In the fall of 2023, Baby Audio acquired Denise Audio, a company with an awesome line of deceptively-simplified plug-ins.Motion Filteris their reworking of Denise's The Sweeper, a digital motion filter that includes two dynamic motion modes with lots of control over a variety of possible sounds. I've generally had a hard time with filter plug-ins, finding that they sometimes offered up far too many controls or simply just didn't give results right out of the gate. Filter concept is simple; either a low or high-pass filter or a specific frequency interval is selected – basically an EQ. A motion filter then adds control over the frequency points, and uses a detector to change those points' values based on input. This input can be the volume of the audio source itself (an envelope follower, like the Sweeper here), an outside (sidechain) source (click the chain in the upper right GUI), or a low frequency oscillator (LFO here). Controls forMotion Filterare fairly straightforward and easy to use, and with a wide parameter range and filter slopes ranging from 12 to 96 dB/octave, one can get into some pretty extreme results. I loved how the presets gave me a tour ofMotion Filter'spossibilities, and several featured static filters – without motion – performing EQ-based tasks with impressive results. Other presets had all kinds of interesting pulsing sounds and wobbly effects; sounds that livened up some static keyboard patches and percussion that was boring me beforehand. I love theMotion Filterplug-in, it's low cost (look for sales!), and it gets right to work.

($69 direct;deniseaudio.com) -LC