Opto Compressor question!

[Caine123]

i played with some (standard) compressors with the typical settings AR, threshold etc. but i like somehow the OPTO comp for my master but i cannot really get specific results, e.g. i want all signals reaching -12 dB compressed at a ratio about 2-3 and normally i set my threshold then to about -12 dB. but here i have no threshold, so how do i know i hit the -12 dB with the opto?

[sinkmusic]

Others may correct me if i'm wrong, but opto compressors, by their design, works as "leveling *amplifiers*", which means that instead of lowering the threshold, you should increase the input gain.
It's all about gain staging (as "opto" means that such compressors uses vactrol devices, which reacts more with stronger input signals), it's a rather standard topology with such devices (at least in the hardware world, cf LA2A) : maybe try with a +12dB input gain, to see if you get in the same ballpark as with a -12 threshold ?
I hope that helps

[Googly Smythe]

You could also try using that big "Compression" knob. And don't forget to switch the meter to "GR" mode.

[Caine123]

thanks mates, sry this pic is taken online not from me ;D, the compression knob doesnt get further than 10

[BDeep]

thanks mates, sry this pic is taken online not from me ;D, the compression knob doesnt get further than 10

That's likely because it's a scale, not dB. Just use your ears and level meters before and after (oh and I'm sure the GR meter in the plugin will tell a thing or two )

[ImNotDedYet]

Get out of the habit of I do this at this level and take off this much and just use your ears to see what sounds best.

VU meter is likely scaled at +4db where when you're hitting 0, you're actually at digital -18db. If you want to hit digital -12db, you want the inputs higher than 0 I'm guessing, but it doesn't appear to have much of a reading past 0. You could always turn the compression knob to 0, output to 0 or standard or whatever and see what your DAW meters are reading. When they're at -12, you're good to go.

But beware, because there are some plugs that emulate hardware that work best when the incoming signal is -18db (0db in the analog world) or at least the signal that it's processing is at that level. (Klanghelm's SDDR is like that) Not sure about the TRacks Opto - even though I own it. I've never actually used it.

[Caine123]

thanks again so much mate but let's not go by ear atm , here you see the spikes at -4.8 dB.
normally i would set my comp at about -4.5 dB with a ratio of 3:1 and it should get let spikey. (if im correct).
but with an opto comp i dunno how to get to the -4.5 dB?

[BDeep]

If you want the spikes out, why don't you use a limiter? Limiters chop those right off, so then there's a one on one relation with the 4,5 dB spikes you see and the 4,5dB threshold.
A comp with a 1:2 ratio setting for instance, and a threshold of 4,5, will give you a 2,25dB gain reduction.

But as I suggested earlier, the GR meter on the plugin tells you the amount of gain reduction... why don't you just look at that? Set it such that it hoovers around your desired 4,5dB

[Caine123]

If you want the spikes out, why don't you use a limiter? Limiters chop those right off, so then there's a one on one relation with the 4,5 dB spikes you see and the 4,5dB threshold.
A comp with a 1:2 ratio setting for instance, and a threshold of 4,5, will give you a 2,25dB gain reduction.

But as I suggested earlier, the GR meter on the plugin tells you the amount of gain reduction... why don't you just look at that? Set it such that it hoovers around your desired 4,5dB

thanks man, the prob is i dunno what to use to get more GR. if i turn the compress knob it gets more GR, but also if i turn the Input button. so either more compress or more input?

[djscorb]

Why not simply use a compressor that you are more familiar with at first, that has more predictable and standard threshold controls etc. Get the amount of reduction you want and then a/b between that and your opto comp and dial the opto in by ear until it sounds better than the other comp.

Don't get so hung up on the numbers, it has nothing to do with the music or the sound.

In a comp with more standard controls, setting a threshold of -4.5 when there are peaks only up to -4.8 will do almost nothing, a ratio of 3:1 will knock off just one tenth of a dB! You would be unlikely to hear a difference!

If you are using that setting on another compressor that gives you more GR than that then it is probably due to a soft knee, which means you are using that compressor by ear anyway, as the threshold tells you very little about how deep it is grabbing.

Hope that helps

Scorb

[dave dove]

http://us.focusrite.com/answerbase/what ... ompression

dave