Headline: all audio is now encrypted (AES-256-GCM), keyed by a per-profile password. Mandatory — v3.3 only interoperates with v3.3+. Encryption - RemSoundCrypto (Core): PBKDF2 key derivation, AES-GCM encrypt/decrypt (low-alloc, into-span), password fingerprint, light on-disk obfuscation. - Wire: SenderLane encrypts the audio payload (PCM split across parts when the +28 overhead crosses MTU); AudioReceiver/StreamSession decrypt via a shared single-thread AudioDecryptor. Fingerprint piggybacks on the Format packet (offset 36, backward-compatible) so a peer can detect a password mismatch. - Profile.Password (scrambled), carried through BuildCurrentProfile; MainForm derives + pushes the key/fingerprint to sender + receiver (RecomputeAudioCrypto). - UX: ask-for-password on profile create; File -> Change this profile's password (ProfilePasswordDialog); Options -> Profile passwords (manager); a gate that prompts before streaming without a password; and a clear "passwords don't match" / "peer needs to update" message driven by the fingerprint. Cue fixes - CuePlayer (NAudio) replaces System.Media.SoundPlayer, which silently failed on the 96 kHz/24-bit cue WAVs (and any custom file) — cues now play reliably, resampled to 48 kHz/16-bit. Also fixes the Preferences preview button. - Connect/disconnect cues now audio-gated with hysteresis: connected when audio flows OR heartbeat healthy; lost only when audio stops AND heartbeat unreachable. Kills false disconnects and the receive-only "no cues" case. - Honest cue logging (played / muted / not loaded). Smaller - Endpoint stickiness: keep the audio target pinned to the heartbeat-proven address instead of chasing a multi-homed peer's other (unreachable) address. - "Online/offline" label now audio+heartbeat aware, not discovery-only. - "Show what's new after each update" preference (on by default). Docs: About v3.3 block, RELEASE_NOTES, README (encryption as a headline), manual section 12 "Passwords and encryption" (+ renumber), MANUAL.md regenerated. Version 3.2.0 -> 3.3.0. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
RemSound
Free Windows app for sending live audio between two computers — across a house, across a city, or anywhere your internet reaches. Encrypted end to end, low delay, great quality, fully accessible to screen-reader users.
Download the latest version · Read the user manual
RemSound is for musicians, sound designers, podcasters, and anyone else who wants to share audio between two Windows machines with as little delay as possible.
You sit at one computer, RemSound captures whatever is playing — a track in your music software, a video call, system sound from anything else running — and sends it cleanly to another computer where it plays through speakers or headphones in real time. The person at the other end hears what you're hearing, with a delay measured in milliseconds rather than seconds.
It's also fully accessible. The interface was designed with screen readers (NVDA in particular) in mind from day one. Every button has a keyboard shortcut, every status line is read out clearly, and there are no menus or controls that need a mouse to reach.
Private by default — your audio is encrypted
Everything RemSound sends is encrypted end to end: scrambled the moment it leaves your computer and only unscrambled at the other end, so nobody in between — your internet provider, a shared Wi-Fi, anyone watching the line — can listen in. You no longer need a VPN just to keep a private connection private.
It works with a simple shared password. You and the person you're connecting to use the same password, and only the two of you can hear the audio — get the password wrong and nothing comes through. RemSound stores a password on each profile and walks you through setting one. And it all adds no delay you'd ever notice.
What you can do with it
- Listen to one of your computers from another room. Sit at your laptop and hear what's playing on your desktop. Walk around the house — the sound follows you.
- Play music together over the internet. Two musicians at different houses can play along together with very low delay. Much faster than a video call, fast enough that timing-sensitive playing works.
- Send a finished mix to a producer or client in real time, without uploading a file and waiting.
- Record what comes through the connection to WAV, MP3, OGG-Opus, or FLAC. Save sessions for review later.
Three quality settings, simple choice
Inside RemSound there's just one main decision: which quality and delay you want.
- PCM 48K 24 bit — uncompressed. The best possible sound. Uses about 2.3 megabits a second. Use it when both computers are on the same local network.
- Opus, broadcast quality — loss tolerant. Compressed, very good sound, only 200 kilobits a second. Robust against patchy connections. Use it across the internet.
- Opus, live latency — for jamming and monitoring. Compressed, ultra-low-latency mode. About 5 milliseconds of delay added by the codec itself, very close to PCM. Best when you and the person on the other end are playing along together over a clean network.
How to install it
- Go to the latest release.
- Download the file called
RemSound-v3.3.zip(the version number changes over time — pick whichever is newest). - Extract the zip into a folder of your choice.
- Double-click
RemSound.exeand away you go.
The first time you launch, RemSound will offer to install Microsoft's .NET 10 Desktop Runtime if you don't already have it. Free, just say yes.
After that, RemSound updates itself. Help → Check for updates pulls the next version, or you can tick a box in Preferences and let it install updates quietly in the background.
What you'll need
- Windows 10 or 11. Some users run it successfully on Windows 7, but it's not officially supported there.
- Another person running RemSound on their own Windows machine.
- A way for the two machines to reach each other on the network. Both on the same Wi-Fi works. Both on the same Tailscale network works (free and easy to set up). Or both pointed at the public RemSound relay (also free, no setup).
Learn how to use it
The full user manual is right here on GitHub: Read the user manual. It covers getting connected for the first time, every setting and what it does, troubleshooting tips, and a glossary at the end. It's the same manual you can press F1 to read from inside RemSound, so you can read it before installing if you want to see what you're getting.
Questions or problems?
File an issue. Bugs and questions are welcome and someone will get back to you.
Who made this
RemSound was built by a sound designer who wanted to listen to one of his computers while sitting at another, and couldn't find anything else that fit the bill. It's free, open-source, and yours to use however you like.
Licence
MIT. See LICENSE.