Multiband compression

[Mostess]

Seems like everyone is doing it, especially for mastering. Here in HM-land, we have only DirectX plugin capability and no funds for plugins, so (unless I haven't devoted enough time to finding a free DirectX multiband compressor) I've decided to try to do it myself.

I imagine if I take my mix and put it on 3 tracks, apply a low-pass EQ to one, a band-pass to another, and a high-pass to a third, then run each through it's own compressor, I'll be doing what the multiband compressor would be doing. Correct me if I'm wrong.

Does anyone else do this? What filter cutoffs work best? Is it a good idea to mix in an uncompressed, unfiltered track as well? I already know that trying and listening is the best way to find out---I'm curious about others' experiences?

[starfinger]

i think the trick will be the regions where they overlap (which is inevitable because the filters don't have a perfectly vertical slope). dedicated multiband dealios have to do special things to make the crossover areas sound right.

-craig

[blue]

i think you'll be in phase / eq hell.

[bz£]

I've seen a few free VST multiband compressors and my favorite at the moment is GMulti, probably because it is has a nice, calming blue and grey interface that makes me happy. If you can't directly use VST effects you can get a "wrapper" effect, which would (in your case) make VST plugins work with your host. An adaptor, basically. It's a little inconvenient but probably a lot easier than what you're currently doing.

[deshead]

a free DirectX multiband compressor

Ya, I don't know of any either.

However, Spinaudio makes a free directX vst-wrapper. It's limited, but should be enough to get you running bzl's suggestion, MDA's multiband compressor, Breebaart's Broadcast multiband compressor or this bad boy: http://www.geocities.jp/webmaster_of_ss ... ex.html#c3

I'll be doing what the multiband compressor would be doing. Correct me if I'm wrong.

Craig's right that the crossovers are critical. However, if you use the same parametric equalizer on all 3 tracks, with the same Q setting on each, that should ensure the cutoffs match. (A quick test with 2 Waves REQ's suggests this is the case.)

As for cutoffs and filters, Ozone uses 120Hz, 2KHz, and 10KHz as the default crossover points, and a Q of 5. Waves C4 uses 92Hz, 4000Hz, and 11000Hz, with a Q of 0.6.

I'm sure either of those would make a god starting point for experimentation.

i think you'll be in phase / eq hell.

Yeah.

[Mostess]

i think you'll be in phase / eq hell.

Yeah, the VST-wrapper is probably a good idea since DirectX seems to be the Betamax of plugins at this point. Whole new worlds of effects and virtual instruments would open to us. Not that we're even close to figuring out what most of the stuff we already have does...

So I probably won't try the manual idea. Forget I said anything.

Except, unless it's a can or worms that should stay tightly shut, may I ask...phase hell? If my tracks are all copies of one file, all time locked together, how would filtering and compression introduce phase issues?

[deshead]

http://equalizers.indepthinfo.com/how-e ... orks.shtml

Most equalizers work by mixing a signal with a delayed copy of itself. The delay causes certain frequencies to go out of phase, and thus cancel or re-enforce eachother.

Putting 3 separate equalizers on a signal could introduce unintended delays, and lead to phase/eq hell.

[Mostess]

Most equalizers work by mixing a signal with a delayed copy of itself.

Holy crap. Thank you. I had no idea.

[Adam!]

Seems like everyone is doing it, especially for mastering.

A lot of hobbyists are using multiband for mastering. God knows I sure did until recently. But one interesting thing--I know, I know, I've been ranting about this recently--is that most pro's don't master using a multiband unless there's something really wrong with the mix. This thread on Gearslutz really opened my eyes: almost none of the people who run professional mastering services use a multiband. The rationale for not using one is simple: anything that would need to be fixed with a multiband compressor at the mastering stage should really be fixed in the mix.

Anyway, I agree with Blue: the phase problems are gonna be whack.

[bz£]

The only thing I use it for is when I've recorded an entire drum kit with one (or maybe two) microphones. You can't really separate kick, snare and cymbals when they are all on one track, but you can cheat with a multiband compressor.

As always, remember that nobody likes any of my songs so you should be careful when following my suggestions. This seems to work out okay, though.