Advanced Overcomplication -OR- Compression Madness
So I realized in my last post that I opened a can of worms on all the wild and crazy variations of using compressors that get thrown around if you troll some of the many audio forums on the Net. This will hopefully serve as a basic explanation of some of a few of the different ways you can use compressors in mixing. I’m sure there are more than just these, but here’s a primer. Bear in mind, however, that if you haven’t mastered using a compressor to begin with, you should probably stay clear of anything beyond the Traditional compression. In fact, you can check out a post I did last year on learning how to use a compressor if you’re still fuzzy on the whole thing. Another thing to keep in mind is that most of these techniques come out of the studio; increasing the amount of compression you’re using in sound reinforcement can have the adverse effect of decreasing your gain before feedback if you’re not careful.
This is your standard method of using a compressor. You have a signal, it hits a compressor, and then it hits the master bus. Most commonly, the compressor would be inserted on an input channel. It might also be on an output buss or any other number of places in between. It could also be pre- or post-EQ in any of those locations. Regardless, this is sort of the tried-and-true method of implementing a compressor; one compressor doing the compression thing. This is the most basic use of a compressor and a skill that should be mastered before attempting any of this other stuff.
Parallel compression is a technique that developed out of recording studios in NY I believe in the 80’s. It’s sometimes referred to as NY Compression or Upwards Compression. The idea is you take a signal and split it or mult it so that you have it on two channels or busses. You compress one of the mult’s a bunch and the other one is either uncompressed or lightly compressed. Then you blend the two together. It’s called parallel compression because you have a signal with a compressor running parallel to your standard signal.
This is most commonly used on the drums where your parallel compression takes place on a drum bus. I’ve also heard of doing this on vocals and even bass. The result of this is tighter and punchier drums while retaining more of the original dynamics. It’s almost a texture or a color thing.
Serial compression is pretty simple. It’s basically two or more compressors in a row. This is typically done so that you can run lower ratios to achieve more compression with less of the negative sound-effects of compression. Sometimes maybe you use a fast-ish attack/release on the first comp to tame the peaks and then use something a little smoother on the second one to level the whole thing a bit more.
Two Stage Compression
Two Stage compression is something new to me. I guess Mike Caffrey did an article about it in TapeOp a couple years ago. He also has a couple of YouTube videos you can see here and here. In a nutshell, Two Stage Compression is sort of the next take on Parallel compression. You have your parallel compression happening and then you feed those channels/busses into a compressor. If you look at the diagram above, you’ll notice that the signal path is VERY similar to parallel compression, but the key is where you place that final compressor. I’m honestly not sure this method even bears mentioning since it’s really just an evolution of parallel compression, but if you dig around on forums you might hear about it. I have never experimented with this so I can’t really comment much on it directly.
Multi-bus compression is a method made famous by Michael Brauer(John Mayer, Coldplay). He developed this in response to some challenges he was having using a compressor on the 2-bus of his mixes. Instead of using one compressor for the entire mix, Brauer organizes his inputs into multiple busses(these days he typically uses 4) and uses a compressor on each bus best suited to those particular sounds. This way he is able to more appropriately color his instruments with the right compressor for the job.
Another thing to note is Brauer’s use of compressors is typically post-fade so that he is mixing into the compressor. This gives him a lot of flexibility to change the character and color of the compressor simply by changing a fader. A few weeks ago, Brauer twittered about how this technique helped him with a mix for the upcoming John Mayer record. You can find out more about this method at Brauer’s site.
Next up I will talk a little about how I’m employing some of these methods in my mixes.
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