Tips and Tricks: Ducking
Markus here! Today we’ll be looking at one of my favorite techniques:
It’s in almost every mix on any track with percussion at this point. Most easily heard in EDM, ducking (often somewhat incorrectly referred to as sidechaining) is a common and easy-to-create technique used to make kicks (and sometimes other percussion) seem louder and more aggressive. We use this a lot in our patches, and we get asked how it’s done quite a bit, so here’s a quick tutorial on a few ways to achieve this useful mixing technique.
Technique 1: The Classic
This is probably the easiest, least efficient, best sounding way to achieve sidechain ducking: using an actual compressor. That’s where this whole thing started: run a signal through a compressor, route your kick drum to the sidechain input, crank down the threshold, crank up the ratio and BAM, you’re ducking.
There’s a little bit more to it in Eurorack, though, especially if you want to duck multiple sources. If you read my post on Mixing for Modular, you know I like bussing things around a lot with multiple mixers. Generally, the easiest way to duck a bunch of signals with a compressor is to mix them together, run them through the compressor, then run the output of your compressor to your master mix with all your other stuff. I did it that way for a very long time and it worked great. The sidechain input can either be your kick drum (just split it using a mult) or, depending on the compressor, you may just be able to use your trigger signal. I like doing this because I can make the kick sound like whatever I want it to without it affecting how the ducking sounds.
Technique 2: VCAs and envelopes
VCAs change the volume of things. So why not just use some of these? This is my personal favorite technique and is what you’ll hear in my Instagram clips. I currently use the WMD Performance Mixer which has CV inputs for the level of each channel, but if your mixer doesn’t you can just use any VCA. The envelope I use is Pons Asinorum. It has ramp mode, which is perfect for this: when it’s not triggered, it holds at +5v, meaning it should open a VCA enough to let signal through at roughly full volume (although check the manual for your VCA for voltage specs to make sure this works for yours), but when it receives a trigger it drops down to 0v and then ramps back up, creating ducking. I simply mult the trigger from my kick to PA’s trigger in and route its four outputs to four channels in my mixer (I generally use four channels for percussion and four channels for melodic content I want to duck). Since I’m using separate channels on the PA for each mixer channel, it gives me even more control: higher frequency content doesn’t need to duck for very long, but lower frequency content often sounds best when it ducks out of the way for a little longer. I can tailor each envelope length to exactly what I want it to be.
What if I don’t have a PA though?
You should. But if you don’t yet, all you need is a decay envelope, an offset, and a signal inverter. Roti Pola offers both of these things: channel 1 has a +5v offset, and any other channel can invert an envelope. There are plenty of other module combinations that can create this sort of inverted/offset behavior as well. In fact, the ever-popular Make Noise Maths can offset/invert one of its own envelopes, if you have one of those lying around.
Want a quick demo? This post from our Instagram page uses the envelope method described above (and also shows off the mellower side of the upcoming CIP).
Ducking is cool! And it’s a useful technique. For techno/house/DnB/what have you it can be super helpful to add clarity to a patch, even if you do no other mixing. But if you want to learn more about mixing… Check out Mixing for Modular Part 1 and Part 2, and our post all about compressors!