multi-band compression article

[kent_powellpalmercay.com]

Not too long back on one thread, Craig referred to an article on this site on multi-band compression. Can't find it. Anybody got a URL? While I'm at it, anyone care to offer their general philosophy to applying multi-band, or point me to any other useful reference material on the subject? I understand it acts much like an EQ when used properly. What I want to know is how? Say you've got some 250Hz mud to clear out with Sound Forge. Whadaya do?

[miroslav]

To lose the "250Hz mud", just use an equalizer...Graphic or Parametric...your choice, depending on how "surgical" you need to be.

 

Use the multiband compressor just like you would any other compressor...to control dynamics.

 

The multiband will allow you to control which frequencies trigger each of the "multi" compressors just like a side chain in a single band compressor.

 

So if you have a 3 band multi-comp and your music has a lot of very low end that is dynamically "all over the place" you can take the 1st band and set your "side chain" frequency to match the music very low end. Then dial in the Threshold, Attack, Release, Ratio to your liking...WITHOUT dynamically affecting the low-mids, mids, mid-highs and highs.

 

Your music also has some mid-highs that are not "all over the place" but you just want to control some peaks. Take the 2nd band and set that "side chain" frequency to match the mid-highs and dial in the compressor parameters there as need also WITHOUT dynamically affecting the other frequencies.

 

And so on....

 

With a 6 band multi-comp you just have more choices.

 

 

As basic as I can describe it.

 

Miroslav

[kent_powellpalmercay.com]

Thanks for the reply. Actually, Craig made reference in another thread to an article on this site supposedly on multi-band compression. Couldn't find it. Anybody got a clue? Craig, if you're out there, where is it?

 

Failing that, I'd be happy to get any tips or helpful pointers.

[Anderton]

I did a search on "Compression" and the first three entries pointed to the article. It is at:

http://www.musicplayer.com/CDA/Player/Main/1,2000,Lessons-Keyboardist-92,00.html

 

A couple more tips:

 

With multiband dynamics, you can expand in some ranges while compressing in others. The article mentions doing this on a tune where the bass was just a sort of constant throbbing. Expansion gave it more dynamics.

 

The main point to remember about multi-band compression is that it's a cross between an equalizer and a compressor. It also prevents "breathing" and "pumping" that occurs with a single-band compressor, e.g., the kick hits really hard and triggers compression, which affects the high frequencies, even though those frequencies don't exceed the threshold.

 

I also use multiband compression a lot in situations like dance music where there's a lot of low-end "rumble" and high-end "sizzle." That often makes the midrange sound weak by comparison. If you boost it only with EQ, then it starts competing with the other frequency ranges. Lightly compressing the midrange will allow it to "pop" more without increasing in level that much. This is also a good technique for pulling a vocal out of a mix while mastering.

 

Real world example: a received some tunes to master where the vocalist was no longer in the band, but the record company liked the singer. The band had, purposely or not, mixed the vocalist back somewhat. Politics aside, in my judgement the vocals needed to come up, so I used a little midrange compression. The band ended up liking it, too.

[kent_powellpalmercay.com]

Many thanks to Miroslav & Craig! Any other mastering types care to chime in? Having listened to Craig's work on the Rei$$dorf Force tune and read the article, it's difficult to know when to use multi-band vs. EQ.

[Anderton]

>>it's difficult to know when to use multi-band vs. EQ<<

 

Think of multi-band compression as a specialized sub-genre of EQ. If all you need is more level in a certain band, then EQ is all that's needed. But if you need to also control dynamics in a certain band, then you need to use frequency-selective compression. Example: You want to make cymbals louder, bring up the EQ. You want to make the cymbals have a longer decay, compress the high frequencies. If you want a longer decay and a louder sound, compress the high frequencies, and turn up the level of that band.

 

Hmmm, that's probably clearer than how I explained it in the article . Make sense now?