Bombo

Half kick instrument, half 1992 BBS. One plugin.

Bombo is a free, open-source kick-drum synthesizer and rumble-FX plugin for techno, house, drum & bass, trap, and ambient. A two-voice kick engine (sub + synth/sample body) feeds a reorderable drive → filter → delay → reverb chain with reverse-bass sidechain ducking, six one-knob macros, a live scope, and a preset bank — all wrapped in a bomb-shaped chassis that hides a working 1992-style BBS terminal, complete with a playable mini-game.

🔊 Hear it - Field Test (25 s, made entirely in Bombo)

Formats: VST3, AU, CLAP, Standalone Platforms: Linux (x86_64), macOS (Apple Silicon + Intel), Windows (x64) License: GPL-3.0-or-later

Quick start

Download the latest build for your platform from the Releases page, extract, and run the installer:

./tools/install-linux.sh        # Linux
./tools/install-macos.sh        # macOS (ad-hoc signed; no Apple Developer ID)
tools\install-windows.ps1       # Windows (PowerShell)

Rescan plugins in your DAW. Bombo appears as Hyperfocus DSP / Bombo.

Features

Signal chain

Voice A (sub)  +  Voice B (synth or sample, mid/punch)
  → per-voice drive
  → DUCK (reverse-bass: Off / A / B / AB)
  → FX bus: Drive → Filter → Delay → Reverb   (reorderable per preset)
  → limiter → OUT

Sound engine

• Two-voice kick — Voice A is the sub/body: a sine core with a tunable pitch envelope (start, end, decay, curve) and a sub high-pass. Voice B is the mid/punch layer and can be a synth voice or a loaded sample. A balance control crossfades the two.
• Transient + noise — adjustable click (amount + center frequency) and a noise layer with a color control, for snap and air on top of the body.
• Drive — per-voice saturation (amount / mode / bias) plus a separate FX-bus drive stage with its own mode and mix.

Effects chain (reorderable)

• Filter — high-pass and low-pass with resonance, plus color and teeth voicing.
• Delay — tempo-synced with sub-sample-accurate timing, feedback, morph, smear, and mix.
• Reverb — multiple algorithms with size, decay, damping, diffusion, pre-delay, and mix.
• Drag to reorder the Drive → Filter → Delay → Reverb stages; the order is saved per preset.

Ducking

• DUCK routing — reverse-bass sidechain ducking that cycles Off → A → B → AB, so you can duck the sub, the body, or both for classic reverse-bass movement. A separate always-on wet-bus tail duck keeps reverb/delay tails out of the way of each hit.

Workflow

• Macros — six one-knob shapers on the bomb's nose (PITCH, DECAY, PUNCH, WEIGHT, MOOD, SPACE) plus the OUT hero knob.
• Scope — a live output-waveform strip across the top of the UI.
• Preset bank — 10 curated factory presets plus full user preset save / rename / delete.
• Six themes — VAULT (default), BANDW, CYBER, MATRIX, NIGHTRUN, PLASMA.
• Offline bounce — render the current kick straight to WAV or AIFF; runs offline against a fresh DSP instance, so live audio keeps flowing and the result is reproducible.
• Optional key-tracking so the kick follows incoming MIDI note pitch.

HYPERFOCUS BBS

Tap into the bomb's nose to dial up a 1992-style bulletin-board terminal baked into the plugin — a BoomFeed and a playable Space-Impact-style mini-game (try the Konami code). It's a flourish, not a dependency: it touches none of the audio path.

Controls

Input	Action
T key	Fire a test kick
MIDI NoteOn	Trigger the engine (with optional key-tracking)
Click + vertical drag	Adjust any knob
Shift + drag	Fine control
Ctrl + click / double-click (knob)	Reset to default
Tap the nose (7×)	Open / close the HYPERFOCUS BBS
Esc	Dismiss the BBS from anywhere

Preset locations

User presets are stored under the per-user config directory:

Platform	Location
Linux	~/.config/Bombo/Presets
macOS	~/Library/Bombo/Presets
Windows	%APPDATA%\Bombo\Presets

Building from source

Requires CMake ≥ 3.22 and a C++17 compiler. JUCE 8 and the CLAP extensions are fetched automatically via CMake FetchContent.

Linux system dependencies (Debian / Ubuntu / Pop!_OS)

sudo apt update
sudo apt install build-essential cmake ninja-build \
    libasound2-dev libjack-jackd2-dev \
    libfreetype6-dev libfontconfig1-dev \
    libx11-dev libxcomposite-dev libxcursor-dev libxext-dev \
    libxinerama-dev libxrandr-dev libxrender-dev \
    libwebkit2gtk-4.1-dev libglu1-mesa-dev libcurl4-openssl-dev mesa-common-dev

Linux system dependencies (Arch / Manjaro)

sudo pacman -S --needed base-devel cmake ninja \
    alsa-lib jack2 freetype2 fontconfig \
    libx11 libxcomposite libxcursor libxext libxinerama libxrandr libxrender \
    webkit2gtk-4.1 glu mesa curl

git clone https://github.com/hyperfocusdsp/bombo.git
cd bombo

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j

# Run the standalone
./build/Bombo_artefacts/Release/Standalone/Bombo

LTO is on by default for release builds; pass -DBOMBO_LTO=OFF on memory-limited machines or for faster CI builds.

Tests

cmake --build build --target Bombo_Tests
ctest --test-dir build --output-on-failure

See TESTING.md for the manual sanity-check checklist.

Support and feedback

• Email: feedback@hyperfocusdsp.com
• GitHub Issues: open an issue

Your DAW + OS line and specific repro steps help most.

License

GPL-3.0-or-later. See LICENSE for the full text.