If you’ve made any sort of dance music in recent years, chances are very good that you’ve experimented with sidechain compression. For the uninitiated, this is a process by which you compress a signal very hard, but use a second signal (usually a 4 on the floor kick drum) to control when the compression kicks in. The result is a rhythmic “pumping” that can add a lot of excitement and energy to your track. Today, I want to discuss a slightly less conventional type of sidechain compression many of you may have heard in the music of artists like Benny Bennasi. In this case, we’ll be using the compressed signal as its own sidechain to create a pumping reverb. I’ll be creating this in Logic, but you should be able to adapt this technique to any decently-featured DAW.
1. Create an audio instrument track and call up your softsynth of choice. This technique is most commonly used on lead sounds, so go ahead and find a nice buzzy lead.
2. Record a short riff using this lead and quantize it.
3. On the mixer page, turn the knob of Bus 1 all the way up to 100%. Then, on Bus 1’s channel itself, change the OUTPUT assignment to “NO OUTPUT”. What we’re doing here is to send the original lead sound to a place where it can be selected as the sidechain source. So we don’t want to actually need to hear it on this bus, we’re just using it as a control signal.
4. Now, turn the knob up on Bus 2 to about 20-30% and on the Bus channel itself, insert an instance of your favorite reverb plug-in, followed by Logic’s compressor effect. The order of the effects is crucial here, as we want to pump the reverb signal itself.
5. On your reverb effect, call up a preset that’s of about medium length and is very bright and reflective.
6. Now for your compression settings. At the very top right of Logic’s compressor you’ll see a drop down menu marked “Side Chain”. This is where you select your side chain source. You should see Bus 1 as one of the available sources. Select it. Set the compressor’s RATIO to somewhere around 5:1, set your attack to around 10-15 ms and your release to around 50 ms. We want to compress this really hard, so set your COMPRESSOR THRESHOLD to a relatively low value giving you at least -20db of reduction.
If you’ve done everything correctly, when you play your lead, you should hear the lead coming through relatively dry until you release the key, at which point you’ll hear the compressor kick in and the level of the reverb suck “upwards”. Experiment with different lengths of reverb until you find something that is musically pleasing for the tempo of your track. If something this extreme sounding is not your cup of tea, keep in mind that with more subtle compressor settings, you can use this same technique to keep a reverbed lead line from sounding too muddy or indistinct.