How do i set up a side chain with an eq?

[quincyg]

I am interested in the practice of side chaining a 2 bus compressor in order to let my low in pass through undisturbed. i have read that you can feed an eq to the side chain to accomplish this. can someone explain this process? how is the eq patched in? how do i set the eq say for example if i want to allow 100hz to pass through the compressor untouched? what is the difference between a compressor with a side chain insert vs a side chain in? i am completely new to this operation.

thanks!

[Mark Warren]

Basically if you're processing your mix without the sidechain, the compressor is seeing the bass and it's triggering the compressor, usually creating unwanted pumping.

So basically you could first eq your mix and cut out the bass until the compressor is acting the way you want it, and you can do this with plug-in eq's or hardware eq's, etc.

Then this eq'd mix is the one you send to the sidechain, and you do that by mult'ing your main mix. So you could set up some sends on your master fader (not sure what you're using to play the mix) and on those sends you insert the eq to cut out all the bass, and then feed that to the sidechain input on your compressor.

When the sidechain is engaged the compressor is now acting on your main mix, but reacting to what is coming in the sidechain. Once you have it set up just keep manipulating the eq until the compressor is having the desired effect on your mix without pumping to the bass like it was before.

[quincyg]

thanks that pretty much makes sense. so it seems that the compressor is actually still compressing the whole mix, but will not be triggered by the low end...right? does this make a drastic difference in the amount of bottom that gets through? seems like the compressor would still squeeze the bottom, just triggered a little differen't.

[thethrillfactor]

Originally Posted by Mark Warren

Basically if you're processing your mix without the sidechain, the compressor is seeing the bass and it's triggering the compressor, usually creating unwanted pumping.

So basically you could first eq your mix and cut out the bass until the compressor is acting the way you want it, and you can do this with plug-in eq's or hardware eq's, etc.

Then this eq'd mix is the one you send to the sidechain, and you do that by mult'ing your main mix. So you could set up some sends on your master fader (not sure what you're using to play the mix) and on those sends you insert the eq to cut out all the bass, and then feed that to the sidechain input on your compressor.

When the sidechain is engaged the compressor is now acting on your main mix, but reacting to what is coming in the sidechain. Once you have it set up just keep manipulating the eq until the compressor is having the desired effect on your mix without pumping to the bass like it was before.

What????

[David Kulka]

I think it would be better to do this with outboard analog gear than "in the box". I'd do it with a crossover, set to 100 Hz. Use the crossover to split the audio before the compressor, route the HF through the compressor, then sum the output of the compressor with the LF using 2 faders. That would be a clean, accurate way to do it.

No matter what technique you use there are many things that can throw the LF/HF balance awry and you'll have to adjust the final balance carefully. It could be done by ear or Protools or metering, using music, tones, or pink/white noise. I would get everything flat and balanced with the compressors (1 or 2? stereo compression?) in bypass, THEN add compression and make up gain to the HF side.

A side chain insert consists of a side chain out and a side chain in. You are interrupting a portion of the audio signal, sending it via some output to a processor, doing something to it then bringing it back via an input and recombining it with the rest of the signal.

If this sounds overly complicated, sorry!

[quincyg]

Originally Posted by David Kulka

I think it would be better to do this with outboard analog gear than "in the box". I'd do it with a crossover, set to 100 Hz. Use the crossover to split the audio before the compressor, route the HF through the compressor, then sum the output of the compressor with the LF using 2 faders. That would be a clean, accurate way to do it.

No matter what technique you use there are many things that can throw the LF/HF balance awry and you'll have to adjust the final balance carefully. It could be done by ear or Protools or metering, using music, tones, or pink/white noise. I would get everything flat and balanced with the compressors (1 or 2? stereo compression?) in bypass, THEN add compression and make up gain to the HF side.

A side chain insert consists of a side chain out and a side chain in. You are interrupting a portion of the audio signal, sending it via some output to a processor, doing something to it then bringing it back via an input and recombining it with the rest of the signal.

If this sounds overly complicated, sorry!

yes, i am talking about outboard. david, you are suggesting an alternative to using the compressors side chain...correct? with your method what would you suggest for a crossover that would work for this. i suppose it would have to be a stereo crossover and would ultimately add an additional layer of color with its circuitry.

if the previous poster's method works, it seems much easier, but i would really like to get a concensus on what the common method is.

in terms of inserts, i understand what a channel insert does normally, but not sure what the purpose of an insert on a compressor would be as opposed to a straight input.

i have heard of compressors that have a selectable low pass filter built in. seems like that would be the best option for me if it were available for my compressors, but it aint.

[quincyg]

Originally Posted by thethrillfactor

What????

not sure how to interpret this. are you saying that method is wrong or that you are confused by the statement.

[Fletcher]

Step one: Buy a Drawmer 1968

Step two: Insert in audio chain

Step three: Hit stereo switch

Step four: Hit "BIG" switch on left [master] channel

Step five: Tweeze to taste

Step six: Have a hit record

[GYang]

Originally Posted by Fletcher

Step one: Buy a Drawmer 1968

Step two: Insert in audio chain

Step three: Hit stereo switch

Step four: Hit "BIG" switch on left [master] channel

Step five: Tweeze to taste

Step six: Have a hit record

Although this doesn't explain what initial poster asked, using 1968 Big button resolves pretty much problems related to question.
Usually signal that goes to sidechain can be equalized to reduce part of low-end content what will, as result, change compressor's response on full range material.
Obviously, there are some alternative ways.

[quincyg]

thanks guys. got a clear answer over in the c1 c2 thread. i will check out the big button though.

[squeegybug]

I agree with thrillfactor.

What's so complicated? Connect a cable from the compressor's sidechain output to an equalizer's input. Connect another cable from the equalizers' output back to the compressor sidechain input.

If you want certain frequencies to not trigger compression, such as from bass or kick, just reduce those frequencies on the EQ. Now the compression element sees less of them, and doesn't do anything to the audio.

If you do want certain frequencies to trigger compression, for de-essing, etc. -- then boost those frequencies on the EQ. Now the element will see these first and react to them, reducing the gain when they appear. All the audio gets reduced, same as in a normal compressor without sidechain EQ. But if you set fast attack and release these reductions can go by without significant notice.

No audio goes through a sidechain circuit.

Steve

[Cornvalley]

Originally Posted by Fletcher

Step one: Buy a Drawmer 1968

Step two: Insert in audio chain

Step three: Hit stereo switch

Step four: Hit "BIG" switch on left [master] channel

Step five: Tweeze to taste

Step six: Have a hit record

That's why I got mine but step 6 is still troubling me. Whatcha got for that?