Dynamics, Gating & Mixing · Audio effect
Bassops
Four-input sidechain ducker with optional harmonic stereo synthesis, bass phase widening and a ring-mod mode. A control signal (typically a kick-drum send) ducks the main stereo signal; the ducked result is summed to mono and the harmonics added by a waveshaper, high-passed at the cutoff, are decoded as a side signal that generates stereo width above it. The bass stays clean mono.
Opinion
Is very dependent on the kind of input signal. The stereo FX aren’t quite there yet, and the ducking envelope needs calibrating better.
Functionality
Bassops combines two processing stages into a single plugin:
Sidechain ducker — the signal on inputs 3 and 4 feeds an envelope follower whose output controls a VCA over the main signal on inputs 1 and 2. Attack and release shape how fast the duck opens and closes. Duck Depth sets the maximum gain reduction at full sidechain amplitude.
Mono split and stereo synthesis — after ducking, the stereo signal is summed to mono (a mono track that only feeds one main input is treated as dual mono, so it is not 6 dB down). The delayed full-range mono is the centre of both output channels.
- An optional waveshaper distorts the mono signal. The harmonics it adds, high-passed by a linear-phase FIR at the M/S Cutoff, become the stereo-difference component after M/S decoding, creating stereo width above the cutoff.
At Side Shape 0 % there is no side component, so both output channels are identical copies of the mono signal at unity gain. Increasing Side Shape progressively drives the shaper into saturation and hard-clipping, producing increasing stereo width above the cutoff. The bass is always the clean mono signal. The cutoff is soft at low settings (129 taps), so it sets where the added harmonics start rather than a sharp crossover.
A Wet control blends the processed signal against the latency-compensated dry stereo input. This is the only route to preserve the original stereo content of the source; the wet path uses a mono sum and does not retain the input’s stereo difference.
Bass 90° — an optional selector (Off / Left / Right, click the button in the Controls header). The bass below the M/S Cutoff is shifted 90° between the two channels at unchanged level, widening the low end; Left/Right chooses which channel is shifted. It uses a flat-magnitude allpass (Hilbert) pair, accurate across the bass range. Off by default, and when off it is not computed at all. With Wet below 100 % the bass partly decorrelates against the dry path.
Delay — two horizontal sliders under the vertical ones hold the main signal back so a bass note starts just after the kick instead of on top of it, another way to clear the bass from under a kick next to ducking it. Delay (beats) is locked to the host tempo and steps through fractions of a beat (Off, 1/64 … 1 beat); Delay (ms) is free, 0–200 ms. They add, the panel shows the total in ms, and the sidechain is not delayed. It is a plain time shift (no echo), applied before the ducker and the dry path, so Wet does not bypass it. Changes crossfade over 10 ms, and it is not reported to the host as latency, since moving the bass against the kick is the point.
Ring mod — set Attack and Release both to 0 (the bottom of their sliders) and the envelope follower is bypassed: the main signal is multiplied by the signed sidechain, so you hear sum and difference tones instead of ducking. Duck Depth blends it in (0 % = dry, 100 % = pure ring mod). If either control is above 0 it is the normal ducker. The right-hand panel title changes to “Ring mod” while this is active.
The right-hand panel shows four live meters — Input, Sidechain, Duck Gain, and Output — making the ducking action immediately visible.
Parameters
| Parameter | Range | Default | Notes |
|---|---|---|---|
| Duck Depth | 0–100 % | 80 % | 0 = bypass ducker; 100 = full silence on sidechain hit |
| Attack | 0–500 ms | 10 ms | Envelope follower rise time; 0 = instant (ring mod with Release 0) |
| Release | 0–2000 ms | 100 ms | Envelope follower fall time; 0 = instant (ring mod with Attack 0) |
| M/S Cutoff | 50–5000 Hz | 200 Hz | LP/HP crossover; typical 80–300 Hz |
| Side Shape | 0–100 % | 0 % | Distortion on the HP path; 0 = mono output, 100 = hard clip ×8 drive |
| Wet | 0–100 % | 100 % | Wet/dry blend; dry is latency-compensated original stereo |
| Bass 90° | Off/Left/Right | Off | 90° bass phase shift between channels; idle when Off |
| Delay (beats) | Off, 1/64 … 1 beat | Off | Main-input delay locked to the host tempo; adds to Delay (ms) |
| Delay (ms) | 0–200 ms | 0 ms | Main-input delay in milliseconds |
Routing
- Inputs 1–2 Main stereo signal to be processed.
- Inputs 3–4 Sidechain control signal (e.g. a dry kick-drum send).
- Outputs 1–2 Ducked, processed stereo output.
Use a dry kick send on inputs 3–4 rather than a processed bus. Applying heavy compression or limiting to the sidechain before it arrives will flatten the envelope follower’s response and reduce ducking clarity.
Latency
The FIR pair uses 128 taps (Hann-windowed sinc). This introduces 64 samples of latency, which is reported to the host so that automatic delay compensation keeps the track in time with other channels. The dry delay line matches this latency so wet and dry signals are time-aligned at any wet/dry ratio.
Status
Core DSP — envelope follower, FIR filter pair, waveshaper, bass phase quadrature, ring mod, input delay, and wet/dry mix — is tested. The UI is functional with live metering. The FIR coefficients are recomputed per-block on cutoff changes; rapid parameter automation may produce brief tonal artefacts at the crossover during the transition.