A lush plate reverb with a 70s and 80s digital soul.
Halcyon Verb is an algorithmic reverb for long, chorused tails that sit behind vocals, keys and guitars without crowding them. It runs as an Audio Unit in Logic Pro, and as VST3 or CLAP in most other music software.
Free while in beta. Version 0.1.4, built 15 October 2026. By downloading you agree to the licence agreement.
Built around one big knob
Decay sets how long the tail rings, from a tight 0.2 seconds to a 30-second wash. The rings spread further as the tail gets longer, so you can read the space at a glance.
Beside it, a live picture of the tail shows the predelay gap, the decay, and how fast the high end fades. Input and output meters sit next to it.
Ducking keeps the vocal in front
Turn up Duck and the reverb steps back while you sing or play, then blooms in the gaps between phrases. Long, lush tails without washing out the words.
The Duck knob shows it working: a level drops inside the knob as the reverb is pushed down, and rises again as the tail swells back. At 0% it's off, and the sound is unchanged.
Every control in plain sight
Mix, Predelay and Duck sit next to Decay. The rest are grouped the way they are in the plugin.
Mix and timing
- Mix
- Balance between dry and reverb, kept even in loudness.
- Predelay
- A gap of up to 500 ms before the tail, to keep vocals clear.
- Decay
- Tail length, 0.2 to 30 seconds.
- Duck
- Pulls the reverb down while the dry sound plays, so it blooms in the gaps.
Space
- Size
- From a small plate to a large hall-like space.
- Width
- Mono tail at 0%, natural at 100%, extra wide at 200%.
Tone
- Damping
- How quickly the highs fade inside the tail. Lower is darker.
- Low cut, High cut
- Shape what goes into the reverb.
Motion
- Rate, Depth
- Slow chorus inside the tail. This is where the vintage shimmer comes from.
Installing the beta
The beta installers aren't signed by Apple or Microsoft yet, so your computer asks you to confirm once.
macOS 11 or later
- Open
HalcyonVerb-0.1.4-macOS.pkg. - If macOS says it can't check the file for malicious software, click Done. Then open System Settings, go to Privacy & Security, scroll down and click Open Anyway.
- Follow the installer. It adds the Audio Unit, VST3 and CLAP versions for all users.
- Restart Logic Pro. You'll find it under Audio FX, then Audio Units, then Halcyon Audio.
Windows 10 or 11, 64-bit
- If your browser says the file isn't commonly downloaded, choose Keep. In Edge it's under the … menu next to the download.
- Run
HalcyonVerb-0.1.4-Windows-Setup.exe. If Windows says it protected your PC, click More info, then Run anyway. - Pick VST3, CLAP or both, and finish the installer.
- Rescan plugins in your music software. The VST3 goes to
C:\Program Files\Common Files\VST3.
About this beta
- Formats: Audio Unit (macOS only), VST3 and CLAP. Stereo in, stereo out.
- The Windows version is brand new and hasn't had much testing yet. If it doesn't show up or misbehaves in your host, we'd like to hear about it.
- Projects you make with this beta should reopen in later versions, but keep backups while things settle.
- More reverb modes and a vintage colour switch are planned.
File checksums (SHA-256)
feb1bbe95d97857845847ebb607ca6ab0c7bef4efaff70c9ee0bb2fc8344dc1b HalcyonVerb-0.1.4-Windows-Setup.exe 839739f4e6be59aeaf4c3c7a1f1c19f5a44e3c7dc92532366840a738a792d102 HalcyonVerb-0.1.4-macOS.pkg