Thwack

Overview

Thwack is a drum machine and drum synthesizer for Android tablets and phones. It follows the workflow of the classic x0x boxes: a 16-step sequencer, a pad per voice and one knob per parameter, built to be played live.

Every sound is synthesized in real time. There are no samples: each voice is a small synth you can reshape while the pattern runs.

Twelve synthesized voices

Kick, snare, clap, rim shot, three toms, closed and open hats, crash, ride and shaker, modeled after the character of classic analog drum circuits: analog-style envelopes, pitch sweeps, a six-oscillator metallic cluster for the hats and cymbals, a multi-pulse clap. Each voice has its own sound-design controls (kick sweep, attack and drive, clap spread, hat harmonic and sizzle, ride ping), and the shaker doubles as cabasa, castanets and guiro.

The MIX page adds per-voice pan, a compressor with a kick sidechain, and a room, hall or plate reverb. Five LFOs (sine, triangle, saw, ramp, square, sample and hold), free-running or synced to the tempo, can bend any knob around its set position.

A sequencer built for live sets

• 16 steps, each split into 4 substeps for ratchets and rolls, with triplet steps mixed freely per lane
• Trig conditions per step: fill, first playthrough, probability, and X of every Y
• Pattern lengths from 1 to 16 steps for odd meters and polyrhythms
• Up to 8 pattern chains, with live cues that jump on the boundary you choose
• Copy, move and clear are staged and confirmed with a second press, so an edit lands exactly when you want it
• A 32-step undo history, and step record from the pads or a MIDI controller

Performance ribbons

Two ribbons sit on the grid's edges. FILTER sweeps a low-pass one way and a high-pass the other, with a per-voice bypass so the kick can stay dry while the hats get swept. FILL plays like a drummer taking a fill: ghost notes and tom pickups low on the ribbon, growing into full snare rolls at the top, always landing back in the bar.

Free and Pro

The free edition is the whole instrument: the synth, the sequencer, step record, presets and preset files, and playing the drums from a MIDI controller.

The Pro Edition, a one-time in-app purchase, adds:

• Full MIDI integration: clock in and out, note out, MIDI assign for every knob, and MIDI map files
• In-app recording: 24-bit WAV takes, with a stem per drum
• Direct outputs: route each drum to its own output on a multichannel USB interface

Coming to Google Play

Thwack is planned for early 2027 on Android 10 and later. It has no accounts and needs no network: kits, patterns and sequences are saved on the device.