Gain Staging/General Principles
Contents
Gain Staging / General Principles
We are talking about getting the best gain-before-feedback (and the highest signal-to-noise ratio while we are at it). We are not talking about deliberate choices you can make to alter the sound through less efficient gain staging. So we will set aside: working the microphone, lowering sensitivity to get rid of unwanted sounds, and those instruments like Electric Guitar where deliberate manipulation of the gain staging and the resulting distortion is part of the sound.
Simple Language - General Principles
Let's drop the terminology for a minute and talk about what is going on and what we are trying to do.
Assumptions
that will affect you how you approach this
- Every step in the signal chain is an opportunity to pick up noise. It is probably already there, so you want to avoid amplifying it.
- Every time you amplify something in the signal chain, you are amplifying the noise too.
Principles
Start Strong
Start with a strong input and avoid amplifying along the way (until you get to the final output stage).
Less is More: Mixers and Effects and Gain
We're talking about mixers and effects processors here. If you can pass the signal through a device without affecting the level, you're probably doing fine. This often looks like a setting of "0" and is sometimes called unity gain. The idea is that you are neither amplifying nor attenuating (diminishing) the strength of the signal.
Amplify Early
If you have to boost the signal, do it as early as possible in the signal chain.
This means, if you have a two places where you can boost the signal, choose the one closest to the source.
Examples
- Choice: microphone or input trim?
- Preferred: Raise the level of the microphone. Move it closer to the source and if possible, make the source louder.
- Choice: On a mixer ... input trim or channel strip
- * Preferred: Raise the level on the input trim. Note: If it's not clipping, it's not too high.
- Choice: On a mixer ... channel strip or master output
- Preferred: Raise the level on the channel strip. Note: If you have to get above "0" or unity, go back to the beginning and try to get a stronger signal.
- Choice: Mixer or Power Amp ... mixer master output or power amp trim
- Preferred: Raise the level with mixer master output.Note: If you have to get above "0" or unity, go back to the beginning and try to get a stronger signal.
Cut Late
This is the same as the above described a different way. If at some stage the signal coming in is too strong, turn it down at the receiving end. That is, turn it down at the end farthest away from the source.
Say it ah... Gain?
Every time you amplifying the signal, you are amplifying the noise. So start strong, keep the level constant, if you have to... amplify early, and cut late.
This originally appeared in General Principles ST's blog