As much art as it is science, there are myriad ways to ruin live sound and just as many ways to make it great. While some of these common sound-reinforcement catastrophes are strictly technical, you’ll be surprised how often the biggest issues require more subtlety to master. What follows is a far-from-exhaustive list of seven common live sound missteps that many of us have made. Here’s your chance to learn from our mistakes and save yourself time and frustration the next time you take over the board.
Mistake 1 – Boosting with the Faders
The first fabulous flub that awaits the unwitting live sound tech is botching the balance between preamp and channel-fader gain. Boost too little at the preamp and then try to make up for it downstream at the channel fader, and you won’t just boost the signal, but you’ll also boost any noise added to it by the preamp. The noise adds up and can seriously muddy the mix.
1. Set your channel faders to U
Indicated by the letter U or number 0 on most channel faders, unity gain is the point at which an amplifier (gain stage) neither boosts nor cuts (±0dB). This concept is important wherever you have an amplifier/gain stage in your signal path.
2. Boost input signal level with the preamplifiers
When you set level at the preamps, set the gain for each channel so that it is peaking between -5 and -20dB. Always leave extra headroom during soundcheck — performers always get louder when the show starts. Resist the urge to mix from the preamps.
3. Mix by cutting channel faders
Bearing in mind the way gain staging works, you should know by now that boosting at the channel faders will amplify any noise already in the signal path. What’s more, you’ve already mixed the incoming level as hot as the channel will allow. It logically follows that you should only use the channel faders to cut volume as you mix, so don’t push past unity gain.
Read all of the 7 Live Mixing Mistakes at Sweetwater.com
