Compression myths debunked, from UBK audio.
OK, “Top 4 Compressor Myths” DEBUNKED, Episode 1.
Today I’ll start with MYTH #1:
1) Attack is the time it takes a compressor to start compressing after the signal crosses the threshold.
This is arguably the most common understanding of what a compressor’s Attack is, it shows up in articles, forums, even books written by people claiming authority.
Shocking news: it could not be more incorrect! If you think about it for a second, that definition would mean that a compressor’s attack time is no more than a glorified delay control, presumably inserted between the input and the detector. I can promise you this: the only analog compressors I know of with a delay line anywhere in the signal path are those with ‘lookahead’ capabilities, but those have the delay line in between the input and output, so the detector is 'ahead’ of the signal and able to catch peaks 'before’ they happen.
And with that, here is the correct definition of Attack:
Attack is the time it takes a compressor to
A) apply 9dB of Gain Reduction on a signal, which it does
whenever a signal is over threshold *and* increasing in gain
As such, Attack isn’t so much a 'time’ as it is a 'rate’; increasing the attack time doesn’t slow down how long it takes the compressor to respond, it literally slows down the rate at which a compressor applies gain reduction. So it responds instantly, but it 'moves’ slower.
Think of it this way: imagine you’re at a red light with your foot on the accelerator. When that light turns green (signal goes over threshold) you hit the accelerator immediately, always, every time. But with a fast attack, you slam on the pedal and get up to speed quickly. With a slow attack, you press the pedal gently, so it takes you longer to get up to full speed.
In both scenarios, your response time is identical, you start moving as soon as the light turns green. The myth says that increasing the attack means you will wait longer to hit the pedal. The truth is that increasing the attack means you press down lighter on the pedal.
I could keep writing, but at this point it might be more interesting to see if anyone has any questions I can answer.
So ask away, and if not, I’ll continue writing later today or tomorrow and dig deeper into these myths!
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