Minimal Audio Wave Shifter

Offering modulation options that are rather different from the norm, and available in all the common macOS/Windows plug‑in formats, Minimal Audio’s Wave Shifter employs frequency shifting, ring modulation and amp modulation. The last of those is described as being similar to ring modulation but also including the original source audio frequencies. These allow treating the input signal in both musical and inharmonic ways. The amount of shift in frequency shift mode is applied to the whole audio spectrum, while ring modulation produces only sum and difference frequencies.

The frequency shifting process shares common ground with FM synthesis, with controls relating to frequency modulation, ratio and soft sync controlled by a modulation section that can be free‑running or sync’ed to tempo. The modulation LFO can be set to sine, triangle, ramp or square shapes, while a Randomise control modifies the modulation and an Offset control adjusts the relative phase of the left and right outputs. The Shape control morphs between the LFO wave shapes, unless Snap is enabled, in which case they change abruptly as the Shape knob is turned.

The FM section offers a choice of Sine, Even, Dirty, Noise, Input, Output or External as modulation sources, and rotary controls for Ratio and Amount. The large knob in the centre sets the oscillator frequency for the mode (frequency shifting, ring modulator or amp) that’s set using the Style box in the top right‑hand corner of the window. In frequency shifting mode, there are clear positive or negative shifts and the frequency can be switched to Fast, Tuned, Slow or Sync modes. In Tuned mode the frequency can be set via MIDI notes. When soft sync is on, the oscillator reacts to the input signal polarity, which adds an interesting harmonic timbre. To my ears, this produces a smoother sound at low modulation frequencies but it can be more obvious at higher modulation rates. Spread introduces a difference in the relative frequencies of the internal oscillators, to create stereo shifting effects.

The smoothest modulation effects are created when the Frequency control is set to Slow, with a rate of only a few Hertz.

As you might expect, the smoothest modulation effects are created when the Frequency control is set to Slow, with a rate of only a few Hertz. Note that the Frequency control can introduce both positive and negative frequency shifts. High rates create screeching FM‑type sounds that can work well on rhythmic sounds when controlled via the LFO section. The difference between frequency shift and FM is subjectively very noticeable so it comes down to picking the mode that works best for the current material.

Feedback Amount adjusts the level of the shifted output signal that’s fed back into the input, and at high values self‑oscillation can occur in some instances. The feedback can also be sync’ed to the host tempo, and a variable band‑pass filter shapes the signal being fed back. There’s also the expected wet/dry balance control, input gain and the option to apply input gain only to the affected signal. The output gain control is accompanied by a limiter with soft clip or gentle limit/saturation options.

Verdict

Having experimented with the plug‑in, my own view is that the more subtle modulations available here can work well on bass and pad sounds, while the more assertive treatments, especially if using a sync’ed modulation waveform, are a good fit for adding impact to rhythm loops or for turning static synth/guitar sounds into rhythmic elements. As with any FM or frequency shifting device, there’s plenty of scope for producing inharmonic chaos, so experimentation is the key. There’s a lot to like about Wave Shifter, especially if your music has an experimental edge.