A new free synth · Halloween 2026

Synth'O'Ween, sounds from the other side

Screams in the night, doors that creak open by themselves, a choir that should have stayed buried. Twenty-five cursed sounds waiting under your keys. Play them. Bend them. Drown them in effects that should not exist.

Hear them scream ☕ Buy me a coffee

VST3AUmacOS Apple Silicon + IntelWindows 10/11Linux$0 · pay what you wantNo DRM

Watch it come alive

Ninety seconds inside Synth'O'Ween: 23 presets, from the Funeral Organ to the Braaam. Turn your sound up.

Open the cursed box

The plug-in, exactly as it will look in your DAW. Click MATRIX inside it to find what hides behind.

The Phantom Choir preset, with the playheads crawling over the waveform.

Who's buried here?

Ten factory presets, straight out of Synth'O'Ween. Click a grave to wake it up.

What lurks inside

Every sound in Synth'O'Ween is conjured by the plug-in itself: formant voices for the screams, string clusters, additive bells, friction for the creaking door. No sample library to install, nothing to license, nothing to clear for your videos.

Sample: 25 spooky sounds. START, END, CROSSFADE and TUNE shape the one you pick. CROSSFADE at 0 plays it once, turn it up and it loops forever.
Filter: low pass 12 and 24 dB, high pass, band pass, notch, plus two weird ones. Demon Vowel makes the sound speak, Haunted Comb turns it into a metal pipe.
LFO: 7 shapes, including Heartbeat and Chaos.
Modulation: 2 slots on the main page and 4 more in MATRIX, with a second envelope, glide and pitch bend range.
Trick or Synth: click the ghoul at the bottom right and a random nightmare is born.

Body count

7: Screamsghost howl, banshee wail, female scream, demon roar, witch cackle, wolf, whispers
5: Jump Scaresstinger, psycho strings, braaam, reverse riser, slam
5: Dronesabyss, cursed choir, dark organ, graveyard wind, hell rumble
5: Haunted FXcreaky door, heartbeat, thunder, rattling chains, blood drip
3: Bells & Boxeschurch bell, music box, theremin

25lost souls

29presets

7filters

10curses

The book of curses

Two effect slots, each with its own mix. The echoes follow your project tempo.

FX A

space & decay

Reverb: A clean room, small or large.
Haunted Hall: A vast hall haunted by a ghost an octave below.
Possession: Demonic pitch-down, growl and dirt.
Bone Crusher: Bit crushing and sample rate reduction.
Grave Tape: Wow, flutter, saturation and hiss from a tape left in the coffin.

FX B

time & torment

Delay: A tempo-synced, cross-fed stereo echo.
Banshee Echo: Every repeat climbs a fifth higher.
Reverse Spectre: The sound comes back from the past, backwards.
Heartbeat Gate: The sound pulses lub-dub, on the beat.
Ring of Hell: A wobbling ring modulator for metallic voices.

Take it home

Free for macOS (VST3 + AU, Apple Silicon + Intel), Windows 10/11 (VST3 64-bit) and Linux (VST3 + LV2). It crawls out of its grave just in time for Halloween.

Enter your email and the macOS and Windows downloads open right away. No license to activate.

Get it free · Mac & Windows ☕ Buy me a coffee

The summoning ritual

macOS

Unzip the download.
Copy SynthOWeen.vst3 to ~/Library/Audio/Plug-Ins/VST3 and SynthOWeen.component (AU) to ~/Library/Audio/Plug-Ins/Components.
Or double-click fix_mac_plugins.command: it installs, unblocks and rescans the plug-in for you.
Restart your DAW and rescan plug-ins. In Ableton Live: Settings → Plug-Ins → Rescan.

Windows

Unzip the download.
Copy the SynthOWeen.vst3 folder to C:\Program Files\Common Files\VST3.
Restart your DAW and rescan plug-ins. In Ableton Live: Options → Preferences → Plug-Ins → Rescan.

Linux

Unzip the download.
Copy SynthOWeen.vst3 to ~/.vst3 and SynthOWeen.lv2 to ~/.lv2.
Restart your DAW and rescan. Works in Bitwig, Reaper, Renoise and Ardour (x86_64, Ubuntu 22.04 or newer).

If macOS blocks it

The plug-in is not notarized by Apple yet, so macOS may lock it away. Paste this into Terminal, then restart your DAW:

xattr -dr com.apple.quarantine ~/Library/Audio/Plug-Ins/VST3/SynthOWeen.vst3 ~/Library/Audio/Plug-Ins/Components/SynthOWeen.component

Leave your mark

Which sound scared you most? What did you make with it? What should haunt the next version? Sign in with a free GitHub account to post.

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Feed the ghost

Synth'O'Ween is free and stays free: no subscription, no account, no crippled demo. If it haunts one of your tracks or Halloween videos, a coffee pays for the dev hours and the next plug-ins.

☕ Buy me a coffee