Compressor attack

[il7mago]

Hi,

when sidechaining, is there any advantage to having a long attack time?

Usually, you want the attack to be for example 10 ms so you still hear the bass drum. But when sidechaining, the source isn't affected, so I tend to set the attack to minimum 0.01 ms. I'm I right to do so?

Secondly. If you had a release of 100 ms and you increase the attack by 20ms, do you then need to set the release to 80 ms?

[Forge.]

you usually want a fast (short) attack time when side-chaining to the kick so it responds to that initial peak - which is ultimately where you are wanting to duck the bass/etc the most

as far as release goes - use your ears for that one - how soon do you want it to return to normal? try setting everything to extreme settings (including low threshold and high-ish ratio) so you can hear what it's doing, then dial it back when you have it where you want it.

[il7mago]

Thanks Forge. I pretty much know what it does and how it works. I'm just a little confused as to what's the process behind attack and release. Does it follow an AR curve (as in ADSR without D and S), therefore release time begins when attack ends, or does it begin when attack begins?
Also, I'm not sure what the difference between FF1 and FF2 is. They say it's different models from Compressor I and Compressor II, but I wasn't around at that time. Are they modelled after real pieces of hardware, if so, which ones?

Appreciate your input!

[Forge.]

attack is how long it takes for the compressor to start working when the signal goes over the threshold, release is how long it takes to stop compressing after the signal goes back under - that's it really

you can adjust the curve with "knee" so it's smoother

FF1 etc - short answer, FF = Feed forward - FF1 was the first one they had in Live, then they improved it and added FF2 and FB (feed back) - you'd probably be better off googling what they mean, but FF is the more modern one, while FB is older but many still like the sound

in this sidechaining example though you might find FF1 is less likely to cause any clicking

[il7mago]

For me knowing how the release works is crucial. Say have a 110 bpm song and I want the release to be exaclty 1/8 bar. Thats roughly 272 ms. Now if I have an attack of 10 ms, I want to know if I leave the release at 272 or if I change it to 262.

I thought FB was the feedback model (which doesn't allow for sidechaining by the way.) FF1 and FF2 are both feed forward. There's no documentation on what the difference is between these.

[Forge.]

I think you are maybe over-thinking it.

you should have no problem getting it sounding right using your ears. That's why I said turn everything else up while you get the settings right. beyond that I'm not really sure what you are asking? Why would you need to be that precise?

[il7mago]

I do listen and often change it accordingly, but it saves time when changing the tempo of the song to know by what ratio you should change all your compressor's releases for example, rather than starting over.

Oh and I'm merely curious about that stuff. It interests me to know. Too bad I couldn't get a straight answer yet.

[Forge.]

.. Too bad I couldn't get a straight answer yet.

?? what 'straight answer' are you not getting? I answered all your questions????

[ze2be]

Hey il7mago. I know what you mean, it frustrates me a bit too. Id love to have a "hold" on the compressors envelope, like every where else. A full adsr with a total time display of some sorts. My work around is to set up a track with simpler, and give it a long, static noise sample. Full sustain, short release. Feed midi from the kick to this track, and further send this signal to the ducking compressor. You now get a perfect signal to duck from. Now you can set the compressor to a very low release, and use the kicks midi notes to set the length of the ducking effect. The brilliance of this is that it will scale perfect if you change the tempo.

[Mage2k]

For me knowing how the release works is crucial. Say have a 110 bpm song and I want the release to be exaclty 1/8 bar. Thats roughly 272 ms. Now if I have an attack of 10 ms, I want to know if I leave the release at 272 or if I change it to 262.

I get what you're talking about but that's just not really how it works. The release time doesn't have any relationship to the attack. The release time is from when the signal goes below the threshold. The attack is from when it goes above the threshold. So, setting the attack is fairly easy for things like side-chaining to a kick since you know that it crosses the threshold pretty much right at the start of the sound. When it goes back below the threshold is entirely dependent on the kick's amplitude over time, not the bpm of the track. So, if you want it to pump on 1/8 of a bar start with 272ms and adjust from there with your ears.

[il7mago]

For me knowing how the release works is crucial. Say have a 110 bpm song and I want the release to be exaclty 1/8 bar. Thats roughly 272 ms. Now if I have an attack of 10 ms, I want to know if I leave the release at 272 or if I change it to 262.

I get what you're talking about but that's just not really how it works. The release time doesn't have any relationship to the attack. The release time is from when the signal goes below the threshold. The attack is from when it goes above the threshold. So, setting the attack is fairly easy for things like side-chaining to a kick since you know that it crosses the threshold pretty much right at the start of the sound. When it goes back below the threshold is entirely dependent on the kick's amplitude over time, not the bpm of the track. So, if you want it to pump on 1/8 of a bar start with 272ms and adjust from there with your ears.

Right, except when you set a high threshold, it doesn't matter how the kick evolves over time as the only relevant part to the compressor is the initial impulse not the tail.

[mharris]

yes, but however you look at it, you'll never know the exact moment the level drops below the threshold. Therefore, making the numbers pretty much meaningless.

I think I understand what you're trying to get at.. Does the compressor always complete the attack phase before starting the release, or will it abandon the attack and start releasing as soon as the level drops below threshold.

I would be interested in knowing the answer to this if anyone would like to provide some info.

[ze2be]

If the input volume does not reach the treshold, the compressor will do nothing. When it hits the treshold, attack begins, and "hold" will follow the soundwave until it drops below treshold again. At this point release begins.

Got it?

[mharris]

Got it?

Nope, because you didn't explain the scenario that I asked about.

We all know what a compressor does and what attack and release are, the question is more about the specifics of how they interact together.
What happens when the level drops below the threshold before the attack duration has elapsed.?

[H20nly]

^

What happens when the level drops below the threshold before the attack duration has elapsed.?