposed to sound like, but also you need to correlate that sound with a number you can select on the mixing console itself.

SOLUTION: This is equivalent to the chef "adjusting" the soup with just the right amount of seasoning. It's something that takes years of listening and practice to do well. Below are a few suggestions for someone who is just getting started with EQ.

Understanding the channel strip equalizer

First and foremost, you need to understand how this part of your mixing console works. On any medium or large analog console, you'll probably have 4 bands of EQ with sweep midrange controls, plus a low-cut (or high-pass) button. The top and bottom controls marked HIGH and LOW are pretty easy to understand. The HIGH knob is something called a shelf EQ that will boost or cut everything above 12 kHz (12,000 Hz). The 12 o'clock U, or Unity, position has no impact on the sound. Twist it to the left, and it begins to cut all those frequencies. Twist it to the right to boost all those frequencies above 12 kHz.

The LOW control at the bottom of the channel strip EQ functions similarly. It adjusts the frequencies below 80 Hz or so, subtracting bass when turned to the left of the U position. When turned to the right of Unity, it boosts these same frequencies.

The LOW MID and HIGH MID controls are a little trickier to adjust since there are two knobs associated with each band. The FREQ control sets the center of the frequency area to be boosted or cut, and the -15 / U / +15 control boosts or cuts that particular frequency area.

(Note: Digital mixing consoles work similarly except they also let you see the actual equalization curve you're applying to the instrument or voice.

Associating numerical values to sounds

Next you need to associate the numerical values of the frequencies with what they sound like to your ears. The chart here describes each group of frequencies and what they sound like.
 

Sheen is that metallic sound of cymbals or violin strings at their highest frequencies. Add a bit more Sheen (maybe +6 dB) to make cymbals sound more alive.

Sibilance comes from an exaggeration of sound that projects from the roof of the mouth. You can tune it out by sweeping the frequency knob with gain knob boosted about 6 dB. Then listen for the really offensive point on the frequency knob and cut it by -6 to -12 dB.

Presence frequencies can make an instrument stand out in the mix without increasing its overall volume. So add maybe +3 dB at 4 kHz to give a vocal or guitar more "punch."

Vocal Intel frequencies are where we understand the words. So apply +3 dB of boost around 1,000 to 1,500 Hz if you want words to be more intelligible.

Nasal Honk is that nasty group of frequencies that sound like you have a cold. I generally cut a few dB around 600 Hz to get rid of the honk on vocals and percussion, especially on kick drums.

Tubbiness can happen to instruments such as acoustic guitars that are shaped like a tub. I generally cut a few dB around 200 Hz to clean up the lower register of the sound.

Boom can be useful on shell and floor toms, but not so much on snares. So I'll often get rid of some of the 100 to 150 Hz tone of a snare drum, but I'll probably boost the floor toms a bit in those frequencies.

Deep Bass is usually reserved for kick drums and bass guitars. But do your boosting sparingly since it's easy to overload the woofers in your PA system. Let your ears be your guide.

It's hard to learn and apply all of this in the middle of a worship service since you don't want to make mistakes with the congregation present. So, below is a way to practice your skills during downtime.

Make a recording of your pastor speaking, then spend a few hours just playing with all EQ knobs and listening to the results. Do the same for members of your praise band. See if you can record a few minutes of each of them playing or singing, then begin experimenting. Most digital mixing consoles have an easy way to create something called a Virtual Sound Check, which records each instrument on its own track on a computer. Then you can play back the tracks at your leisure and tweak and adjust for hours. And nobody needs to hear it but you. Practice, practice and practice.

Final Thoughts

One of the great things about sound engineering (in churches or in clubs) is that there's always something new to learn. Even seasoned veterans like me are always picking up tips and tricks at industry events, in pro audio publications and from other sound pros who are generally happy to share.

Keep learning. You'll develop skills along with an audio crew worthy of praise.