Moog Music’s Spectravox & Subharmonicon: Filter Bank Adventures Off the Beaten Path

The video opens with Moog Music combining two of their modern analog instruments—the Subharmonicon and Spectravox—to explore new realms of filter bank modulation. Rather than sticking to familiar subtractive synthesis, the focus here is on how these devices can be patched together to create something less predictable. By routing the Subharmonicon’s VCO1 into the Spectravox’s carrier input, the stage is set for a deep-dive into spectral manipulation, using all ten of Spectravox’s filters as a playground for sonic experimentation.

The video then explores a classic subtractive approach by turning down all Spectravox filter levels except for Filter 1. This effectively transforms the filter bank into a single lowpass filter, with the Spectral Shift control acting as a traditional cutoff knob. To add envelope-driven movement, the Subharmonicon’s VCF envelope is patched to Spectravox’s Shift input, allowing filter sweeps reminiscent of standard analog synth techniques.

However, things quickly veer into more experimental territory. Moog leverages the Subharmonicon’s sub-oscillators—each with independent division settings—to modulate the levels of individual Spectravox filters. By patching, for example, VCO2’s sub-oscillator 2 output to Filter 10’s level, the video demonstrates how unsynced subharmonic modulation can create evolving, off-kilter patterns. The result is a filter bank behaving less like a static EQ and more like a living, breathing spectral organism.

The final minutes of the video are a showcase of the sonic possibilities unlocked by this hybrid setup. With multiple modulation sources patched into the Spectravox’s filter levels, and envelopes shaping both amplitude and spectral content, the resulting soundscape is anything but static. The patch demonstrates how interference between sequencer-driven notes, drifting sub-oscillator modulations, and shifting filter frequencies can yield a constantly evolving spectrum.

Moog’s demonstration makes it clear that the combination of Subharmonicon and Spectravox is more than the sum of its parts. By embracing non-standard routing and letting modulation sources interact freely, the system pushes well beyond traditional synthesis. The result is a complex, animated sonic landscape—a testament to the creative potential lurking in even the most classic analog designs when patched with a bit of curiosity.