Acoustic Lib
by BMProjects
Acoustic Lib is a NeoForge library for 1.21.1 that lets a server start, stop and update custom OGG sounds for selected clients.
What it does
Acoustic gives other mods an API for server-driven audio playback. A server-side mod can target a sound at chosen players, stream OGG assets directly from the mod's files, and control loops with loop counts, infinite loops, and start or end offsets. Fades, runtime volume changes and runtime pitch changes can be applied while a sound plays.
Optional player predicates are checked on the server before any packet is sent, so only matching players receive a sound. Music arbitration handles exclusive tracks, fading out vanilla music when a custom track takes over. The library is meant for ambience, scripted music, boss themes and event sounds that the vanilla sounds.json system does not cover well. It adds no gameplay content of its own.
Installation needs Kotlin for Forge. Acoustic Lib runs on client and server, so the server and every player need it. It is published for NeoForge 1.21.1 only, with 0.2.0 as the latest file, and all rights are reserved under a license that is not open source.
Key features
Server-driven playback
A server-side mod starts, stops and updates custom OGG sounds for the players it selects.
Looping and offsets
Sounds can loop a set number of times or forever, and can begin or end at chosen offsets.
Fades and runtime changes
Volume and pitch can be changed while a sound plays, and playback can fade out.
Player predicates
Before any packet leaves the server, an optional player predicate decides which players are sent a given sound, so only matching clients receive it.
Music arbitration
Exclusive tracks can fade out vanilla music while they play, so two tracks do not compete.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Who it’s for: Mod developers building server logic that needs targeted audio, and server owners running mods that depend on it. Players without such mods have no use for it on their own.
How it compares
AudioLayer is open source under the MIT License and runs on NeoForge 1.21.1. Mr Codex's better record player is also open source under the MIT License, and it runs on client and server for 1.21.1. Dash's Custom Music Discs Mod is not open source, is under All rights reserved, and is published for client and server on 1.21.1. The alternatives add playback to records or items, while Acoustic Lib is a library for server-driven audio.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Acoustic Lib | NeoForge | 1.21.1 | Client and server | 2026-08-29 |
| AudioLayer | NeoForge | 1.21.1 | Not published | 2026-07-12 |
| Mr Codex's better record player | NeoForge | 1.21.1 | Client and server | 2026-07-07 |
| Dash's Custom Music Discs Mod | NeoForge | 1.21.1 | Client and server | 2026-06-05 |
Questions
Does Acoustic Lib need Kotlin for Forge?
Does every player need Acoustic Lib?
Which game versions are supported?
In the catalog
Acoustic Lib is one of 3,514 Library mods on ModsFinder, and one of 1,449 Library mods for NeoForge. 32,366 mods support Minecraft 1.21.1.
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What the author says
Acoustic lets a server-side mod start, stop, and update custom OGG sounds on selected clients. It is built for ambience, scripted music, boss themes, events, and other cases where vanilla sounds.json playback is too limited. Acoustic is a library-style mod. It does not add gameplay content by itself; it provides an…
Official listing
- Modrinth page
- modrinth.com/mod/acoustic-lib
- Owner
- BMProjects
- Published
- 2026-06-14
- Updated on Modrinth
- 2026-08-29
- Facts verified
- 2026-10-15