On the Bus
The internal bus structure of a mixing console is also subject to headroom and S/N Ratio considerations. Whereas some consoles like to have their mixing busses driven hard, others’ buses can be clipped quite easily.

A good example of an inexpensive live console that needed its busses driven hard is an old Peavey console I had 30+ years ago.

There was a lot of noise in the mixing buses, but by running the output faders down around 2 or 3 (on a scale of 1 to 10) and driving the input stages a little hotter, it was possible to get a decent S/N at the outputs.

On the other hand, a more recent vintage Alesis 16-channel live console I used as a keyboard mixer didn’t have extra headroom in the mix bus but was very quiet. In that case, I ran the output faders up around 8 or 9 and then trimmed back the channel inputs until the output was at the right level.

The easiest way to determine the correct internal bus gain-staging approach is to plug in a dynamically consistent signal source, such as a drum machine or sampler, and listen with headphones for any crunching or distortion at the console output.

If there’s a lot of noise on the outputs with the faders up and no input signal present, bring the fader down until the noise is manageable.

Headphones make this easier to judge in a noisy room, so get yourself a quality pair and make friends with them.

If you hear distortion on the console outputs even when the meters read below 0 dB and the output faders are below halfway on the console, it means the internal mixing buses are clipping.

In that case, bring the input faders down and the output faders back up. High-end consoles have extremely quiet buses and a lot of headroom, so you typically won’t run into that sort of problem with them.

But many inexpensive consoles can be tweaked in the way I described to sound better than you might imagine. If you want to go further, you can use an oscilloscope and a signal generator to actually see flattening of the waveform and clipping in the various stages and adjust the levels accordingly.

Yes, it’s the ultimate geek thing to do, but oscilloscopes can be great troubleshooting tools.

Hit ‘Em Hard
You can also tweak the gain structure between the equalizer and the amplifier to improve the S/N ratio of the entire sound system.

For example, if you have sufficient gain from the equalizer’s output, you can raise its level by 10 dB and trim the input on the amp down by the same amount to attenuate any hum or ground-loop problems between the console and power amplifiers. That can really help in a quiet ambience mixing situation such as a church service.

Proper grounding, balanced inputs and shielded cables should, in theory, allow for an ultra-quiet connection between the console equalizer and the amplifiers.

However, that’s rarely the case in the real world. I’m always tweaking things one way or another to get the outputs as hot as possible without clipping and then turning down the inputs on the next stages.

End Game
Nearly any sound tech can properly operate a really expensive console with plenty of headroom and low noise, but it takes someone with real skills to make a cut-rate, unforgiving board sound great.

I have observed many guest engineers working with the same equipment get results ranging from fabulous to mediocre or worse, depending on how they ran the levels.

So don’t feel put down as a sound tech when you’re given some inexpensive gear and asked to make it sound great. Making an inexpensive system sound like a million bucks is the ultimate challenge. You can indeed spin straw into gold if you use your brains and experience.

Getting your church sound system to sound its best takes more than a great set of mixing ears for a particular music style.

It requires understanding how each piece of gear in the signal chain works and exploiting its potential to the max while working around any weak points.

Once you reach that level of knowledge, you are truly sympatico with the sound system and can make it do most anything you want.

Mike Sokol is the chief instructor of the HOW-TO Church Sound Workshops. He has 40 years of experience as a sound engineer, musician and author. Mike works with HOW-TO Sound Workshop Managing Partner Hector La Torre on the national, 36-city, annual HOW-TO Church Sound Workshop tour. Find out more here. 

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