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Posted by Ian Vanderson on Jul-12-2004 15:07:

How does a compressor work?

My Question ist:

How does a compressor work and what makes the difference between the Reason Compressor Unit and any 500 Dollar compressor on the market.

Looking at the Reason Compressor, I understand it as far as the Attack value reflects the time elapsing, until the compression takes effect. And the Release value "quotes" the time, how long compression should take effect, after the signal is falling down under the treshold.

But what ist the treshold related to? To the amplitude? So halfway treshold means all signals louder then treshold and anti clockwise treshold means, that the whole source signal will be affected? And how about the ratio thing? How will a signal above the treshold be squeezed? Can't imagine, that a ratio of 20:1 reduces the signal so, that there remains only 5% of its volume.

I'm asking all this, because I've spend the whole last night on trying to cut a low frequency peak by 1-5 compressors, but this d*mn f**king peak wouldn't disappear or at least get smaller...

Posted by hey cheggy on Jul-12-2004 15:29:

The threshold is generaly measured in dB. You set the threshold depending on the amplitude of the waveform you are trying to compress. I you set the threshold above the peak of the wave, then the compressor will no do anything.

It will only compress the signal that goes over the threshold, so the overall volume will not drop by the ratio, just the signal above that volume.

Posted by CrackedLcd on Jul-12-2004 15:56:

Click Here
and Here

Posted by Ian Vanderson on Jul-12-2004 15:57:

Thank you cheggy!

But I'm still wondering, why this compressor yesterday didn't cut this certain peak. If reduced treshold more and more until halfway. The track was exported as a wave file, where the volume faders are as close as possible to the treshold, where the track starts to clip. So why did this compressing no effect by putting the Attack and Release values to 0?

Posted by DeZmA on Jul-12-2004 18:17:

there was a good thread some time ago with extensive feedback of dj thy (he knows all about sound theory). Just do some search

Posted by nova2wl on Jul-12-2004 19:05:

are you using the compressor in reason? because i have always had trouble with the compressor in reason not functioning correctly

Posted by Vizay on Jul-12-2004 20:07:

a compressor is basicly a tool that gives you the ability to manipulate the dynamics in a sound. in other words the diference between the peaks and the lows if I'm not misstaken

the ratio decides how much the sound will be compressed (2:1 or 3:1 etc)

the threshold is what tells the compressor when it should start compress and it's meazured in db just like someone said (although in reason it's not meazured in db for some reason )

so basicly, if you set a compressor to:
ratio - 2:1
thres. - 15

it means that the compressor will start it's work when the signal goes over -15db and it will be compressed two times it's regular state

feel free to correct me if I'm wrong on anything as I'm no real expert on the subject

Posted by MaxC on Jul-12-2004 23:22:

quote:
Originally posted by Ian Vanderson But I'm still wondering, why this compressor yesterday didn't cut this certain peak. If reduced treshold more and more until halfway. The track was exported as a wave file, where the volume faders are as close as possible to the treshold, where the track starts to clip. So why did this compressing no effect by putting the Attack and Release values to 0?

Does reason have a built in limiter? You might want to try putting a limiter on the offending track to get rid of those unwanted peaks.

Posted by rb2k1 on Jul-13-2004 12:04:

compression tutorial (basic beginners guide)

~Ross B

Posted by Ian Vanderson on Jul-13-2004 15:17:

Thank you, guys.

I think, I've understood the last subtleties of the compressor after that great article on ww.ethanwiner.com .

quote:
Originally posted by Vizay
... and it will be compressed two times it's regular state.

And this was the point, I concern most. The signal won't be compressed relatively to its regular state. It is only the part above the treshold, that will be compressed. Just a subtlety, but important to know.

And yes, it was the Reason (2.5) Compressor Unit, that I used. I'm still wondering, if Reason takes the whole availible volume range as basic for the treshold range or only the volume range of the current signal. However, don't know why, but somehow this Reason Compressor device doesn't seem to be the "only truth".

Hope to get some better results by using Waves Gold or TRex.