Confused about compression

[TambourineFiend]

Hello there. I recently tried to start using compression, and I'm a confused about a couple things.

My main problem is I don't understand how the compressor's definition of "decibels" relates to my track's decibel meters. That was horribly worded, but here is an extreme example to illustrate: In the compressor, i put the threshold to -30 db, and the ratio to 100:1, or infinity. By setting the ration to 100:1, i'd expect the compressor to act as a limiter and then prevent the signal from getting any higher than -30db. Still, when i look at my track meter, the signal is still rising above -30db, even getting as high as -16db at times... What's up with that? Could it be that my track's meter is not in decibals(though i'm pretty sure it is...)? I'm using Sonar 4 by the way.

Any ideas/help would be greatly appreciated, thank you everyone.

 

[bubbagump]

Are you using a hardware or software compressor? Also, explain the signal chain. The reason I ask is because unless you clibrate everything, 0db may be slightly different from unit to unit... especially if you are using a combination of -10 and +4 gear. However, if this is a plugin, then we have something else to look at. If it is softawre, my guess is that you are using the compressor as an insert effect POST FADER. What that means is that the track really is putting out what the meter says it is. However, seeing that you have the compressor post fader rather than PRE fader (which is usually where you want your compressor to be) the meter doesn't "know" about the effects of the compressor and can't meter accordingly.

 

[TambourineFiend]

Hmm yes, I'm using a software compressor, and I guess I am using it as a post fader because I am simply inserting the compressor into in the "fx bin" of my track. But what is the difference between a pre and post fader, and how do i make the compressor effect be pre fader? Thanks for your help, Bubbagump

 

[TuoKaerf]

Pre fader means that the compressor occurs before the signal hits the fader, so it is independant of any level changes done on the fader.

Post fader means it is after the channel fader in the signal path, and any fader moves will effect what happens with the compressor.

 

[bubbagump]

I don't know how to switch pre and post as I am not a Sonar guy. Anyone know their way around Sonar?

 

[Albertm]

I have Sonar 5 and always wondered this. I am not home right now but just had an idea. Can't you load compressor it as an instrument. Like you would a dx or vst soft synth somehow. I will try when I get back. Tambourinefiend, This would be a good question to post in Cakewalk forum.

 

[XLR]

In the compressor, i put the threshold to -30 db, and the ratio to 100:1, or infinity. By setting the ration to 100:1, i'd expect the compressor to act as a limiter and then prevent the signal from getting any higher than -30db. Still, when i look at my track meter, the signal is still rising above -30db, even getting as high as -16db at times... What's up with that?

It depends on the attack and release settings also - mainly the attack. For instance if the attack is set to 20 ms, every time the compressor releases and re-engages any transient peaks during the first 20 ms will get through.

Tim

 

[giraffe]

i've been goofing off with this crap for about 6 years, and i'm still confused about compression.

 

[TambourineFiend]

Albertm, I figured out one way to make the compressor pre-fader.

Just go to the track which you want to be compressed, and send it to a bus. Then load the compression effect on the bus. Then, you go back to your original track and choose PRE(I think the default is POST, but you just click it and it turns to PRE). Then just turn on the send effect by clicking the button next to the PRE button(it turns green after you click it) and you are in business.