Sound Design Workshop: One for the Rhodes

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In the world of virtual instruments, a physical-modeled electric piano is as close as you get to the real thing. The premier examples of this type of instrument are Applied Acoustics Systems (AAS) Lounge Lizard 3, AAS Electric in Ableton Live 7, and Apple Logic EVP-88. In a bow to authenticity, these models offer very little signal processing beyond standard effects such as phasing, flanging, tremolo, and reverb. Synthesizers, on the other hand, are loaded with signal processors, ranging from classics like enveloped multimode filters to more-arcane processes like frequency shifting, formant filtering, and waveshaping. Although that kind of processing takes you beyond the electric-piano paradigm, it yields sounds you won't be able to get from a synth or a modeled electric piano by itself.

Many synth plug-ins provide audio input as an alternative to one or more of their oscillators. Route your virtual electric piano into that, and the rest of the synth's signal path is at your disposal. For my examples, I used Lounge Lizard 3 and Native Instruments Absynth 4 in Ableton Live 7. The process varies only slightly with different synths and DAWs.

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FIG. 1: Absynth''s A channel processes Lounge Lizard 3 (via Osc A) with allpass and lowpass filters modulated by the envelopes at the bottom.

Plugging In

Like many other synth plug-ins, Absynth 4 comes in two flavors — effect and instrument — and depending on your DAW's routing options, you can use either one. Although not absolutely necessary, routing MIDI to Absynth enables a broader range of processing. If you insert the Absynth effects plug-in after your electric piano, you'll need to route MIDI from another track directly to the plug-in. If you insert the Absynth instrument on a MIDI track, you'll need to route audio from your electric piano to the plug-in. Live 7 offers both options, and I prefer to insert the Absynth effects plug-in after Lounge Lizard 3. If you choose not to route MIDI to Absynth, set Auto Trigger at the lower right of the Perform page to either Always On (simulates permanently holding a note) or Audio (uses an envelope follower to trigger Absynth's envelopes).

Fig. 1 shows an Absynth configuration for applying envelope-controlled filters. The stereo electric-piano signal is routed into the Osc A component, which then feeds an allpass filter for a phase-cancellation effect followed by a resonant lowpass filter. Absynth's Poly setting, found on the Perform page, is critical to the sound. A setting of 1 keeps the Sustain mode envelopes from retriggering until all notes have been released. When you play and hold a chord, the envelopes advance to their sustain breakpoint, and you can then play lines over the chord (see Web Clip 1). The patch is still polyphonic, however, because you're playing the electric piano.

Bass Shift

Frequency shifters are rare, and Absynth's is a great tool for sound shaping. For example, you can create a gritty keyboard bass by inserting a frequency shifter in each of the three channels (see Web Clip 2). That works best for monophonic parts but is also useful for consonant musical intervals (octaves and perfect fourths and fifths, for instance).

Start by activating the Osc and Mod 1 tab in each channel, setting the oscillators to stereo Audio In mode, setting each modulator's type to Freq Shift, and selecting Ratio in the Frequency pop-up menu. Set the first frequency shifter for a negative (minus sign) shift, with a ratio of 0.5; set the second for a positive shift, with the same ratio; and set the third for a positive shift, with a ratio of 1.5. These settings produce an octave shift down, a perfect fifth up, and a major tenth up. Use automation or route a mod wheel or an x-y controller to set the levels of channels B and C. For more grit and a phasing effect, try the waveshaper and the Pipe effect in Absynth's Master channel.

If you're an advocate of the happy-accident school of synth programming, browse Absynth's factory instrument presets and, when you find one you like, try switching one or more of its oscillators to Audio In mode (see Web Clip 3). If you want the results to remain roughly like an electric piano, look in the Mallet Instruments, Pianos/Keys, and Plucked Strings categories. Try the Vocal, Bowed Strings, and Soundscape categories to create layered sounds. Try Percussion presets for sequenced and single-hit patches.

Len Sasso is an associate editor of EM. For an earful, visit his Web site


Applied Acoustics Systems Lounge Lizard 3 physical-modeled electric piano virtual instrument

Native Instruments Absynth 4 virtual instrument with effects processing for external audio sources