Producer & synthesist Klayton, aka Celldweller shared this video demo that explores the 4ms Spectral Multiband Resonator Eurorack module.

The Spectral Multiband Resonator is a resonant filter module that can be used for classic filter bank work, but also can be used to make plucked/struck sounds, to vocode, to harmonize, to output spectral data, to quantize audio to scales and more.

The video is part of a new Celldweller/Vintage King video series that focuses on hardware/gear walkthroughs.

The 4MS Spectral Multiband Resonator 

At first glance, the SMR works like a normal six-band graphic EQ: six frequency band-pass filters are mixed together using sliders. Resonance/Q is variable, which changes the “ringy-ness” or width of the bands.

But here’s where comparison stops.

The frequency of each channel is treated like a note in a scale, and the six bands form a chord. Spin the Rotate knob and the “notes” circle around the scale, rotating back to the bottom once they’ve reached the top. Adjust Spread and the distance (interval) between each note changes. Triggers for up/down motion, CV inputs for sequencing and scale selection allow for flexible control with external modules. Morph, which automatically cross-fades between frequencies, together with variable Slew allows rhythmic clocks drive the SMR as a variable-speed evolving resonant filter.

At maximum Resonance/Q, the SMR can be struck like a gong or marimba by inputting clocks or triggers. The frequency of each channel is quantized to a scale: beautiful chords, ethereal tones and eerie ambiance flows easily. With lower resonance, the SMR can pull out particular frequency bands, and sweep these across the spectrum.

Two 1V/octave Frequency jacks allow for tracking even and/or odd bands and creating floating melodies over evolving chord bases, or complex percussive membrane sounds.

Features:

• Six filter channels, selected from twenty active filters displayed on the light ring
• Variable “Q” (Resonance) ranges from classic band-pass to ultra-resonant ringing
• Ring of 20 full-color lights displays the filter frequencies
• Filter frequencies move about the scale using Rotation and Spread
• Rotation “spins” the frequencies around the scale
• Spread controls the gap between neighboring bands
• Morph creates a variable speed cross-fade when the filter frequencies change
• Lock buttons prevent each channel from changing in frequency (resonance can also be locked)
• Freq Nudge knobs for creating de-tuning effects, or honing in on an exact frequency
• Frequency CV input (1V/octave) for even and odd bands (flip switch selects single or multiple channel control)
• Stereo ins and outs stagger the bands into evens/odds for an immersive stereo field
• Spectral content outputs for each channel (Env Out) allow for vocoding (spectral transfer)
• Fast or Slow tracking speeds for Envelope CV ouptuts, or selectable Trigger output mode is useful for extracting a beat from music
• Sliders and CV jacks control each filter’s level
• Slew switch applies slew-limiting to the CV level jacks, which prevents clicking from clocks or triggers
• Each bank has 11 scales of 20 frequencies/notes each.
• User-programmable scales (select octave, chromatic note, and microtonal adjustments for each note in the scale)
• Scale banks for Western, Indian, Chromatic, Micro-tonal, Equal tempered, Just intonation tunings
• Rotation/Spread moves about an entire bank, or can be limited to a single scale
• White noise is normalized to the inputs, so the SMR can be used without an external signal

Advanced features

• Program your own scale. The frequency of each of the 20 notes can be assigned by setting the octave, the semi-tone, and coarse and fine micro-tone. Up to 11 scales can be saved permanently in the user bank
• Adjust color scheme of the LEDs. Pick a pre-programmed color scheme or create your own using the sliders to set Red/Green/Blue values. Custom color schemes can be saved permanently
• Save your settings in one of six parameter banks. Note position, scale and bank selection, Q value, Lock settings and color scheme can be saved and recalled on the fly. On startup, the SMR loads settings from the last saved bank.
• Optional alternative filter type for a more exponential decay when plucked and different timbral qualities. Freq jacks no longer track 1V/oct in this mode.
• Slider LEDs can be assigned to display level for each channel (combination of slider position and CV on the jack), or clipping for each channel.

Pricing and Availability

The 4MS Spectral Multiband Resonator is available for US $475. Details are available via the 4ms site.