How do i use sidechain?

[proxy]

Traditionally, a compressor will react to the signal that is fed to it, and process the sound according to settings like attack, release and ratio.

Sidechain allows you to compress your signal based on a different sonic input. Common uses may be to feed a hi-passed version of your signal to the sidechain so that compression doesn't react to low-end info.

If you're using compressors for color (and not just dynamics/envelope alteration), it changes the "focus" of the compression. Very cool for bass, vocals and whatever else seems to need it.

You can use side-chain with a gate as well. If the signal is a pad, then you can feed something percussive (like drums) to the sidechain, and the gate will open on the percussive hits, letting the pad become a pulsating pad in the rhythm of the drums.

Perhaps other descriptions will be more useful, but I hope that's useful.

- proxy

[warhead]

It's a circuit which affects the overall character of a compressor, but doesn't enter the actual signal path itself. In other words, plug an EQ into the sidechain of a compressor and jack up 3k or so on a vocal track...while the compressor is set to a fairly effective ratio (3:1 or much higher even) you should hear the 3k being overly affected as it is causing the compressor to hit especially hard now that you've jacked the level of that freq band. The 3k to 7k range is typically where you'll find sibilance issues, and now you have de-essing capability!

Also, you could do the following:

Patch a kick drum track into a compressor, while running the bass guitar track through the actual comp's signal path. Jacking the kick drum's level into the sidechain, you can now affect the overall audio signal of the bass guitar by having the kick drum affect the compressor as well. You can set the attack very fast and release fast to medium, and allow the kick to pop out of the mix a bit more as it "ducks" the bass guitar signal's initial attack. Done right, it can be a great effect.

Side chain dynamics control is one of those things you miss greatly when mixing in the box.

War

[theblotted]

what about say if i have a song with bass and acoustic gtr. i like the low end on the acoustic when it's alone, but gets in the way when bass enters.

how do i use side chain so when bass enters, it only ducks the low end info of ac. gtr; while retaining that jangly metal string sound?

do i split the ac. gtr signal into 2, hi and lo, then use sidechain? cuz i'm working on a project and can desperately use this trick... but there're 6 ac. gtr tracks (all playing similar figures)...

there's gots to be a better way, no?

(it'd help if a device/plug is suggested... thx)

[Junkie]

split the bass into two signals, accentuate the frequencies you want to cut and cut the frequencies that you dont.
Remember to keep this signal out of the main mix, feed it into the sidechain/key input of the comp that is applied on the guitar then it is just a matter of getting the balance between the envelope and input of the comp.

[sheltersoton]

some plugs such as the uad fairchild have a side chain... how does this work?

[theblotted]

Originally Posted by Junkie

split the bass into two signals, accentuate the frequencies you want to cut and cut the frequencies that you dont.
Remember to keep this signal out of the main mix, feed it into the sidechain/key input of the comp that is applied on the guitar then it is just a matter of getting the balance between the envelope and input of the comp.

but wouldn't this simply compress the entire ac.gtr (all frequency of spectrum), rather than simply compressing certain parts of freq (of ac.gtr)?

i want to leave the hi's of ac.gtr untouched.. or sound untouched, anyway.

something like a multiband compressor with sidechain would make more sense...

[proxy]

You could send your acoustic(s) split to two AUXes, one that has the low end, and one that has the high. Blend and balance those two signals so that it covers the sonic ground you originally liked, then sidechain the low-info one off of the bass. Kind of DIY multi-band side-chaining.

But maybe side-chain isn't the right tool. Perhaps just automating a hi-pass to kick in on the acoustic(s) when the bass comes in is better.

I don't know of a multi-band comp with side-chain, although it would be cool.

- proxy

Originally Posted by theblotted

what about say if i have a song with bass and acoustic gtr. i like the low end on the acoustic when it's alone, but gets in the way when bass enters.

how do i use side chain so when bass enters, it only ducks the low end info of ac. gtr; while retaining that jangly metal string sound?

do i split the ac. gtr signal into 2, hi and lo, then use sidechain? cuz i'm working on a project and can desperately use this trick... but there're 6 ac. gtr tracks (all playing similar figures)...

there's gots to be a better way, no?

(it'd help if a device/plug is suggested... thx)

[Junkie]

Originally Posted by theblotted

but wouldn't this simply compress the entire ac.gtr (all frequency of spectrum), rather than simply compressing certain parts of freq (of ac.gtr)?

i want to leave the hi's of ac.gtr untouched.. or sound untouched, anyway.

something like a multiband compressor with sidechain would make more sense...

Nope, it will simply duck the relevant frequencies out of the acoustic guitar part whenever the bass notes are played, this what you were looking to do?

[arpodthegreat]

Thanks for the help guys. i was 75% there on understanding the "ducking" capability of a sidechain and now i get it. but here is my next question. when using an EQ in the sidechain

Originally Posted by warhead

In other words, plug an EQ into the sidechain of a compressor and jack up 3k or so on a vocal track...while the compressor is set to a fairly effective ratio (3:1 or much higher even) you should hear the 3k being overly affected as it is causing the compressor to hit especially hard now that you've jacked the level of that freq band. The 3k to 7k range is typically where you'll find sibilance issues, and now you have de-essing capability!

War

so do i just plug the EQ into the sidechain or do i have to have a duplicate of the vocal running through the EQ which is patched into the sidechain?

[theblotted]

Originally Posted by nathanvacha

No.

The thing is, it's the bass that will determine the compression on the guitar track. The sidechain is like having a hard wired remote control that acts as a feature that's not on the front of your comp. (or gate, or whatever...) It's like how you can't set the sleep timer on your t.v. unless you grab the remote to set it... but that controls when your t.v. is on and when it turns off. same thing. uh... sort of.

i understand the basic concept of sidechain, but your analogy just confused the hell outta me.

Originally Posted by proxy

You could send your acoustic(s) split to two AUXes, one that has the low end, and one that has the high.
But maybe side-chain isn't the right tool. Perhaps just automating a hi-pass to kick in on the acoustic(s) when the bass comes in is better.

this was what i wanted to avoid, but i guess it's do-able. thx.

Originally Posted by Junkie

Nope, it will simply duck the relevant frequencies out of the acoustic guitar part whenever the bass notes are played, this what you were looking to do?

yeah, i'm only trying to compress the low-end of Ac.Gtr, so that just the low's decrease in volume, thereby not fighting frequency wise with the bass. but when bass is not played, the low-end of Ac.Gtr is not compressed, so sounds like an Ac.Gtr with both hi's and low's.

what i don't understand is if i put a compressor on an Ac.Gtr, and if side-chain input is what you described (a tailor-EQ'd bass); wouldn't that still compress the entire Ac.Gtr when EQ'd bass is played (as opposed to only applying compression at the low-end information of Ac.Gtr)?

as of now, the compressor on the Ac.Gtr is not a multi-band, it's still "all frequency compressing" compressor.

so, even if the compressor is acting due to the EQ'd bass, my guess is that this will also cause compression and affect the hi's of Ac.Gtr; thus lowering the entire volume of Ac.Gtr and possibly cause pumping or unnaturalness.

please correct me if i'm wrong about this. thx.



.

[Junkie]

Side chain input also is known as Key input, i.e. the key frequencies that are put into the compressor (remember we're copying the bass track and pumping up the low end to act as our key) will trigger the compression, but this will only compress those frequencies.
This is also how de-essing works.
So essentially it acts as a 1 band multi-band compressor. It will not compress the whole guitar track (what would be the point in that?), only those key frequencies.

For example, if you applied a compressor to a guitar track and put a sine wave, at 300Hz, into the key input of the compressor only frequencies around the 300Hz mark would be compressed and the rest of the track would not change in dynamics. the key input tells the compressor what frequencies to compress and will be triggered whenever the key signal is present. This is the difference between sidechaining and multiband compression - the compression will activate when the key signal is there i.e. when the bass notes sound in real time, and not be compressed throughout the track.
As for making it sound unnatural, as with all compression that is all down to the compression settings - you could make it sound unnatural, or you could make it subtle. Sidechaining doesn't sound unique from any other compression if thats what you mean.

Just one thing; if you're not sure about sidechaining, how do you know it is what you want to do to the guitar track? Sounds like it would work for your needs though.

[nathanvacha]

Originally Posted by theblotted

i understand the basic concept of sidechain, but your analogy just confused the hell outta me...

Cool man, ignore it. throw it out the window. in fact...

i'll just delete it. sorry to confuse. good thread though. bad example, good thread.thumbsup

[theblotted]

Originally Posted by Junkie

Just one thing; if you're not sure about sidechaining, how do you know it is what you want to do to the guitar track? Sounds like it would work for your needs though.

hey Junkie, that's a great explanation. thanks. some testing will be underway tonight.

i honestly didn't know that side-chain was also key-input. so i guess in essence a side-chained compressor becomes a "multi-band' per se, so @ compressor's output, frequencies of the side chian/key input are affected, but leaving rest of freq untouched; as opposed to *only* reacting in entirety from the side chain signal's frequency... correct?

btw, i meant unnatural as in all freq pumping rather than just the low's.

to answer your question, i know about de-essing stemming from side-chaining, and i've also used side-chain compression for drums vs. other inst (much akin to Jules tech.) which worked but not as a frequency dependent material tho.

there are a few ways to go about doing the Ac.Gtr thing i mentioned, and i just wanted some input regarding an easier way of working; which led to a better understanding of side-chain, i suppose. so gracias thumbsup

Originally Posted by nathanvacha

Cool man, ignore it. throw it out the window. in fact...
i'll just delete it. sorry to confuse. good thread though. bad example, good thread.thumbsup

it's all good in the 'hood man

[MarkRB]

Hey all,

Hey Junkie you sure about side chains only working on the frequencies you key in?

If they do Ive been using them wrong for 15 years or so. You may be thinking of a de-esser which still compresses the entire signal as does any side chain ive ever used.

Although a gate with a side chain that only gate certain freq's would be insane, not alot of use but fun nonetheless

[Junkie]

see what you mean about the terminology concerning noise gates....
Im quite sure that key input and sidechain input are the same things, although correct me if im wrong!!
perhaps its key input for comp and sidechain for noise gates?

MarkRB - how have you been using your sidechains? I didnt think it compressed the whole track - when we de-ess gain reduction doesnt happen until the key frequencies appear.

[MarkRB]

Hi Junkie,

Well I guess it depends how your key input is EQ'd and your threshold setting, the idea being you exagerate the problem freq's so the S's or what ever are massive spikes, these spikes exceed the threshold and in turn compress or effectively turn down your original track for the time of the "problem".

Thankfully I don't need to use 'em too often.

[Junkie]

Yeh, thats what I mean!