Gain Staging: What is It?

Gain staging is one of those concepts that many modern recordists don’t fully understand. This may be because it’s a little different in the digital world, but it’s still important. And of course, in live audio, everything is still analog. So, it’s a good idea to get a handle on gain staging.

What is Gain Staging?

Gain staging is simple, at least on the surface. It’s merely the process of setting the right level at each point in an audio signal chain. Typically, what “right” means is simply that things sound good and they remain sounding good at the end. What this generally means is that the signal is strong enough to drown out the noise floor (the audible hiss that all analog equipment emits) but not so strong as to cause unwanted distortion.

That’s quite simple at each point in the chain but planning for the accumulation of noise or distortion over the course of many stages is important – this is called “gain staging.”

Analog Gain Staging vs. Early Digital Gain Staging

In essence, there isn’t a difference between gain staging in the analog domain and the digital domain, because the ultimate goal is the same: keep things sounding good. However, there are a couple differences, one of which can mislead digital-only engineers into thinking it doesn’t matter.

In the analog domain it’s simple – overdrive any stage in the chain and you’ll be amplifying a distorted signal the rest of the way through. Sometimes a little bit of this kind of overdrive is desirable, so in the analog domain there’s a little wiggle room – depending on the genre and track. Judicious distortion on a guitar, for example, might be great. On a vocal, not so much.

In the digital domain – at least originally – no such wiggle room existed. In any fixed-point system, say 16-bit or 24-bit, once a signal goes past 0 dBFS clipping occurs, and the signal is ruined. This rarely sounds pleasing or desirable and just as in an analog chain, it can’t be reversed by turning the gain down at the next stage.

In this situation, gain staging in the digital domain is the same process as in the analog domain. At each stage, make sure the signal is strong enough to get past the noise floor, but not so loud as to distort the signal. Except that with digital, there’s no room for wiggle at the top. And the noise floor is typically lower. However, there is one more caveat about digital gain staging nowadays.

Modern Digital Gain Staging

Most digital audio workstations (DAWs) these days use floating-point processing. What this means for gain staging is that there is now some room for error. Sometimes, you can even reverse clipping by turning the gain down at the next stage. Say if you have slight clipping on a channel and turn the buss it goes to down a bit.

This probably explains why many newer engineers don’t think much about gain staging. However, it’s still important, for a few reasons. One is that some plugins in the chain may not be using floating point processing. Another more pressing problem is that modern analog emulation plugins emulate analog gear very well – meaning they will distort just like their analog counterparts. This may be desirable, and it may not. Furthermore, many, if not most plugins have an optimal input level (usually -12 dB or -18 dB), so it can make quite a difference to make sure to hit those input levels.

All of which to say that although gain staging in a modern, floating-point DAW is less of an emergency, it’s still an important thing to pay attention to.

Gain staging isn’t complicated or hard. It’s simply a matter of paying attention to detail and setting a good level at each stage (everywhere there’s a gain or volume knob!) instead of simply cranking one stage until it’s loud enough and wondering why there’s hiss, distortion, or both.

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