A rotating speaker is an extremely complex signal processor (as most mechanical signal processors are—like plate reverbs). It combines phase shifts, Doppler shifts, positional changes, timbral variations, and more. And of course, Studio One includes the Rotor processor, which does a fine job of capturing the classic rotating speaker sound.
However, I’ve always felt that rotating speakers have a lot more potential as an effect than just emulating physical versions—hence this FX chain. By “deconstructing” the elements that make up the rotating speaker sound, you can customize it not only to tweak the rotating speaker effect to your liking, but to create useful variations that don’t necessarily relate to “the real thing.” What if you want a speed that’s between slow and fast? Or a subtler effect that works well with guitar? Or simulate the way that the horn spins faster when changing speeds because it has less inertia than the woofer? This FX chain provides a useful, more subtle variation on Rotor’s rotating speaker sound—check out the audio example—but the best way to take advantage of this week’s tip is to download the multipreset, roll up your sleeves, and start playing around.
Rotating speaker basics. There are two rotating speakers—one high-frequency driver, and one low-frequency drum. A crossover splits the signal to these two paths, so we’ll start the emulation by setting the Splitter to Frequency Split mode around 800 Hz. Here’s the routing.
The high-frequency and low-frequency paths each go into a Flanger to provide Doppler and phase shifts, and an X-Trem for subtle panning to provide the positional cues. Let’s look at the individual module settings.
The Analog Delay adds a 23 ms reflection for a bit of a room sound vibe, with some modulation to add a Doppler shift accent. Finally, an Open Air reverb (using the 480 Hall from Medium Halls) creates a space for the rotating speaker.
Knob Control. This was the hardest part of the emulation, because changing speed has to alter (of course) Flanger speed, but also the Flanger’s LFO Width because you want less width at faster LFO speeds. The X-Trem speed and Analog Delay LFO speed also need to follow the range from slow to fast.
However, the curves for the control changes are quite challenging because the controls don’t all cover the same range. Fortunately you can “bend” curves in FX Chains, but you can’t have more than one node. As a result, I optimized the knob settings for the lowest and highest speeds—besides, a real rotating speaker switches to either speed, and “glides” between the two settings as it changes from one to the other. An additional subtlety is that the high-frequency “speaker” needs to rotate just a little faster than the low-frequency one. Also, they shouldn’t track each other exactly when going from the slowest to the fastest speed because with a physical rotating speaker, the low-frequency drum has more inertia.
All these curves do complicate editing any automation, because you need to write-enable each parameter when you turn the knob. So if you need to change some automation moves you made, I recommend not trying to edit each curve—just try another performance with the knob.
Oh, and don’t forget to try this on instruments other than organ!
I’ve always been fascinated with using one instrument to modulate another—like using a vocoder on guitar or pads, but with drums as the modulator instead of voice. This kind of processing is a natural for dance music, and using a noise gate’s sidechain to gate one instrument with another (e.g., bass gated by kick drum) is a common technique.
However, the sound of gating has always seemed somewhat abrupt to me, regardless of how I tweaked a gate’s attack, decay, threshold, and range parameters. I wanted something that felt a little more natural, a little less electro, and gave more flexibility. The answer is a bit off the wall, but try it—or at least listen to the audio example.
Setup requires copying the track you want to modulate (the middle track below), and then using the Mixtool to flip the copy’s audio 180 degrees out of phase (i.e., enable Invert Phase). This causes the audio from the original track and its copy to cancel. Then, insert a compressor in the copy, and feed its sidechain with a send from the track doing the modulating. In this case, it’s the drum track at the top.
When the compressor kicks in, it reduces the gain of the audio that’s out of phase, thus reducing the amount of cancellation. However, as you’ll hear in the example, the gain changes don’t have the same character as gating.
You can also take this technique further with automation. The screen shot shows automation that’s adjusting the compressor’s threshold; the lower the threshold, the less cancellation. Raising the threshold determines when the “gating” effect occurs. Also, it’s worth experimenting with the Auto and Adaptive modes for Attack and Release, as well as leaving them both turned off and setting their parameters manually.
Using a compressor for “gating” allows for flexibility that eluded me when adjusting a standard noise gate. If you want super-tight rhythmic sync between two instruments, this is an unusual—but useful—alternative to sidechain-based gating.
The day has arrived! Studio One 4 has been released and is available for purchase from your favorite dealer or shop.presonus.com! Version 4 adds a ton of new features (full list is available in a PDF linked below) but some of the things we’re really excited about include: