Sidechains on Compressors

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tyler657recpro

tyler657recpro

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What exactly is a sidechain? What I thought it was is a tip/send ring/return insert thing so you can just plug in a 3 cond. cable into that, and into an insert on your board. I tried this with my Alesis 3630 Compressor, (which I got 4 free, so no loss 4 me), and it didn't seem to work. I made sure everything matched up, as far as wiring goes, so I want to know if that's what it's really for. Or is it just Alesis?
 
Sidechains are for triggering the compressor circuit with a signal OTHER than the one being sent in through its inputs....

Like for ducking narration over music - you send the music through the compressor, and you run a copy of your vocal narration thru the sidechain - the compressor then triggers from the vocal signal, not the music...... and if you set the comp settings appropriately, you will get the music automatically being turned down whenever the narrator speaks.....
 
You can also use the sidechain as in and out of a parametric EQ, dialing in the frequency of sibilants and peaking them, so they are more compressed than the rest of the signal. That's called de-essing. If you play with that same signal chain and the settings on the comp, you can also use it to boost just one particular frequency by CUTTING that freq in the EQ, in order to beef up something that's kind of wimpy in the track, although that application is probably bordering more on mastering than mixing... Steve
 
so it is basically an insert for the eq, but not to plug in an insert from the board?
 
Yep. Good example, mighty Blue one.

Here's another use of sidechain to create a de-esser:

Mult your vocal track to a second fader (or copy to another track if you are on a DAW). On the 2nd track, find the frequencies (high ones!) that most exagerate the "ssss" - boost those, and cut the rest.

Now send that EQ'd signal into the side chain of your compressor. The compressor will trigger only when it gets that "ssss" sound, giving the same result as if you were able to quickly manually drop the fader on every "sss", but more accurately and with a lot less work!

The important proviso here, is make sure you are NOT accidently also sending that sidechain source track into the main mix!

Now, Tyler, see how much more you can learn here if you don't pretend you already know everything?
 
Argggh! No fair!

While I was typing my answer Steve beat me to the post!!! :mad:

And Tyler chimed in with a question that is so far from what anyone had just explained, I'm not even sure I understand his question!!!:eek:
 
Tyler, what the sidechain is, is a place to break into the compressor's inner circuitry, and either modify the response of the compressor by changing the characteristics of the signal you're compressing (such as changing the EQ so the opposite effect will happen at the output, by that portion of the signal being affected more or less than other frequencies), OR, you can (as bear said) feed a totally different track/signal into the sidechain, causing the compressor to change the gain (level) of the MAIN input ONLY when there is signal coming into the sidechain connector. When you feed an announcer's vocal track into the sidechain and the music bed into the MAIN input, every time the announcer speaks the music is lowered in level, or "ducked" - the level you feed into the sidechain determines HOW MUCH the music level is reduced, along with the settings on the compressor itself. Now, lets see if the subject is even the same, or if there are 25 more posts to sort through... Steve
 
Sidechain

tyler657recpro said:
so it is basically an insert for the eq, but not to plug in an insert from the board?

Just to clarify, it's not really an "insert for the eq," though it's a little like that.

What you return at the sidechain doesn't go into the signal path, just into the "detector," i.e. it goes to the circuitry that triggers the compressor to compress.

Just to be repetitive, two obvious ways to use the sidechain: (i) take the sidechain output, process it, and send it back to the sidechain input, e.g. to make the compressor into a "de-esser" as discussed above or (ii) put something totally different into the sidechain input, e.g. to make the compressor into a "ducker" as also discussed above (you might want to make the bass "duck" in response to the kickdrum by running the bass through a compressor and feeding the kickdrum to the sidechain, or make background music duck in response to a voiceover by running the music through the compressor and feeding the voice to the sidechain).
 
hmm

Nobody mentioned Noise gating, with the side chain.... I used a noise gate filter on my bassline, and fed the drum beat into the sidechain, and set the frequencies to about 210hz, so i could make the low end less mudldled, and make the kick punchier.
 
tyler657recpro said:
Okay, I understand now!

Yo' tyler, I'm proud of you! After 117 posts you fin'ly asked a question with humility and and an earnest quest for knowledge!

I knew U could do it! Keep up the good work!
 
how bout sidechaing with the drums on a synth patch...or something like that?? you don't hear that much, but it's kinda dramatic.
 
hey, bear,
how would you send a copy of the vocals if you're already sending the whole mix through the inputs..?? explain this whole thing?? would you send the vocals also through the original mix?

T
 
You can take a mult (copy of the signal) from the patchbay for that track...

(Without a PB you'd need a Y-connector or something similar....)
This is another reason PBs wired in a classic multitrack configuration is very useful!

Bruce
 
I have an akai dps16.. nothing with cables for each track. would the aux. out for just that track work?? but what is this tip=send business?
 
tip=send is for inserts

You can use inserts, aux sends, direct outs - any output you can from your board to get a copy of the signal for the mult....

Worse case is the brute force method of using a Y-cable off the signal somewhere....
 
It's the little hole on your mixer that says "insert" right above it.

It allows you, with a tip/ring/sleeve plug (at least in lower cost mixers) to create an output to a processer and an input back into the board using just one hole and a Y cable.

Let me guess: your next post is going to ask "what's a tip/ring/sleeve" "what's an output" "what's a processer' "what's an input" "what's a hole" and/or "what's a Y cable". :rolleyes:
 
oh my, i'm not THAT dense! well..probably..yeah..I am.. but! does it insert, and go out thru the same cable!! heh..
 
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