HD Instruments has released Spectdrum, a rhythmic spectral gate plugin for macOS and Windows.
The tagline is “Make it Pulse.” Spectdrum listens to an incoming sound, splits it into four frequency bands, and turns those bands into a moving groove built entirely from the original material.
Spectdrum is not a drum machine, and it does not add drum samples or synth voices. Every hit comes from the audio you feed into it, so a pad, drone, vocal, string patch, or field recording keeps its own texture while gaining rhythm, pulse, and movement.
It splits the signal into four bands named Sub, Low-Mid, High-Mid, and Air. Each band has its own frequency range, filter, pitch, stereo width, and drive, so you can shape the low pulse, midrange movement, and top-end shimmer separately.
There is a Learn function that places the four bands automatically, based on the spectral content of the incoming audio. It means you do not have to set the crossover points by hand for every new source.
Each band also has its own step sequencer with 1 to 32 steps, independent pattern length, per-step velocity, accents, and swing. And this is the part that makes Spectdrum different from a normal trance gate. Instead of chopping the whole signal with one pattern, it lets different frequency bands run their own rhythms.
That means a 7-step Sub pattern can roll against a 16-step Air pattern, making the groove evolve over multiple bars before it fully repeats. Patterns also respond to MIDI, so you can trigger them more like an instrument than a static insert effect.
Spectdrum includes hand-drawn envelopes for volume, filter, pan, and pitch on each band. You can draw curves to make a hit swell, sweep a filter through the bar, or bend the pitch on certain steps.
The plugin also includes per-band reverb and delay sends, plus a master section with filters, distortion, EQ, and a maximizer, so you can take the processed rhythm closer to a finished sound without leaving the plugin.
The pitch shifting sits inside the reverb and delay feedback loops, not just before them, so repeats can climb or fall as they decay.
Spectdrum was developed by Hagai Davidoff of HD Instruments, a composer and sound designer with three decades of work in music production, theater, and education. Thousands of producers use his Kontakt instrument expansions, and Spectdrum is his first standalone plugin.
Spectdrum is available for $69 as an introductory offer, with the regular price set at $99. The license uses an email plus code system with one online check, then works fully offline on up to three of the owner’s own computers. Free updates are included through version 1.
Spectdrum is available as a 64-bit VST3 plugin for Windows 10/11 and macOS 10.15 or newer, with AU support on macOS. The macOS version is a Universal Binary for Apple Silicon and Intel Macs.
More info: Spectdrum ($69 intro price)
Last Updated on August 13, 2026 by Tomislav Zlatic.
