Gain staging used to be a crucial consideration for analogue recording and mixing - but you’ll hear plenty of people saying it doesn’t really matter, in a modern digital audio workstation. And they have a (floating) point.
But you’ll also hear lots of other people, me included, saying it IS important to understand what gain staging is and how it works, even in a digital environment.
So who’s right ? In this show we dig into the details, and discuss:
- How much peak headroom should you leave before mastering ?
- What IS gain staging, anyway ?
- Why do people say it doesn’t matter in digital ? Or:
- What’s the point of floating point ?
- How does it work ?
- When digital gain staging does matter
Links
How much headroom is needed before mastering ?
TMS #26 - Clipping: What is it, and is it ever acceptable ?
See this stuff in action on the Home Mastering Masterclass
TMS #21 - Why digital “resolution” doesn’t exist – because dither
Great subject--nerdy or not, this is such an important topic for digital-based recording engineers.
I find gain staging can usually be easily accomplished in any DAW by inserting a gain/trim plugin within the channel strip, but it should be inserted at the appropriate part of the signal chain/path.
For example, if I can clearly see that my guitar input signal going through my Audio Interface is hitting around -18db where it should, but when its running back through a processed, preset Logic Guitar Amp Channel Strip its peaking at -3db, then I'll inspect the last plugin of the signal chain, and begin there.
Now if the last plugin is an EQ, instead of changing the output level of this effect, which may affect the tonal characteristics of the channel strip itself, I usually insert a Gain Utility after the EQ and then adjust the gain level to peak once again at -18db. In this way, you retain all the original 'specs' and/or tonal characteristics of the designed sound. I'll often record dry guitar parts like this so I can re-amp or tweak them later if need be to better fit the mix.
Often times a guitar amp/modeled channel strip will contain several plugins which create or makeup the sound, like a pedal board plug on top, going into an amp plug, into an eq plug, and finally into a compressor plug. Now if the last plugin of the signal chain is a compressor, then you might achieve the same result by lowering the output on the compressor. However, this is where you'll have to listen closely to determine if the overall tone is being affected, whereby again, you could simply insert a Gain Utility plugin after the compressor to address any gain staging issues.
I say this because even though lowering the amp plugin's output on its own would change the level as well, it will usually also affect the level going into the next plugin like a compressor, thus changing how the compressor reacts and sounds, and so on with whatever plugin's are applied/inserted after the amp.
This approach can be applied to any source signal or channel strip within the DAW's mixer. I do this for every project I'm mixing to ensure I maintain plenty of headroom on the main out before inserting any plugins on the mix bus. Although it is possible to insert a single gain or trim plug at the top of the mix bus to achieve the 'same looking' metering goals, I prefer to address each track on its own, treating each track like I would in an analog format, like in coming back into the mixing desk from the tape machine.
With the understanding that everything digital now is a substitute for what was originally done using only analog gear, I find treating the gear like it is analog being used in an analog setting helps to achieve better mixing results. I am not aware of any DAW that presets its mixer with a trim knob at the top of the channel strip like you would find on every analog mixer. So engineers must now apply this trim knob as and where needed. I should note that all of these adjustments are always made while monitoring in Pre-Fader Metering mode.
Hi Jimmy,
I work in the same way. I throw gain plugins and meters in before and after every plugin to keep the level around -16 db. I started doing this after reading or hearing somewhere that plugins are developed to "expect" a signal level of around that magnitude. When I heard that advice, it made too much sense to ignore.
No matter what I alter later, ( <= anagram!!) in a particular signal path I always do a check with a meter afterwards and if needed alter gain into one plugin, or reduce/increase output of a plugin. The exception is when I'm using a plugin for its colouration and then I may increase the input level to that effect (Kramer HLS Channel is a good example; another is Klanghelm SDRR Saturation).
Ian and Jon - interesting talk, thank you!