Define compression release

[BFunk]

I have heard release defined two ways:

1. The amount of time the compression stays active after the signal crosses the threshhold
2. The amount of time the compression stays active after the signal drops below the threshhold.

Which is correct?

[falconspatriots]

Originally Posted by BFunk

I have heard release defined two ways:

1. The amount of time the compression stays active after the signal crosses the threshhold
2. The amount of time the compression stays active after the signal drops below the threshhold.

Which is correct?

BOTH!!!

[enjoi1018]

Originally Posted by BFunk

The amount of time the compression stays active.

Just shortened your definitions a bit!

[scottfeldstein]

Originally Posted by BFunk

I have heard release defined two ways:

1. The amount of time the compression stays active after the signal crosses the threshhold
2. The amount of time the compression stays active after the signal drops below the threshhold.

Which is correct?

#1 is correct.

[DeltaPhoenix]

The release I get from throwing a compression pedal across a room.

[cheapbasslovin]

From this article:

Release time is the time the compressor uses to return to unity gain after the input signal has fallen below threshold.

[scottfeldstein]

From this article:

Release controls how long it takes to "let up" and stop compressing after it's triggered.

[BFunk]

Thus my confusion. Ultimately, it does not matter in most cases. I just use my ears. I always thought it was #1. I remember reading #2 somewhere worth reading recently, but I cannot remember where.

[3506string]

I'm pretty sure it's #2

If the signal is above the threshold it will be compressed until it drops below the threshold.

[scottfeldstein]

Originally Posted by 3506string

I'm pretty sure it's #2

If the signal is above the threshold it will be compressed until it drops below the threshold.

This can't be true. When I set my comp for a slow release, I can watch the metering LEDs trail off slowly--even well after I've stopped playing any note at all. Clearly the Release knob is operating on a timer from when my signal crossed the threshold and has nothing to do with when it dropped below it.

[3506string]

If you've stopped playing, wouldn't that mean that the signal has dropped below the threshold?

If you set the threshold low enough to catch 100% of the input signal, the compressor will not stop compressing no matter what the release is set to.

[bongomania]

Originally Posted by scottfeldstein

This can't be true. When I set my comp for a slow release, I can watch the metering LEDs trail off slowly--even well after I've stopped playing any note at all. Clearly the Release knob is operating on a timer from when my signal crossed the threshold and has nothing to do with when it dropped below it.

Actually, just because the LEDs are still acting "well after you've stopped playing a note" does not mean what you have interpreted it to mean. What it actually means is the release time is so slow that it is still in progress some time after you've stopped playing. It really is the case that the release depends on when the compressor is no longer being triggered, i.e. the signal is no longer over the threshold.

Now, there may be some circuit designs where the release time starts at the moment the threshold is first crossed, but it would be nearly impossible to tell the difference, because it would be continually retriggered for the entire duration of signal over the threshold. Comps do not generally have any logic inside them that says "trigger once and then do not trigger again until there has been a lapse of input signal".

[bongomania]

Hopefully that explains why my definition (#2) is almost identical to #1 in reality.

[scottfeldstein]

Originally Posted by bongomania

Actually, just because the LEDs are still acting "well after you've stopped playing a note" does not mean what you have interpreted it to mean. What it actually means is the release time is so slow that it is still in progress some time after you've stopped playing.

But that is exactly what I am interpreting it to mean. My volume is still being lowered, even though my signal isn't...well isn't anything. From a practical standpoint, sure: the actual volume of my rig isn't being changed. It's zero. But the volume knob inside the comp is still lower than it was before I started. Thus, the release is going off when the threshold was reached, not when it stopped being reached.

But since you're disagreeing with me, clearly I am misunderstanding something important...

[bongomania]

The compression is constantly triggered every moment the signal is over the threshold. The instant the signal is not over the threshold, the compression starts to wind down. The amount of time it takes to wind down is the release time.

Again, there is nothing in the description of the LEDs fading out in their own time that indicates release beginning at the moment of the first trigger.

[SLaPiNFuNK]

The release time is the amount of time it takes for the gain reduction (compression) to stop once the threshold is passed.

If you hit your open E string and its dynamic level triggers the compressor (reaches the threshold) the gain is reduced by the amount determined in your ratio setting. The amount of time until the compression ratio is reached is determined by the attack time. If you have a fast attack, the compression ratio / gain reduction is realized faster, if slower attack it will take longer for the compression (full gain reduction) to kick in. The release is then triggered when the source audio falls below the threshold, the release time determines how long the gain reduction takes to no longer occur.

[testing1two]

Originally Posted by SLaPiNFuNK

The release is then triggered when the source audio falls below the threshold, the release time determines how long the gain reduction takes to no longer occur.

bingo

[chuck3]

Originally Posted by SLaPiNFuNK

The release is then triggered when the source audio falls below the threshold, the release time determines how long the gain reduction takes to no longer occur.

If the source audio has fallen below the threshold, why doesn't the gain reduction just stop immediately? (Probably a stupid question, but I don't know the answer.)

[SLaPiNFuNK]

Originally Posted by chuck3

If the source audio has fallen below the threshold, why doesn't the gain reduction just stop immediately? (Probably a stupid question, but I don't know the answer.)

It will if you have a very very short release time.

If there was no release time you would and could experience of Pop, same with a very short attack time.

Not to mention also experiencing a potential drastic quick increase in level depending on what your gain reduction setting is.

[scottfeldstein]

Originally Posted by bongomania

The compression is constantly triggered every moment the signal is over the threshold. The instant the signal is not over the threshold, the compression starts to wind down. The amount of time it takes to wind down is the release time.

That makes sense.