PC76 compressor attack times extremely short?

elijahlucian
Hey all. So I have been poking around with audio as I usually do, and I noticed that the pro channel PC76 compressor attack times are extremely short. at most 1.2 ms? wouldn't this kill every transient in the world? What is this useful for aside from maybe parallel compression?

I don't understand how a short attack would "kill every transient in the world." The shorter the attack, the less the effect on the transient.

Of course, you're right. My brain was thinking envelopes. I should probably not try to type in the middle of eating lunch 

I am curious about this as well and have wondered the same thing. That I why I use the bus compressor more often. However, a couple of thoughts come to mind.
 
1. The attack time doesn't necessarily mean the that full compression ratio is reached at this time. It is more of a slope. Think Xdb/attack time. That is it will change from no compression to Xdb of compression in the attack time which could be less that what would be applied if the attack time was say 0. So, depending on the design of the compressor the 'Xdb' could be smaller, say 3db/1.2ms, than a compressor designed with 10db/1.2ms.
 
2. A snare or acoustic guitar could have transient information within a millisecond or two but you would have to use your ears or analyze the effect of the compressor on the instrument to see how much it really does to it.
 
3. There are uses for a quick compressor is you are trying to level out the overall volume and not change the tone of the sound too much. A quick compressor would not let as many transients through and would compress the whole sound more evenly than one with a slow attack time. Of course threshold and release time play into this as well.
 
Just some thoughts.

To make up for my egregious carelessness in responding too reflexively, I thought I'd do some research. The hardware 1176LN attack times go from 20 microseconds to 800 microseconds, so I guess extending that to 1200 microseconds - while making the PC 76 not as much of an "emulation" - does give you a little more slack.
 
But also remember that with an 1176, the way you adjust compression is by slamming the input, so you're going to have a lot more signal being let through by that initial attack. I took a screen shot with 1.2 ms compression and a kick drum input signal of +3 dB or so (and the lowest possible ratio, 4:1); it's interesting. The top image is the compressed signal - note that it actually has a much more pronounced transient than the lower image, which is uncompressed. I think this is due to the input gain being left alone for 1.2 ms, so it gets a nice, big spike.
 

 

No, it's the other way round.

I know nothing about the real hardware - but 1176 plugins always have short attack times (as others have said).
Maybe the h/w (and of course the plugins) actually takes a little longer, than the .8ms or 1.2 ms that the "knob" says. Either that - or drums and things just sound good with these short attack times...

Sorry if this was already stated.
 
I thought the hardware 1176 had a fast attack already? Since they model the software as close the the hardware, the software would react the same.