years go by, I still hardly understand compressors

knotkranky · Post by **knotkranky** » Mon Dec 11, 2006 7:03 pm

Here's my simplification.

Attack: Adjust for the instrument size- A kick drum and bass are wide and have deep low end. Low end needs more time to reach full cycle. ie set the attack slow to allow the instrument fattness to get through. Around 30 and up ms.
Snares and plucky things like guitars and stabby synths have shorter wave cycles and need less time to get through ie about 10 - 20 ms on the attack. hats are very high and require tighter attack time and so on.
Slower attack lets transients through and faster chokes them off earlier.

Release: the amount of time for the compressor to reach its doing nothing state. If set too slow it will not have reached back to zero before the next transient. Too fast and attacky sounds with long tails will sound pumpy.

Ratio: 2 to 1 means a 2 db level increase will allow the gain output to increase 1 db holding it back 1db.... 4 to 1 allowing a 4 db increase to get a gain of 1db holding back 3 db etc.

Threshold: is the input to the compressor ratio detector. Its the gain to the chain of compression events. Call it side chain level input if you want.

Since a full song has all the sounds and is full band, slower attack time and fasterish release will do best. At that point song tempos and impact dictate how to set these.

Most mistakes are from too fast of an attack. You really have to nudge it all. Don't set one thing and move on, each control is dependent on the other at all times.

Don't be afraid to turn the hell out of the knobs. Swing them hard from 0 to 10 and use both hands on two setting if you have a hardware
compressor or assign a couple controls to software ones and move them hard at the same time to get a feel. Then slowly groove that into a place, shortening the throws of the knobs or faders until it settles in a vibe you like.

Then widen the attack a little cause it might be to tight anyway

Spiralgroove · Post by **Spiralgroove** » Mon Dec 11, 2006 7:05 pm

its not you, its them

steve-o · Post by **steve-o** » Mon Dec 11, 2006 7:38 pm

http://www.harmony-central.com/Effects/ ... mpression/

Another tutorial that helped clarify things for me, at least

leisuremuffin · Post by **leisuremuffin** » Mon Dec 11, 2006 9:10 pm

good on you KK, best job so far, but here's even simpler language:

Threshold --- level at which compressor starts working. (compressor triggers it's attack when signal crosses this level)

Ratio --- KK, of course you nailed this, but it helps to remind folks that it happens at the threshold ---> So 4 - 1 means that for every 4db a signal goes over the threshold, the signal is only allowed to increase 1 db over the threshold. So 10 - 1 would mean for every 10dbs a signal goes over the threshold it is only allowed to increase by 1db over the threshold.

attack and release i couldn't say any better.

and this is what it's all about. knowing what the parameters do. From there you just play with it until you get something you like.

.lm.

knotkranky · Post by **knotkranky** » Mon Dec 11, 2006 9:43 pm

leisuremuffin wrote:good on you KK, best job so far, but here's even simpler language:

Threshold --- level at which compressor starts working. (compressor triggers it's attack when signal crosses this level)

Ratio --- KK, of course you nailed this, but it helps to remind folks that it happens at the threshold ---> So 4 - 1 means that for every 4db a signal goes over the threshold, the signal is only allowed to increase 1 db over the threshold. So 10 - 1 would mean for every 10dbs a signal goes over the threshold it is only allowed to increase by 1db over the threshold.

attack and release i couldn't say any better.

and this is what it's all about. knowing what the parameters do. From there you just play with it until you get something you like.

.lm.

Cheers lm

yeah man, it's also important to know that one is setting a dynamics wave.
Once the threshold is crossed the parameters are put into motion and that
dynamic wave is superimposed on your music wave form. There is a spot where they mingle
in a pleasing way. It's not unlike the analogy of a rock into a pool and the ripples of frequency.
Same with a compressor, one can set the size and frequency on the control ripples.
Even the size of the crest and the space between them. You're really controling a wave with a wave.

leisuremuffin · Post by **leisuremuffin** » Mon Dec 11, 2006 10:51 pm

yeah, for sure!!

this is another reason i think programming modular synths should be a prerequisite for anyone interested in making electronic music or being an audio engineer:

since i was a synth geek before i got into audio engineering, i already understood what a VCA was, and what an envelope was, and it was therefore easy to see how a compressor worked ----> simply a VCA with an AD envelope that is triggered by the level of an incoming sound. (of course it's not really that simple, cause there's other things that could happen too, like maybe an vactrol circuit instead of the standard vca, or using another signal (or the same signal filtered) as the key input for threshold, but all of those concepts are in modular synthesis...)

The cool thing is that when you look at the compressor like that, it opens up the possibilities of what you can do with them. For instance, i often hear folks define a compressor as a tool for "reducing dynamic range." Well, OK, but knowing how the parameters work means that you could actually *increase* the dynamic range of a sound. ----> long attack + high ratio + lots of make up gain = louder and snappier transient than unprocessed sound!! Obvious to us, and one of the oldest trick in the book, but shows what you can do when you think of how the device works instead of what it's *supposed* to do.

I really like using compressors to do different kinds of stuff. One of my biggies is doing drum buss compression with them, but throwing a high pass filter up before the comp. then i mix that compressed signal back in with the dry sounds and get nice crisp and excited mids and highs..... Also a very old trick, but super effective, and as applicable to electronic stuff as it is to "real" instrument stuff....

.lm.

p@nts · Post by **p@nts** » Mon Dec 11, 2006 11:35 pm

I'd like to hear Peeeedrooo chime in on this subject. I think I'm hearing some tasty compressor abuse on a lot of Justice and SebastiAn tracks, but I'm not sure...

Sales Dude McBoob · Post by **Sales Dude McBoob** » Mon Dec 11, 2006 11:43 pm

Funny. I feel the same way sometimes, even though I've read endlessly about it, used a 100 different kinds of compressors, and I even end up explaining how to use them to people everyday.

But isn't that just the kind of thing that keeps us obsessed with audio???

Johnisfaster, I look at it this way. Everytime I open or plug in a compressor, it feels new. I'm honestly not sure what is going to happen. Sometimes I can make things sound better or huge, and other times I swear the damn thing isn't on because the sound is unaltered no matter what. The only thing I can rely on is my ears. I twiddle till it sounds good. That's as scientific as I get in the end.

I like to think of the user manual that came with my Distressor:
"Just put all of the knobs at 5 and go from there."

knotkranky · Post by **knotkranky** » Mon Dec 11, 2006 11:49 pm

leisuremuffin wrote:yeah, for sure!!

this is another reason i think programming modular synths should be a prerequisite for anyone interested in making electronic music or being an audio engineer:

since i was a synth geek before i got into audio engineering, i already understood what a VCA was, and what an envelope was, and it was therefore easy to see how a compressor worked ----> simply a VCA with an AD envelope that is triggered by the level of an incoming sound. (of course it's not really that simple, cause there's other things that could happen too, like maybe an vactrol circuit instead of the standard vca, or using another signal (or the same signal filtered) as the key input for threshold, but all of those concepts are in modular synthesis...)

The cool thing is that when you look at the compressor like that, it opens up the possibilities of what you can do with them. For instance, i often hear folks define a compressor as a tool for "reducing dynamic range." Well, OK, but knowing how the parameters work means that you could actually *increase* the dynamic range of a sound. ----> long attack + high ratio + lots of make up gain = louder and snappier transient than unprocessed sound!! Obvious to us, and one of the oldest trick in the book, but shows what you can do when you think of how the device works instead of what it's *supposed* to do.

I really like using compressors to do different kinds of stuff. One of my biggies is doing drum buss compression with them, but throwing a high pass filter up before the comp. then i mix that compressed signal back in with the dry sounds and get nice crisp and excited mids and highs..... Also a very old trick, but super effective, and as applicable to electronic stuff as it is to "real" instrument stuff....

.lm.

Well damn lm, i didn't know you got deep like that, kudos.

Yes the buss compressor. I use it often and it's popular with most good mix engineers. Nice one. Works with tons of stuff too. Fun to abuse really.

Tone Deft · Post by **Tone Deft** » Tue Dec 12, 2006 12:01 am

knotkranky wrote:Well damn lm, i didn't know you got deep like that, kudos.

Don't even get him started on blocking bass ports.

Good thread! I laughed, I cried, I learned.

frisbeedisk · Post by **frisbeedisk** » Tue Dec 12, 2006 12:07 am

Jeroen wrote:justin wrote:

how do u think bats feel?

Bats actually have the most sophisticated radar systems based on sonar, using frequency sweeps. They probably feel quite comfortable ...

[/quote] yep,, those comfortable bats

reax · Post by **reax** » Tue Dec 12, 2006 12:17 am

I actually found the Live 6 manual entry for Compressor II to be one of the clearest descriptions I've read on how compressors work.

That said, I'm still endlessly confused by compressors, and find myself still dependent on presets for any results. Like others have said, it's not like I haven't read 100x on what they are and how they work. But it just still doesn't compute.

I think because dynamics are so tough to visualize, and perhaps one of the less obvious and immediate aspects of sound design. Modifying pitch or time is obvious and easy to visualize. Not so much with dynamics and transients.

abletonian · Post by **abletonian** » Tue Dec 12, 2006 3:44 am

you dont have to understand life to live do you?
(dont tell me that you anderstand life)
stwist da knobs till it sounds good to you.

-art- · Post by **-art-** » Tue Dec 12, 2006 4:30 am

I think the confusing thing is a lot of people say *compress the fuck out of and it will sound fat* so people just start chucking compressors on everything and wonder why it sounds shit. Sure compressors can be used to achieve some neat effects, sucking punching, but in the end its a problem solving tool. In this day and age everything is compressed to the shit, big blocky waveforms with no dynamic range at all. People aren't using it just to solve the problems of dynamics within a recording, they're using them more like limiters and just boosting the overall signal. If you get everything working sweet in the tracking or mix phase, compressors will just be little light touches you use to add emphasis and clarity here and there. In electronic music sidechain compression is useful to let other things breathe while some event jumps out front, as you would probably hear about this with a kik and bassline, however if you mix and eq your bass and kiks right then they should be able to sit fine without competing against each other. Its like you have crap singers and shitty drummers, their levels are all over the place. So you lunge for the compressor. Its either one of two things that need improving, the performer, or your ears.

My 2c.

astroid · Post by **astroid** » Tue Dec 12, 2006 4:42 am

i got my mind blown when i gave a couple tracks to my buddy john to master-i hadn't compressed anything, but was quite careful in mixing. it came back and just sounded great, "radio ready", punchy, clean, beautiful. i asked what kind of compression he had used and he said "none". just eq.