Studio One’s Autofilter has a sidechain, which is a good thing—because you can get some really tight, funky sounds by feeding a drum track’s send into the Autofilter’s sidechain. Then, use the Autofilter’s sidechain to modulate a track’s audio in time with the beat. Funky guitar, anyone?
But (there’s always a “but,” or there wouldn’t be a Friday Tip of the Week!), although this is a cool effect, a real wah pedal doesn’t start instantly in the toe-down position before sliding back to the heel-down position. Your foot moves the pedal forward, then back, and it takes a finite amount of time to do both.
The “decay-only” nature of autofilters in general is certainly useful with drums. After all, drums are a percussive instrument, and a percussive filter sweep is usually what you want. But the other day I was working on a song, and really wanted an attack/decay filter effect that was more like a real wah pedal—where the filter moved up to the peak, before moving back down again. Here’s the result.
On the Autofilter, ctrl+click on the LFO sliders to zero them out, so that the LFO isn’t adding its own signal (although of course, you can do that if you want—the 16 Step option is particularly useful if you do). The screen shot gives a good idea of a typical initial setting.
The dark blue track is the guitar, and the green track, the drum part. I often cut up tracks are that modulating other tracks, and Track 3—a copy of the main drum track—is no exception. This track’s pre-fader send goes to the Autofilter’s sidechain input. The track’s channel fader is down, so that the audio doesn’t go through the mixer. We’re using this track only to provide a signal to the Autofilter’s sidechain.
Track 2 is a reversed version of the drum part. It also has a pre-fader send that goes to the Autofilter sidechain (conveniently, you don’t need to bus signals together to send signals from multiple tracks into a Studio One effect’s sidechain). Like Track 3, the track’s channel fader is down, so that the audio doesn’t go through the mixer
The end result is that the reversed drums provide an attack time that sweeps the filter up, while the forward drums provide a decay that sweeps the filter down. So is the sound more animated than using only the forward drum part? Listen to the audio example, and decide for yourself. The first section uses the forward trigger only, while the second section adds in the attack trigger—the effect is particularly noticeable toward the end.