A reader question re compression and limiting on the master bus
Our friend Albert Niemoller sent me an excellent question today, and I thought that perhaps someone else might have the same question and might find some thoughts on it helpful! Albert wrote:
I've read your previous post on having a compressor and limiter on the master bus when mixing and that makes total sense to me given the loud rock music I make. But slamming my track into a compressor and limiter is also what I think of as part of mastering.
So do you do it again in mastering or is mastering for you just what you do on your master bus when mixing or something else?
And I replied:
Hi Albert! I have a compressor and limiter on the master bus when I'm mixing all of the time, irrespective of genre. I consider this a best practice, for two different reasons:
- Unless you're doing classical or some kinds of jazz, you will want master bus compression on your mix for modern music. And you will want it there first, before you start mixing, so that you "mix into" it. You get better mixes this way, because you can react to how the compressor is reacting and push things into it in a way that causes wonderful dynamic interaction with other elements in your mix.
- Working with a limiter, at mastered loudness, forces you to confront and address issues that otherwise might show up as unpleasant surprises in mastering. When mixes collapse in mastering, it's generally because the person mixing hasn't subjected their mix to a limiter and is therefore completely unaware how, for example, the kick drum may lose some of its intended volume or impact when it finally does hit a limiter in mastering.
You can be guaranteed that your mix is going to hit a limiter — so you might as well work with it on there yourself, so that you can see what’s going to happen and do what needs doing to address it, instead of leaving it to be a surprise!
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When I'm mastering my own mixes, I bounce out of Pro Tools at -10 dB less than mix volume, with the limiter bypassed and all other mix bus processing active (compression, EQ, saturation, clipping, tape, etc); I use a gain plugin before the limiter, set at -10 dB, to achieve this. Then I redo the limiting in mastering, along with anything else I see a need to do.
I've written previous Jamie's list posts that touch upon these ideas in further detail:
Regarding the compression component, you don't have to "slam" your mix into a bus compressor. You can do it gently! I'm generally doing 2-4 dB of compression on my mix bus in a modern genre (rock, pop, rap, etc). That's not really slamming it in there; it’s more like nice glue, for cohesion, interactivity, and a "finished" sound.
And to the question about whether you should leave this for mastering ... definitely not! You should get your song sounding as close as you can to finished before going to mastering — and that very much includes mix bus compression.
One reason for this is that the character of the mix bus compression can completely change the character of your mix. And that’s a decision that you ideally shouldn’t leave to someone else!
And the other reason is that mix bus compression and mastering compression are pretty different. Mix bus compression is often a 4:1 ratio (of course this can be different depending on the song), and often more active; mastering compression is often a 2:1 or lower ratio, with different attack and release than you might use for mix bus compression, and often more subtle.
Also, if you don't compress your mix bus, the elements in your mix may not respond well to compression applied after the fact; they may push one another out of the way in a way that you hadn’t intended, which you would be able to respond to and use to your advantage if you were mixing with compression on there. So definitely mix with it!
Main squeeze — jamie