Practical Applications For Using Dynamic Sidechains

[thehitman]

Hi, I wrote this up to hopefully give people a better understanding of a valuable tool that often gets ignored; dynamic sidechains. There’s many great practical uses for them. I apologize if I am repeating information that has already been presented on this site, but I think this is something worth sharing to those who aren’t familiar with what they do, and what uses they can have.

Firstly, let me first try to explain what a side chain is. Basic dynamics processing is based around adjusting the amplitude (volume) of a sound in a certain manner (up or down) by a certain amount once the amplitude reaches a certain level (threshold). Most dynamics processors allow for an external signal to be used as the trigger (to reach threshold). So in other words, you can use any sound you want to trigger when the dynamics processor changes the level. Since it’s only for triggering, the processing is not done to the signal being sent to the side chain. In fact we don’t actually hear the signal going to the side chain at all. It’s the signal that is going into the main input of the *FX that is adjusted in volume. Simple analogy: the guy behind you in line is pushing you into me, but I only see you bumping into me when he pushes you.

 (*Anywhere I use the term FX, I'm talking the reverb or delay)

 So how is this useful? I’m glad you kept reading because it’s very useful in a lot of ways.

A. Ducking FX:
    We don’t want our FX to clutter the mix. Delays can run over everything. Reverb can crowd a part and make it sound far away. But we like FX, and we want FX. We can always automate them to respond in just the parts we want them. But another easy solution is by ducking the FX. What this means is, when the sound that is being sent to the fx is actually happening, the fx are lowered in level. When the sound stops happening, the level returns to normal and therefore is heard in the spaces between the parts. This can prevent FX from obscuring the performance. You don’t want a sea of FX ruining your good performance, but you do want FX. assuming we are using our FX on an aux return, add a compressor AFTER the FX on the aux fader (not your vocal track). use a prefader send (set to unity is fine) to the key input of the compressor from the vocal track and a post fader send to feed the input of the FX to adjust the amount that’s on the vocal when it’s not happening. So the vocal is triggering the compressor to turn down (duck) the FX when it’s happening and letting the FX trail off naturally at the ends of words when there is space that the vocal isn’t happening. It’s important to use a prefader send going to the key input so that you can ride the main vocal fader without affecting the ducking of the FX. This isn’t as complicated as it sounds, and it’s worth trying. you’ll probably fall in love with it.

B. Tightening Parts Together:
    Lets say you have 10 singers. You record them all on separate tracks. 3 of the singers didn’t rehearse enough and they had poor timing with the others. Sometimes they came in too early, sometimes they ended too late. These things can be adjusted manually by shifting parts, and that would be the best way to line them up, however, lets say the client doesn’t have the money or the time to sit there while you shift around the beginnings and ends of some of the vocals. Besides that, the song is 15 minutes long. Well, it’s not the ideal fix, but by putting an expander or gate on the suspect vocal tracks and using a (prefader) send from a vocal track that has all the timings right to trigger the gate on the external side chain can remove all the early entrances, and cut short late endings in real time. It’s a quick fix, maybe not the best fix, but you might not even be doing final vocals, you might be doing reference vocals and there’s no reason to spend so much time on something that is just going to get redone later. So this can be a helpful way to tighten things up.

C. Accenting The Groove:
     Ahh yes, bass and drums. You always want them to be tight together. Maybe you want to emphasize their tightness to make the groove come out a little more. Well, by putting an expander on the bass and triggering it from a kick and snare via the external side chain can elevate the hits where they hit together.  so even if the performance is spot on, you can enhance it even more.

D. Volume Level Priority Of A Sound In The Mix:
     Ok, so you got a really big sound on the vocals in the chorus of your song. It’s stacked with 16 vocals (4 different notes x 4 tracks). Wonderful, but for the verses you only have a single lead or a lead and 1 or 2 backgrounds. The verses overlap with the chorus in the beginning and end of the verses and the huge sound of the chorus just overwhelms the verse vocal to the point you can barely hear the words. There’s a limited amount of headroom in the mix, and you are very happy with the overall level of both the chorus and verse, so you don’t want to turn down the chorus and turning up the verse in those parts might not sound consistent with the rest of the verse. Well, (Captain Hindsight..Errr, I mean) side chain to the rescue! Just output all the chorus vocals to a stereo aux fader and put a compressor on it. Then use a prefader send to send the verse vocal to the external key input of the side chain so that the compressor only affects the chorus vocals when the verse overlaps the chorus. This will allow the verse vocal to still be in front of the chorus vocal without turning up the verse and without having to turn down the chorus vocals during the overlap. Problem solved and nobody got hurt.

E. Auto Talkback:
     This is my personal favorite. It’s so elegant and easy and slick. Are you sick of having to hit the talkback switch every time you want to talk to the artist in the booth? Let’s make it easy with side chains! Before you start recording, set up an aux fader in the session and input your control room talkback microphone to that fader. (Any microphone in the control room will do). Put a limiter on the talkback channel and pull the threshold all the way down so that it turns the sound down all the way (when it’s triggered). Now, you can use 1 of either of these things. You can use a prefader send from the tracks you already have or make a new track and put a small audio clip of a sine wave or noise (from the signal generator) that outputs ONLY to the key input of the limiter. If you use an audio clip, (which will work best) make sure the audio clip runs the entire length of the song. (Loop it) If you use the backing tracks, then the only thing that could be a problem is in spots where the background tracks aren’t happening. Once everything is set up the result being, whenever you press play, the limiter mutes the talkback. Whenever you are not playing, the talkback mic is wide open and you no longer have to push the talkback button. Cool, huh?

F. Cleaner Snare/Kick/Toms Gate Triggering:
    When we use gates on drums, there’s sometimes just enough bleed from other drums to trigger the gate. This can be a real annoying problem. You can use the side chain path through filters or an EQ to get more accurate triggering, but let me also give you another way. Duplicate the snare track. Output the duplicate track directly to the side chain key input on the gate. Then proceed to cut apart the duplicate snare track to remove the noise. Strip Silence in Pro Tools is a quick way to do this. Now, normally that would sound awful because of the track stopping and starting abruptly, but we don’t actually hear that track. We hear the track that wasn’t cut up. The gate is triggered by the cut up track where you removed the bleed. Its also good to nudge the duplicate a millisecond earlier in the song so that it triggers the gate just before the snare transient. That way you don’t lose any of the attack on the snare when the gate opens. So, the bleed doesn’t trigger the gate and the gate can be set to open and close at a speed that feels natural.

 G. Fattening Up A Weak Kick:
    This is a weapon of last resort. The kick drum that you are working with doesn’t have any bottom to it. You can’t boost the bottom on something that doesn’t exist. So, we have to add low frequency to the kick. Here’s a method how you can do that. Create an aux track and put a signal generator or oscillator on the track. Set it to sine wave and choose a low frequency like 50-60 hz. The sine wave is continuous so you need it to only happen during the kick hits. Put a gate after the signal generator and use a prefader send from the kick track to trigger the opening and closing of the gate. You will have to adjust the attack and release controls to get it to blend in more naturally, but it is possible to get it right on point with the kick. So, now you have added low frequency that is “in” the kick.

See how useful dynamic side chains  can be? There’s also so much more that can be done. I hope these ideas help people in developing their own uses and inspire creativity.

Thanks for reading. I’m happy to answer questions and provide visual and audio examples of these things in usage.

[Flash Harry]

These are fantastic tips. Thanks for sharing them.

[hooper]

Best article I've ever read on side-chain compression and have printed out to keep with my pile of reference stuff.

Thanks for posting!

[Geir]

I'm a long way from actually using these tips, but I sure do appreciate them as they broaden my knowledge of what's possible and also starts me thinking of what to have in mind when using my simple tools and recording techniques so that I avoid some of the "problems" that side-chaining can fix!!

Thank you for sharing !!

[Hook]

I'm a long way from actually using these tips, but I sure do appreciate them as they broaden my knowledge of what's possible and also starts me thinking of what to have in mind when using my simple tools and recording techniques so that I avoid some of the "problems" that side-chaining can fix!!

Thank you for sharing !!

+1
I write, record, mix , master & on to the next one; usually in my car. Someday I can hope to hire you to care about this for me.
I know however some here will get a lot out if this, my brain hurts. Must find my ukulele.
Rock on!

[thehitman]

using dynamic sidechains is the sort of thing that once u figure it out 1 time, you'll get it. it's much simpler than what it sounds like. i used 7 examples that are fairly common things for everyone from beginner to intermediate to pro.

i know it's something i wouldn't have used or attempted to use if i didn't know when they could be useful. i feel like this is something that helps out enormously in getting a better sound, yet most people aren't even thinking about it. i'd be surprised if there wasn't at least 1 of those issues that everyone hasn't run into at some point. if so, what did you do about it? these kind of problems can seem shackling at times. never fear, there's a tool for the job in the toolbox.

i hope this genuinely helps. please don't be afraid to at least experiment with it. once u do, you'll be better for it.

[AndyR]

Fantastic stuff. I was aware of this technique, but the way I record at the moment (straight into a BR1600, mix and master on there, only use the BR effects) means I can't really take advantage of it...

But you've reminded me about it and explained it really well - and that's another mark on my "why don't you go back to using a DAW?" list

Many thanks

[thehitman]

thank you AndyR for your kind comments.

u might like the BR1600 for songwriting and tracking, but at some point it might be worth dumping your songs to a DAW for mixing. so long as you don't mind the extra work. it may be worth it though.

[bruno]

Fantastically interesting piece - and insight into home v pro - and a logical capability available from technology. I'd never really thought about this before. I not sure how I feel about it - similar to when my brother (in the profession) told me that most studio engineers used drum mikes to trigger their favourite drum samples rather than use the audio. In the end, it creates a great sounding end product - but I do wonder if this strips out some of the human feel (I make no judgement on this, I find this really interesting).

As Andy says - this is the DAW vs. dedicated machine argument (well for me). My whole set up is built for speed - to start recording and minimising setup time. The BR1600 is simple to use, the Kemper is simply brilliant to dial in great guitar and bass sounds, beta monkey drum loops - well some studio engineer and session player has done all  the hard work for me. That's the pieces of my personal puzzle. However the journey never ends. Technology holds no fear for me - I've spent a lifetime coding and designing solutions - but I still prefer using the Br1600 for me personally - despite having a Mac - as I know I'd end up down the rabbit hole endlessly refining. I guess its a question of knowing when that end point is and the end product is good enough. I sure when one day I'm able to have more time, I will spend time on a DAW :-) but its a really, really interesting insight - many, many thanks for posting this.

B

[thehitman]

thanks bruno.

both DAWs and dedicated hardware are great at what they do. i would never try to argue that one is universally better than the other. there's very good reasons to use one or the other depending on what you are doing and what your end goal is. i exclusively use DAWs for doing studio work as an engineer and as a producer. i have in the past used dedicated recorders for songwriting and tracking. i've also had a number of clients bring me tracks from a dedicated unit to import into a DAW. i have a lot of love for dedicated units and i have to say that they can sound fantastic. it would be great to have both as they both excel at certain things that may be inefficient for the other.

think about all the great music you've listened to that was made before DAWs and digital recording was used. there's no argument that can be made for any digital format being the best when at the end of the day, it's about the music and if you can use your tools effectively to get the best out of the music, you've chosen wisely.