beginners compression question (short and sweet)

[ungar]

ive new to it, but i been reading lotta stuff, i dont need broad overview on what it is or anything, i just have to make sure of two things

1.) initially, when the signal breaks the threshhold, compression is only limiting
the peaks, not simultaneously raising the quiet parts, this only occurs when
you do the additional gain increasing (ie, lowest part of sound was -3db, raise
gain up 2, now lowest its -1db) so now the quiet parts have been raised...

but that part is up to the user its not auto like the peak reduction is, correct?

2.) the release parameter, in most non technical terms is what? i know the attack
is how long after threshold is broken before the sound gets compressed
(according to ratio), i can grasp that. but release means what, how long the
compression effect will last for? shouldnt the compressor automatically work
for as long as it sees the input signal is above threshold?

when i set my release to very very very fast, does this mean that as soon as a peak breaks threshold, the compression will start and end so fast that i can barely tell? also, i been reading that if u set it too long, it will not recover in time for the next peak, i dont understand how this is a problem because isnt the compressor not effecting the audio under the threshold anyway?

like, if my thresh is 5db, and ratio will drop anything over by 2db, if i leave my release on too long, will sounds that were previously 3db and below thresh still be effected and now these will be 1db? is that what they're talking about,

woops, i kinda blabbed too much, anyway i really appreciate any help thanxx

[Fredrik]

1) Some compressors/limiters will have a automatic makeup gain and when you turn the threshold the apparent volume will rise, (for example the L1 limiter if you adjust the two faders simultaniously). Also found in some oldschool limiters for example where you raise the volume on the input and pushing the signal towards a cieling. Most of the times though its up to the user to adjust this, personally I think that if its apparent loudness that you are trying to achive it is easier to evalute the effect if you set the peaklevel to be the same in bypass as in operational mode.

2) a fast release means that the compressor will go out of compression as soon as the signal is below the threshold, sometimes this will be audiable and sound as though you were riding the fader up and down this effect can often be reduced by setting the releasetime longer witch will give a smoother sound.

If you set the releasetime to be so long that the next peak will arive before the compressor has recovered this will have the effect of not really using all the shown
gainreduction as compression. For example if your meter tells you that you have
5db of gain reduction then in this scenario when the peak is no longer present and the compressor goes out of action the meter might just be able to reach (say 2db) on the meter, now this means that you actually only has 3db of gain reduction, the other 2 db´s has the same effect as to turn down the output 2db.

[lucey]

you're good

release, in musical times, is the time it takes to let the compression sound go away

technically, you have it. the time after the level goes past the threshold for the compression to get back to no compression.

if it happens too fast or slow, it's too obvious. or maybe you want it obvious?!


attack and release effect rhythm as well as being a dynamics processor, so the release can move the singal in time, ahead or behind the groove ... on a kick, snare, bass ... etc. With a vocal the rhythm is always changing so different times, and different boxes suited to vocal, make more music sense.

a slow release on a snare that's on the downbeat of a bar (only) will draw the release out longer, making it sound fatter. if it's too long it will effct the next snares attack by not grabbing in the same way, because the compression is still 'on' as that next snare hits.

so if there are more snares, say on 1 and 2 of 4 ... then you will get a different sound from the snare on the 1, than the snare on the 2 with a long release



just play with a kick or snare, attack and release at one ratio ... that will show you best

with a snare, cutoff of the transient as much as possible with fast attack, then slow it until you dont cut it off at all. an optical limter may not grab fast enough, a vca can get ahead of the attack and really mess with it!

play with a fast release that sounds more neutral and then a slow one for a fatter sound that will be getting in the way of the next transient


spin those knobs and listen, it's always different and the interplay is the main thing. all the knobs change everything so just listen to what you like.

[JonCraig]

alan p. kefauver's book, "the audio recording handbook" is a great beginners book. behold kefauver's diagrams:

--jon

[ungar]

thanks, to all of you for explaining, now i think i get it, one last thing, anyone know of a software compressor that shows the level of gain reduction? right now im using battery only to do drums to learn, but it doesnt show anything like that. just atck rel ratio thresh, thanxxx

[Fredrik]

The waves c1 and renissance compressors will show the amount of gainreduction
also the psp compressors, and a freeware, the fishfillets blockfish wich can be downloaded for free here.

http://digitalfishphones.com/main.php?item=2&subItem=5