FabFilter

Trying to get my head around the variable look ahead feature on the Pro C2.

Would this variable look ahead be sort of the same as the Feed Foward/Feed Backward on hardware comps?

I don't know of a hardware compressor with lookahead, although there probably are some. It's like splitting the signal, and sending one side into the side chain input, and the other side into a delay line with a few ms of delay, then into the signal input. This means that the envelope detection circuit gets to "listen" to the sound just a little before it has to do anything, which helps it deal with transients.

thanks chris - perfect explanation i now understand look ahead

so back to the feed forward/feed backward - this is not possible on the pro c2? or is FF/FB being used "under the covers" in some of the compression styles?

Hi,

Pro-C uses a feed-backward compression topology in the Classic style. All other compression styles use feed-forward. This is independent of lookahead though.

Cheers,

I'm confused (and very disappointed) by the latency Pro-C 2 reports to the host when enabling Lookahead. It's always 20ms (in Studio One), no matter what. What's the point of the Lookahead slider then?

Ain't that slider supposed to be something like 112dB Big Blue Compressor's Look Ahead knob? That one dictates the latency reported to the host too. So the time you choose it's the latency introduced. Want 2ms of lookahead? Got 2ms latency. Want 3.3ms of lookahead? Got 3.3ms latency. Perfect.

So what's up with Pro-C 2 behavior?

Big Blue Compressor's Look Ahead knob is stepped, so you probably won't get the values I entered above, but my point remains.

Hi e@ars,

Interesting questions about lookahead vs. latency. We've chosen to fixate the latency at 20 ms (when Lookahead is enabled). This makes it possible to automate the lookahead in your host, and it makes it much easier to find a proper value for the lookahead setting.

The problem with dynamic latency changes, is that it's the responsibility of the host to react to them, and different hosts do this in different ways. For example, Cubas might update its latency compensation while playing, but Logic Pro X only updates it after a stop/play...

Cheers,

Wow, I would have never thought of someone wanting to automate the lookahead of a compressor...

What scenario would request lookahead automation?

Well?

How about controlling material that has increasingly harsh transients whilst keeping the overall envelope settings the same