Got this question about mix bus compression from a justifiably confused reader:

"You state that you should clear your master bus of any bus compressors before mastering - but..you...advise that we should 'mix' into the master bus compressor as early as possible when mixing and this is what I've been trying to do.  It surely doesn't make sense to do this and then remove the master bus compressor before mastering, whether you're mastering yourself or not.  Or have I got the wrong end of the stick? I'm hoping you can clarify this for me?"

Gordon's question is in response to a previous article about making things ready for mastering, where I say,

"Don't leave your Ozone mastering plug-ins and buss compressors on the master bus when you bounce your mix down to a stereo track. Leave that processing up to the mastering engineer."

I've actually flip-flopped a bit on this issue because I tend to do a lot of processing on the mix bus while mixing. I talk about the top-down and middle-out method inside Step By Step Mixing. a book people have been calling a "mind-opening book on mixing."

The Mix Bus Compression Process

When I mix a single song for release, I usually do my normal mixing, through a mix bus compressor the entire time. Then, when I'm satisfied with the mix I'll add my mastering processors, like multi-band compression, Ozone and the like, until I'm satisfied with it sounding like a final master.

I also do this sort of quick 'n' dirty mastering when I bounce final mixes for artists to listen to and give approval. I want the songs to sound loud, cohesive and glued together like a record while they're listening to the final mixes. That way they won't feel disappointed in my mixes if they play them next to something else they like.

Once the artist is happy with my mixes, I usually give the songs to my studio partner who does the mastering. It's nice to get a second set of ears for the mastering so whenever a band hires us to work with them, they get a separate mixing and mastering engineer, as well as a defined engineer and producer.

However, once that happens I usually take off the quick 'n' dirty mastering chain so that there's more headroom to work with and the songs can be mastered together to sound like a record instead of just a playlist of similarly loud songs.

So in a nutshell, my process is this:

• Always mix into bus compression from the start after getting a rough fader/pan mix, just for a little glue.
• If I'm mastering a single song I'll master the mix at the end, using specific mastering processors.
• If I'm mixing a record that'll be mastered together I'll take the mastering processors off and let the mastering engineer do their own magic.

The compressors I use on the mix bus are usually pretty tame. They're just there for light glue and tightness overall. If you'd like to see my entire process of compression in action on a mix, along with how I use EQ, reverb, delay and saturation as well, I highly recommend jumping on the video course version of Step By Step Mixing called Mixing With 5 Plug-ins you can find on the same page.