"Should I use a buss compressor on my mix ?"

That's a question I get asked a lot, and as a mastering engineer, I'm conflicted about what advice to give. The follow-up, "should it be single or multi-band ?" is easier to answer, though.

First of all:

Why would you use a buss compressor over your whole mix anyway ?

This post started out as a comment on The Recording Revolution about buss compression, and Graham's video from that post (above) gives a good explanation.

He's pretty clear that you should compress your whole mix, and the truth is that almost all "name" engineers in the pop, rock and indie genres, will slap an SSL or similar buss compressor over the mix as one of the first things they do when setting up a mix.

Simple, right ?

Well... maybe. A great buss compressor used on a great mix will often "glue it together" nicely, as Graham says. It's a tried and tested technique that has been used on a huge number of hit records.

BUT:

As a mastering engineer, I've heard more over compressed mixes than I've had hot dinners.

OK, not quite that many, but you get my point. For whatever reason, this is an aspect of the mix that people get badly wrong. A LOT.

And what that means, is mixes that are

• Dull, and lifeless
• Pumping - and not in a good way
• Heavily compressed but still not "glued" in the way you want them to be, or even
• "Smashed" and distorted

And unfortunately, it's almost impossible to remove the effects of too much compression. Sometimes you can help things out a little bit, but often by this stage it's too late.

When this happens, I gently point out the problems to my clients, and ask if they have a less compressed version, and often the answer is "no" - or more likely, just that there isn't any time left to sort one out.

So as a mastering engineer, I'm often tempted to say to people - DON'T use a buss compressor.

BUT:

Then they lose all the benefits ! Buss compression done right is a key component of a great sound in many modern genres. And if their goal is great sound like the classic tracks in their collection, it's a skill they probably need to learn - sooner, rather than later.

So hopefully you can see I have dilemma. (That doesn't mean I'm going to duck the question, though - keep reading !)

Buss Compressor "Do's" and "Don'ts"

If you want to use a buss compressor:

DO: Add it early in the mix process

Slapping something over the mix as an after-thought will unbalance all the decisions you've made so far, and likely end up in an over-compressed mess.

DON'T: Push it too hard !

I was really relieved at the end of his video that Graham eased back on his settings and stressed the importance of listening out for over-compression. To find out how to avoid over-compressing your mix, click here.

DO: Get the best buss compressor you can lay your hands on

It's possible to get a good sound from the "stock" compressors included with most DAWs, especially if you stick to gentle compression. However the hardware "classics" like Neve, Fairchild and SSL all have pretty decent plugin emulations these days by UAD, Waves and others - and they could well add an extra certain "something" that the others may not. (To see an example of a more affordable plug-in candidate, click here.)

DON'T: Assume you have to compress everything

Alan Parsons famously put the whole mix of "Dark Side Of The Moon" through a buss compressor - but not the drums. Rules are made to be broken, especially rules of thumb !

DO: Listen carefully

If a mix isn't happening for some reason, try knocking the buss compressor out, and see if it sounds better. If it sounds right, it is right - but don't overdo it. (Metallica, I'm looking at you !)

So - should you use a buss compressor on your mix ?

Yes.

And... No.

Depending.

Seriously though - Yes, if you're mixing pop, rock, or anything vaguely "alt", you should probably be using a decent buss compressor. Just remember - take time to learn what it does, and - less is more. Always listen carefully. Keep an eye on the TT loudness meter, and if you're constantly going into the orange or the red (for a mix) make sure you're happy with the results.

And finally, most importantly - if you're in any doubt about the end results, do a separate mixdown for your friendly neighbourhood mastering engineer with the compressor in bypass (and remember to reduce the gain if the output starts clipping !)

Take both to the session - that way he or she will know what you were aiming for, and give you an honest opinion about the end result.

In fact, maybe you should do that even if you're not in any doubt - just to be on the safe side : )


- Oh, I almost forgot !

Should I use a multi-band compressor on my mix ?

No.

This one really is simple. Here's why:

• The light "pumping" effect of a classic buss compressor is a key part of the sound.

Multi-band compressors don't do this unless you push them WAY too hard (which is a Bad Thing - see above.)

• Mixing into a multi-band can actually be easier - because it's doing a lot of the hard work for you.

By their very nature, multi-bands even out mixes, pull things together and level out dynamics - in other words, it's doing lots of the mixing work for you ! And that is not a good thing - there's no way a plugin can be a substitute for your ears and musical taste. When mixing, anything a multi-band compressor can achieve is better done by hand.

Mastering is a whole other story of course - keep an eye out here for more on that subject soon...


PS. Do you use buss compression ? Why ?

PPS. I've decided to enable Facebook comments as an experiment - feel free to try them out and let me know what you think !