I turn to tapeop for these questions.

http://messageboard.tapeop.com/viewtopic.php?t=8564

Ashley and Symettrix make good, inexpensive compressors which would be suitable on a live buss. These are not very 'colorful', and are really adept at controlling a sound without timbral smashing. I use a symetrix 501. You can buy one cheap(watch the tapeop board) and if you don't like it, sell it, they are pretty popular little things.

JoeMeek, RNC, ... These are more colorful, and that doesn't seem to be what you want. The BBE sonic maximizer in a multiband-fixed compressor that everyone and thier mother uses to get that dance-club sound, if that is what you are into.

Hey silvawhale, thx a lot for your advice. I know that the compressor market is very crowded and that each type of device will colour your sound, which of course also helps in creating a sound. For the moment I'm using the freeware audiodamage roughrider (just the default preset) and jeroen breebaert's freeware brickwall limitter. I really love the sound of the compressor when I drive things real hard they will start fighting each other which can cause padz to only get partially through (probably on the frequencies which the rythmic stuff leaves open)... I'm aware that i should be trying many different devices to find what i like, but currently i was looking at the art pro vla II (since this is a stereo compressor in my budgetrange).

i work as a soundman (both studio and live) and here's some thoughts...

if you do gigs without your own soundman, it's always a good idea to output as "final" sound as possible. also, if the compression is done at the house mixer, it may not be present at the stage monitors. by compressing the signal on stage, you always know what you hear.

the "good compressor"-debate could go on for pages. maybe the first important question is what KIND of compression are you looking for? what software plugin were you using?

if you're looking for multiband/maximizer-type of effect, there's much fever options in the hardware world. the hardware ultramaximizer, tc.electronics finalizer and the old-skool device i can't remember the name of..

I like to play a little gig so now and then with my pd setup running on a motu896 interface. To make sure everything pumps but doesn't clip, i now stick a vst compressor and a limitter at the end of my audio chain before going to the interface. However these things together seem to eat up quite some cpu (around 20%) which i like to use on my actual setup. So I was wondering if it's worth investing in some hardware devices for this setup?

I've read quite some reviews of some (hardware) compressors but I honestly wouldn't know which one would be suitable for what I'm trying to do. Further I've found no article on the use of compression except when it's about recording analog sources (what I'm not doing here). So i was wondering if it's common for other live electronica musicians to use compression on the signal they're feeding to the PA or is this more something you should leave up to the mixing boys and girls?

I don't know all the details of what makes an analog compressor sound analog, but here is the chapter on amplitude corrections (limiters and compressors) from Johannes Kreidler's Pd book. I find that the limiter patch is a better place to start if you want to make the regular kind of compressor.

And for analog saturation sounds, waveshaping works quite nicely -- take a look at hardoff's volume-leveling patch (I like using tabread4~ instead of tabread~ for less artifacts). You can also try cubic soft clipping and other types of nonlinear distortion.

Works pretty well. A while back I made a nonlinear compressor (saturator) external for pd. It uses polynomial functions to generate the nonlinear component.

http://puredata.info/Members/saturno/saturator-non-linear-compressor

Like a compressor time is also a variable

[sgn~] is just a sign function. I've never been able to figure out Roman's compressor, but if you want to learn about simple limiters and compressors in Pd, try the ones from Johannes' pd-tutorial.com. I personally prefer using his limiter patch to make a classic compressor with makeup gain.

this is part of the "unauthorised" abstractions

heres the compressor your looking for

copy it to the extras folder i pure data

http://www.pdpatchrepo.info/hurleur/compressor~.dll

This might be relevant to the discussion.

I made a nonlinear compressor external using polynomial functions. It's over at puredata.info

http://puredata.info/Members/saturno/saturator-non-linear-compressor
http://puredata.info/Members/saturno/saturator.zip/view

S

Your logic may be a little cloudy here. Let's review two things:

A linear system introduces no distortion. If the instantaneous amplitude of the signal input is A and the instantaneous output is B then A=B for all values.

You can view the process as B = f(A). The f is some function that produces B as a result of A.

A non-distorting (linear) effect can be gain, a simple multiply, in which case the function f is a constant, like B = 0.5A to halve the amplitude.

A non-linear system distorts the signal. [clip~] is a non-linear function which clamps B at some level for all A above and below a value. So is [abs~], which changes the sign of negative A values.

A compressor is not an instantaneous function. It changes the average level of B in accordance with the average level of A, yet it preserves the linear instantaneous releationship.

What you seem to be describing is an effect that behaves as a linear compressor up to a threshold, and beyond that it behaves as a distortion.

There are a few ways to go about it, but none can be done as a single flow. You need to introduce a side chain. That means splitting off the signal and performing some averaging/low pass filtering (maybe using [env~]), and then applying the result of that to a linear gain stage. Finally you introduce a separate distortion stage such that once the input passes a threshold some clipped signal results (regardless of the compressor stage).

I hope I have understood your goals.