RemSound — user manual

RemSound is a Windows program that sends live sound from one computer to another, with very little delay. Picture a private audio link between two or more computers: each one decides what sound it wants to send and what sound it wants to play, and the audio travels straight between them over your network.

It was built for playing music together over the internet — a guitarist on one computer and a singer on another, hearing each other in real time — but it works just as well for listening to one room from another room in your house, co-hosting a podcast, or anything else where you want to get sound from one PC to another, fast.

Table of contents

1. What RemSound does
2. Quick start
3. Profiles
4. The main window: menu bar + three tabs
5. Menus (File, Record, Options, Help)
6. Connectivity tab
7. Audio inputs and outputs tab
8. Audio profile tab
9. ASIO and WASAPI
10. Peers — finding and connecting
11. How the network works (LAN, WAN, Tailscale)
12. Latency and audio quality
13. Keyboard shortcuts
14. Global hotkeys (mute, volume, tray, recording)
15. Remote control: adjusting a peer's listening volume from your end
16. Startup behaviour
17. Updating RemSound
18. Recording to a file
19. Logs and diagnostics
20. Troubleshooting
21. Glossary

1. What RemSound does

RemSound carries sound from one PC's microphone or sound card to another PC's speakers or audio interface, almost instantly, over your network. Both computers run the same program, and each one decides for itself whether it wants to send sound, receive sound, or do both.

The basic flow

There is no central server, no account, and nothing stored online. The sound goes straight from one computer to the other.

2. Quick start

Let's assume you and a friend both have RemSound running, and that your two computers can reach each other on the network (the same Wi-Fi, the same Tailscale account, and so on).

1. Start RemSound. The first thing you'll see is the profile picker. On a brand-new install your only choice is (Blank template) — select it and press Enter or click OK. Later, once you've saved a setup or two of your own, this is the dialog where you choose which one to load. See Profiles for the full story.
2. Once the main window opens, go to the Audio inputs and outputs tab. Tick Receive audio (Alt+R), then tick the device you want incoming sound played through in WASAPI outputs for received sound (Alt+3).
3. On the same tab, tick Send my audio (Alt+S) and tick your microphone in WASAPI inputs to send (Alt+5).
4. Go to the Connectivity tab, find your friend in the Discovered peers (Alt+D) list, and tick them. If they aren't showing up, use Add peer by IP (Alt+A) and type their address.
5. Have your friend do the same with you on their computer.
6. Within a second or two, both of you will hear each other.
7. In the File menu (Alt+F), choose Save as to give your setup a name. Next time you start the program, picking that name from the startup dialog restores all your settings, device choices, peers, and connections in one go.

3. Profiles

RemSound saves your whole setup — which devices are ticked, whether you're sending or receiving, your sound quality settings, delay targets, hotkeys, your ASIO driver choice, remembered peers, currently connected peers — into a single settings file. Each saved setup is called a profile. You choose which profile to load every time you start the program. You might keep one profile for “morning podcast” and another for “evening jam session”, each with a different mix of devices ticked, and switch between them in a couple of clicks.

The startup picker

When RemSound starts, the first thing you see is the profile picker. It is a list of your saved profile names, with an extra entry called (Blank template) at the top. The keys are deliberately simple:

The first profile in the list is highlighted to begin with, so on a fresh install where the only entry is (Blank template), you just press Enter to get going.

What “Blank template” means

The blank template is a one-off session with all the defaults: nothing ticked in any device list, neither Receive nor Send turned on, the standard sound settings, no ASIO driver chosen, no remembered peers, and the standard hotkeys. You'd pick it for a quick session you don't plan to save, or as a clean starting point for a new profile. The Save button is hidden while you're on the blank template — there's no existing setup to update, only a new one to save.

Saving and updating

The File menu has two ways to save:

The window title bar always shows which profile is in use: RemSound — Active profile: My session name.

Switching, renaming, and deleting

Where profiles are stored

Each profile is one small file on your computer. By default they live at:

<RemSound folder>\profiles\<your computer name>\<profile name>

The folder named after your computer keeps each machine's profiles separate. If you used the Browse… button on the startup dialog to pick a different folder (for example, one inside Dropbox), the profiles are stored directly in that folder — with no per-computer subfolder — so two computers pointed at the same shared folder see exactly the same list.

You can also copy a profile file from one computer to another: drop it into the other computer's profile folder and it will appear in that computer's startup dialog. If the other computer doesn't have the same equipment (different sound cards, different ASIO drivers), those device choices are simply skipped when the profile loads — RemSound won't show an error or a warning, the relevant lists just won't have those items ticked.

What is NOT saved in a profile

A few things are deliberately kept out of profiles:

• The folder profiles are read from. You choose this with the Browse… button on the startup dialog. It's kept in a small settings file on that particular computer.
• Live connection health figures — these describe what's happening right now, not your setup.
• Anything auto-tune has learned — this is worked out fresh each session.
• Window position and size — Windows itself remembers these.

4. The main window: menu bar + three tabs

The main window has three parts, stacked top to bottom:

1. A menu bar at the top with four menus — File, Record, Options and Help. See Menus.
2. A row of tabs with three tabs — Connectivity, Audio inputs and outputs, Audio profile. Each tab has its own Alt+letter shortcuts that only work when that tab is the one showing — so the same letter can do different things on different tabs without clashing.
3. A status line at the bottom that updates once a second with how long you've been connected, how many peers you have, whether sound is flowing, and connection health.

5. Menus (File, Record, Options, Help)

There are four menus on the main window: File (Alt+F), Record (Alt+K), Options (Alt+O) and Help (Alt+H). The Record menu opens with Alt+K rather than Alt+R because Alt+R is already used by the Receive audio checkbox on the main window. The menu's title is shown as “Record (Alt+K)” so you can find the shortcut even though there is no K in the word.

File menu

The File menu holds everything to do with profiles — opening, saving, renaming — plus minimising to the tray and exiting.

Record menu

The recording feature can save what you're sending, what you're receiving, or both, to a file on your computer as a WAV, MP3, OGG-Opus or FLAC file. See Recording to a file for the full chapter; this is just the menu summary.

Options menu

The Options menu gathers everything you might want to configure about the app — recording settings, keyboard shortcuts, startup behaviour, and general preferences.

Help menu

The Help menu opens this manual, checks for updates, and shows the About dialog.

6. Connectivity tab

This is where you manage peers and reach the logging options. The controls on this tab, in tab order:

7. Audio inputs and outputs tab

This tab controls everything to do with which sound devices are involved. The ASIO driver picker at the top decides whether ASIO is being used at all. The Receive side and the Send side each have their own master checkbox and their own device lists.

All the device lists are checkable lists — tick or untick an item to include or exclude that device. Profiles save which devices are ticked; the blank template starts with everything unticked.

Receiving

To receive sound you need two things: Receive audio ticked, and at least one output device ticked. Without an output device, even when sound arrives there is nowhere for it to go.

Tick as many outputs as you like across the WASAPI and ASIO output lists — the same received sound plays out of all of them. Common combinations:

• One output: just your monitors or headphones.
• Studio monitors through ASIO plus a wireless headset through WASAPI, so you can move around the house.
• Two physical outputs, one for each of two rooms.

Hearing everyone with one output ticked. A peer always tells you which sound path it's sending from. On your end, if you only have one type of output device ticked, sound from a peer using the other type is still routed through whatever output you do have ticked. So a single ticked output is enough to hear everyone.

Sending

To send sound you need Send my audio ticked, plus at least one capture source ticked across the three send lists.

Tick any combination across the three lists. RemSound mixes them together into one stream and sends that to all your chosen peers. So you can send a mic plus a guitar plus your system sound all at once, mixed together, and your friends hear all three.

8. Audio profile tab

Everything that shapes the trade-off between sound quality and delay lives here. The first control on the tab is the priority mode checkbox — it sits on its own at the top because it has the biggest single effect on how the audio feels in the first few seconds. Below it are two groups: Audio send parameters first, then Audio receive parameters.

Use CPU and Windows performance settings in high priority mode (Alt+U)

This is the first control on the tab. When it's ticked, RemSound asks Windows to keep it running at full speed the whole time RemSound is open under this profile.

The effect is that the “the first few seconds sound rough, then it warms up” behaviour goes away — nothing in the system is allowed to coast while RemSound is sitting quietly between bursts of sound.

This is a per-profile setting, so you can have one profile for live sessions where it's on, and another for casual background listening where it stays off. Turning it on or off marks the profile as having unsaved changes; save the profile to keep your choice.

The cost on a desktop is a couple of extra watts while RemSound is open. The cost on a laptop running on battery is that the battery drains a bit faster over the session, because the processor stays more wakeful instead of dozing — RemSound's own workload doesn't change, the processor just doesn't sleep as deeply. The setting is reversed automatically when RemSound closes (or when you untick it), so it's fine to leave the app running with the box ticked for a whole session, and turning it off partway through works too.

None of the other apps on your computer are affected. RemSound only asks Windows to keep itself running at full speed; Windows still saves power on everything else as normal, so your screen reader, browser and background programs are untouched.

Audio send parameters

Audio receive parameters

What you see in this section depends on whether an ASIO driver is chosen on the Audio inputs and outputs tab. With no ASIO driver, you see one delay setting (labelled simply “Audio latency”). With an ASIO driver chosen, you see two delay settings — one for each sound path — each with its own auto-tune toggle. The two paths are independent: a problem on one doesn't affect the other.

Most people only need to pick a codec and a smoothness level, and leave everything else at its default.

9. ASIO and WASAPI

RemSound can use two different ways of handling sound. Which one it uses depends on the ASIO driver (Alt+D) list at the top of the Audio inputs and outputs tab.

WASAPI (the default)

WASAPI is the normal Windows way of handling sound — every speaker and microphone in your Windows sound settings works this way. The delay added by capturing or playing through WASAPI is usually 10–30 milliseconds. Everyone running RemSound has WASAPI; no special equipment is needed.

ASIO (needs a driver)

ASIO is a faster, more direct way of handling sound used by professional audio equipment. ASIO drivers talk straight to the hardware, giving a hardware delay of under 5 milliseconds. It only works if your audio interface came with an ASIO driver.

The ASIO driver picker doesn't appear at all on a computer with no ASIO drivers installed. Common drivers that do appear:

• Audient USB Audio ASIO Driver — for EVO 4 / 8 / 16 and iD-series interfaces.
• Komplete Audio ASIO Driver — for Native Instruments interfaces.
• Focusrite USB ASIO — for Scarlett, Clarett and Red.
• RME ASIO — for Babyface, Fireface and UCX.
• Realtek ASIO — bundled with some Realtek drivers. Best avoided — it's a generic driver that can grab whatever Windows considers the default device, which often clashes with your screen reader's sound.

How the driver picker decides

One control, two outcomes:

On a fresh install the choice is (none). If you have an ASIO driver and want to use it, select it in the picker. To go back to WASAPI only, select (none).

ASIO channel pairs

ASIO doesn't list “devices” the way Windows does. Instead it gives you a list of channels (usually 2, 4, 6, 8 or more, depending on the interface), grouped into stereo pairs. RemSound labels each pair with the driver name, the pair number, and the channel names the driver itself reports. For an Audient EVO 8 you'd see entries like:

Audient USB Audio ASIO Driver — Pair 1 (channels 1/2): Mic | Line | Instrument 1 / Mic | Line 2
Audient USB Audio ASIO Driver — Pair 2 (channels 3/4): Mic | Line 3 / Mic | Line 4
Audient USB Audio ASIO Driver — Pair 3 (channels 5/6): Loop-back 1 (L) / Loop-back 2 (R)

Buffer size for ASIO

RemSound has no buffer-size control of its own. To change the ASIO buffer size, open the control panel program that came with your audio interface (such as NI's Komplete Audio Control Panel or the Audient EVO software) and set it there. The driver remembers its buffer size between sessions; RemSound simply uses whatever the driver is set to.

Same driver, sending and receiving, on one computer

RemSound supports this — you can capture from your audio interface and play received sound out of the same interface at the same time, on the same computer. Most modern professional audio drivers handle this fine.

10. Peers — finding and connecting

A “peer” is another computer running RemSound that you want to talk to. You manage peers on the Connectivity tab. It has three lists, all of them checkable:

There's also the Add peer by IP (Alt+A) button, which opens a small box for a computer name or address. It's useful for a first connection over a VPN, where discovery hasn't reached the other computer yet.

You only hear peers you've ticked

Even if a peer is sending sound your way, you won't hear it until you've ticked their checkbox. This is deliberate — connecting is a step where you give your consent. A peer's name appears in Discovered the moment they come online, but they can't make any sound on your speakers until you say yes.

Connection health

For each connected peer, the status read-out at the bottom of the window shows a small health note: the latest round-trip time in milliseconds, or pending, stale or unreachable if the regular check-in messages have stopped. (Round-trip time is how long sound takes to travel to the other computer and back.) RemSound plays a connect cue (a short sound) when a peer becomes healthy and a disconnect cue when one becomes unreachable. You can silence both cues using Cue sounds in the Preferences dialog (Options → Preferences, or Ctrl+P).

11. How the network works (LAN, WAN, Tailscale)

RemSound communicates on two network channels:

One audio channel number is used for everything — Tailscale, local network connections, and any relay server. You never need to type a channel number after an address; the default is assumed. Both sides of a connection do need to use the same audio channel number.

The health check-ins travel on the same channel as the audio, so if your sound reaches the other computer, your check-ins do too — one firewall rule covers both.

Network priority

RemSound automatically asks Windows to treat its audio as high-priority traffic, which helps most on a busy Wi-Fi network where other devices are streaming, downloading or video-calling. There's nothing to set up — it happens on its own every time RemSound starts. This helps on your local network and your home Wi-Fi; it makes no difference once the traffic leaves your home, but it does no harm either.

LAN — same Wi-Fi or Ethernet

On a normal home network, finding peers and checking their health both work with no setup. Start RemSound on two computers and they'll see each other within a second or two. You usually don't need to change any firewall settings.

WAN — computers in different places

Connecting two computers directly across the internet needs one of these:

• A VPN that puts both computers on the same private network — Tailscale is the one we recommend. (A VPN is a service that creates a private network linking your computers wherever they are.) Each computer gets a Tailscale address (it looks like 100.something) and they can reach each other directly.
• Or, port forwarding on each end's router (this is more involved and isn't covered here).

Finding peers on Tailscale and other VPNs

The ordinary “I'm here” announcements that work on a home network don't travel across a VPN. RemSound works around this by also sending announcements directly to every address in your Remembered peers list. So:

1. One time only: each side adds the other's Tailscale address to its Remembered peers list (using the “Add peer by IP” button).
2. From then on, RemSound sends announcements straight to those addresses every 1.5 seconds.
3. The other side hears the announcement, adds the sender to its own list, and announces back.
4. Within seconds, both sides see each other in Discovered peers, with no further typing.

So the rule is: only one side has to type the other's address once. After that, the discovery works both ways on its own.

Round-trip time and what it means

Round-trip time is how long it takes for sound to travel to the other computer and back.

12. Latency and audio quality

Latency is the small delay between sound leaving one computer and arriving at the other. Five controls together shape the trade-off between latency and sound quality, all on the Audio profile tab:

• Audio latency in milliseconds (Alt+L) — the main target for how much sound the receiving side keeps in reserve.
• Buffer smoothness (Alt+B) — how hard the receiving side works to protect against sudden jitter.
• Packet size (Alt+P) — Standard or Small. Small packets shave a couple of milliseconds off the sending delay, but double how many packets are sent.
• Lock to audio clock (Alt+D) — ties the timing of packets to the sound device's hardware clock, removing wobble caused by Windows.
• Continuous auto-tune — lets the receiving side choose the latency target for you, re-checking every few seconds.

Plus the codec choice (PCM, Opus 20 ms or Opus 10 ms), also on the Audio profile tab. Most people only need to pick a codec and a smoothness level and leave the rest at the default.

Audio latency control

The Audio latency control tells the receiving side how much sound to keep in reserve as a cushion against uneven network timing. A bigger cushion means more delay but fewer clicks. A smaller cushion means less delay but more clicks when the network wobbles.

Smaller is better when the network can handle it. If you'd rather not think about this number, turn on continuous auto-tune (below) and leave it.

Buffer smoothness

The Buffer smoothness list is a 1-to-10 scale for how patient the receiving side is when network jitter spikes. The default is 3.

Smoothness and the Audio latency control work together — smoothness controls how the receiving side reacts when sound runs late; the latency value controls how big a head-start it builds up. A practical tip: if you can hear clicks, try raising smoothness by one or two before you reach for a bigger latency value.

Packet size — Standard or Small

Two choices: Standard (the default) and Small. This controls how much sound each network packet carries:

The saving is small — at most a few milliseconds end to end. Small packets are useful when you and your collaborator are on the same local network and want to chase every last millisecond. For any internet connection it's a false economy, because doubling how many packets are sent also doubles the chance of running into jitter at the wrong moment, which you hear as clicks.

Lock to audio clock

The Lock to audio clock checkbox ties RemSound's sending timing to the sound device's own hardware clock, instead of letting Windows decide the pace. It's off by default. The label tells you what it does in your particular setup:

Continuous auto-tune

The Continuous auto-tune latency checkbox hands the latency value over to RemSound itself. When it's on, RemSound watches how evenly packets are arriving, every few seconds, and nudges the latency target up if it's seeing late packets, or down if the network has been calm. The companion Auto-tune latency interval (Alt+I) combo box sets how often it re-checks — 3, 5, 10, 15, or 30 seconds. Faster values react quickly to a change in the network but can feel a bit twitchy. Think of continuous auto-tune as a hands-off way to keep the cushion the right size as your network changes through the session.

If you turn auto-tune off, the latency value just stays wherever it last was.

Artefact sound type

When the playback reserve briefly runs empty, RemSound has to fill the gap with something. The Artefact sound type list decides what that gap sounds like:

• Noise burst (default) — a brief soft hiss that blends into music. Easy on the ear; it tells you something happened without being jarring.
• Click — the gap is left unfilled, so you hear an obvious click each time. Use this when you want to hear every problem (for example, while you're tuning the latency down).

Opus repairs lost sound automatically (built in, no setting)

Both Opus modes can automatically repair lost audio: each packet quietly carries a small backup copy of the previous packet's sound, so the receiving side can rebuild any single packet that goes missing on the way. The result is that a single missing packet becomes inaudible — no click, no glitch — instead of the small pop you'd otherwise hear. Two missing packets in a row still produce one click; that's just a limit of how Opus works, not something you can change.

This happens on its own — there's no switch for it. PCM mode doesn't have it.

Codec choice

Remember, the codec is the method RemSound uses to package the sound before sending it.

PCM gives the very best sound with no quality loss at all, but it uses about 30 times the network bandwidth of Opus. Over the open internet, Opus is almost always the right choice.

13. Keyboard shortcuts (within the main window)

Each tab has its own Alt+letter shortcuts. The same letter can do different things on different tabs without clashing — the shortcuts only work on the tab that's showing. Move between tabs with Ctrl+Tab and Ctrl+Shift+Tab.

Connectivity tab

(The logging controls — Enable logs and Write logs now — are in the Preferences dialog; reach it via Options → Preferences or Ctrl+P, then use Alt+L / Alt+W within the dialog.)

Audio inputs and outputs tab

Audio profile tab

Some of these shortcuts shift depending on whether an ASIO driver is chosen. When one is chosen, the ASIO-path controls take the simpler Alt+L / Alt+T shortcuts, and the WASAPI-path controls move to Alt+W / Alt+Y so they don't collide.

File menu shortcuts (work from any tab)

Always available

14. Global hotkeys (work even when minimised)

You set these up in the Keyboard shortcuts dialog (Ctrl+K, or Options → Keyboard shortcuts). The dialog is a single list of every hotkey you can set: Enter sets the highlighted row, Del clears it (back to not set), and Escape or the Close button closes the dialog. The defaults:

You can change any of these to whatever combination you prefer. Each accepts modifiers (Ctrl, Shift, Alt) plus one ordinary key.

15. Remote control: adjusting a peer's listening volume from your end

Here's the situation this is for: you're on your laptop, listening to sound coming from your desktop, and you've got NVDA Remote open so you can drive the desktop using your laptop's keyboard. Every key you press goes to the desktop — including any volume key on the laptop, which now never reaches the laptop itself. There's no way from inside that NVDA Remote session to nudge the laptop's listening volume without breaking out of the session.

RemSound's remote control feature gives you a way around this: you set up a hotkey on the desktop (the computer your keyboard is talking to) that sends a command across the audio link, telling the laptop's RemSound to raise, lower or mute its own listening volume. You stay in NVDA Remote, and the laptop responds.

Two kinds of remote command

There are two independent sets of remote-control hotkeys, both governed by the same opt-in toggle on the receiving end. Pick whichever fits the situation, or set up both:

Both sets target the receiving computer. Neither one changes anything on the sending computer.

How to set it up

1. On the computer that should respond to remote commands (the one you're listening on — the laptop in the example): open Preferences (Ctrl+P) and tick Accept remote volume commands from peers. Save the profile (Ctrl+S) so the choice sticks. (One toggle covers both kinds of remote command.)
2. On the computer that should send remote commands (the one your keyboard is driving — the desktop in the example): open the Keyboard shortcuts dialog (Ctrl+K). Set whichever of the six remote-control rows you want:
   • Send remote volume up / down to peers — nudges the receiver's RemSound slider.
   • Send remote receive mute toggle to peers — toggles the receiver's RemSound mute.
   • Send Windows global volume up / down to peers — nudges the receiver's Windows volume.
   • Send Windows global mute toggle to peers — toggles the receiver's Windows mute.
   Use whatever key combinations you prefer (for example Ctrl+Shift+Up / Ctrl+Shift+Down for one set, and Ctrl+Alt+Up / Ctrl+Alt+Down for the other). These are global hotkeys: they work as long as RemSound is running, no matter which app is in front.
3. That's it. Press the hotkey on the desktop — the laptop responds just as it would if you'd pressed the matching key on the laptop directly, and you hear the change without leaving the NVDA Remote session. Hold the Windows-volume hotkey down for a steady ramp, since Windows' key repeat fires the step over and over.

It works both ways

The feature is symmetric: both computers can both send and accept. If you set up hotkeys on both ends and tick “Accept remote volume commands” on both ends, either side can adjust the other's volume. There's no fixed “controller” and “controlled” computer.

What it does not touch

• The RemSound app-volume commands change RemSound's receive volume slider on the target computer, not the Windows volume. So your peer can't accidentally turn down a video call or your screen reader with those.
• It only works between peers who are already connected (each one has the other ticked in their connected-peers list). The list of people you've ticked is the gatekeeper — an unticked peer can't change your volume.
• The opt-in tick is per-profile, so a setup you've marked as your “trusted home pair” can have it on while a one-off jam-session profile keeps it off.
• Remote commands travel on the same audio channel as the sound and the health check-ins (47830 by default), so there's no extra firewall rule to add.

16. Startup behaviour

Open the Startup behaviour dialog from Options → Startup behaviour (Alt+O, T). It has three independent toggles, plus a profile picker that appears when the third one is on, and a Close button. Esc closes the dialog. Each tick is saved straight away — there's no OK or Apply button.

Profile to start with (Alt+L) — the list of your saved profiles. It only shows when the third toggle is on. Pick a profile and the choice is saved straight away. Double-click a profile to pick it and close the dialog at the same time.

Combining the three for a hands-off start

1. Save a profile with the device choices, peers, and sound settings you want for “always-on” use.
2. Open Startup behaviour. Tick all three: Start minimised, Start automatically when this user logs in, and Start with a specific profile — then pick the profile you just saved.
3. Close the dialog. Reboot, or log out and back in, to test — RemSound starts itself, loads the profile, and goes straight to the tray. Sound starts flowing as soon as the peer is reachable.

17. Updating RemSound

RemSound can check for a newer version on a schedule you choose, prompt you to install it, and either ask first or do it quietly. There's also a one-press “check now” button so you don't have to wait for the timer.

Settings in Preferences

Open Options → Preferences (or Ctrl+P). The update settings sit just above the logging row:

What happens during an install

RemSound can't replace its own program file while it's running, so an install starts a small helper that finishes the job once RemSound has closed:

1. RemSound downloads the new version into a holding folder next to the running program.
2. It writes a tiny helper alongside it that watches for RemSound to close.
3. RemSound closes.
4. The helper notices, copies the new files over the install folder, deletes the holding folder, and reopens RemSound.
5. The helper deletes itself.

You'll see the window close, then reopen on the new version within a second or two. Anything that was unsaved in the old session (a profile you were partway through editing, for example) is lost — RemSound will not save it for you before installing. Save first if you've been making changes.

If an install fails

The update download is best-effort: a flaky network, a locked install folder, or a temporarily-unavailable version will pop up a message saying it couldn't finish, and leave your running version untouched. The address of the download page is in that message, so you can get the new version in a browser and install it by hand if you need to. If you installed RemSound into Program Files without giving your account permission to write to that folder, the install helper's copy step will fail too — either fix the permission or move RemSound to a folder you can write to (somewhere inside your own user folder, for instance).

If the helper's copy step itself fails — most often because Dropbox or another sync app was holding the install folder's files open when the helper tried to replace them — the helper leaves a file called update-failed.txt next to the RemSound program, with details, and leaves the new files sitting in an _update subfolder. It does not reopen the old version in that case — so the next time you start RemSound by hand, you'll either get the still-old version with that note telling you what to do, or you can copy the contents of the _update folder over the install folder yourself. The most reliable fix is: close RemSound, wait 30 seconds for Dropbox to settle, start it again, and try Help → Check for updates once more — it almost always works on the second try.

A step-by-step record of every helper run is kept in a helper log file in the install folder — useful if a failure keeps happening and you want to share it for diagnosis.

The About dialog and release notes

To see which version you're on without checking for updates, open Help → About RemSound (Alt+H, A). The dialog shows the version number and the release notes for the version you're running, in a scrollable read-only box. Close (or Esc) dismisses it.

18. Recording to a file

RemSound can save the sound passing through it to a file on your computer — useful for keeping a copy of a music session, capturing a long jam for editing later, or just saving a one-off voice exchange you want to come back to.

What gets recorded

Recording captures the sound at fully-mixed, fully-finished points: for the received side, after volume and mute have been applied (so the file matches what you hear); for the sent side, the raw captured sound just before it's packaged for sending (so the file is the same whatever codec you chose). The three source choices:

• Record all received audio — the full mix of everything coming in from connected peers. This is the default.
• Record all sent audio — what your microphones, captured speakers and ASIO inputs are sending out. Useful for checking what your collaborators are actually hearing from you.
• Record both sent and received audio — a single file with both directions mixed gently together. The right choice for capturing a complete two-way exchange.

File formats

All four formats record at a 48 kHz sample rate, and every row in the attributes list states the rate clearly so it's never in doubt.

Surviving a crash. All four formats are designed to leave a playable file behind even if RemSound crashes partway through a recording. You lose at most about 5 seconds of recently-captured sound on a crash, never the whole session.

Start and stop sound cues

RemSound plays a short ding when a recording starts and another when it stops, so you have an audible confirmation that the toggle actually took effect. The cues are record start.wav and record stop.wav in the RemSound install folder — you can drop in your own sounds to customise them, as long as you keep the same filenames.

Each cue can be turned off on its own via Preferences → Cue sounds (Alt+N). The same checklist also controls the connect and disconnect cues. The cues play through your default Windows output device, separately from the recording, so a normal RemSound recording doesn't contain the cue. The one exception: if your sending side is capturing the very same output device the cue plays through, then the cue gets captured along with everything else from that device. In that case you'll have to live with the start cue appearing in the file, unless you turn it off.

Where recordings go

By default, recordings live in <RemSound install folder>\recordings\<computer name>\. Each recording creates a new file with a name like RemSound-2026-05-19_14-30-00, so files never overwrite each other.

You can change the folder via Record → Change recordings folder. Choosing a different folder saves that location into your current profile, so it travels with the rest of your settings — switching profiles can switch your recording destination too. If a saved profile points at a folder that doesn't exist on the computer loading it, the recorder quietly falls back to the default location for that computer.

Record → Open current recordings folder opens Windows File Explorer on whatever folder is currently set, creating it on the spot if no recording has been made there yet.

Starting and stopping

There are four ways to start or stop a recording:

• Ctrl+R from anywhere in the main window — a toggle. The menu item text switches between “Start recording” and “Stop recording” to show the current state.
• Record → Start recording (or Stop, when one is in progress).
• The Start / Stop recording global hotkey — works system-wide, even when RemSound is minimised or isn't the active window. It's unset by default; set a combination in the Keyboard shortcuts dialog (Ctrl+K). See Global hotkeys.
• Closing RemSound while a recording is running finishes the file cleanly — you don't lose anything if you forget to stop it manually.

Recording happens in the background, so it doesn't affect the sound or the network. If your disk ever can't keep up, the recorder drops the oldest queued sound (never the newest) and notes it in the log; in practice you'll only see that on a fully-saturated USB stick or a very slow network drive.

Recording settings dialog

Reached via Record → Recording settings. Up to five keyboard-navigable lists, laid out left to right. FLAC's compression level has its own list, but it only shows when the file format is FLAC.

OK (Alt+O) saves your choices to the current profile. Cancel (Alt+N) or Esc discards them. Settings are saved with the profile as usual — changes here mark the profile as having unsaved changes, and you'll be asked about them on exit if you haven't saved.

19. Logs and diagnostics

If logging is turned on (the Enable logs checkbox in the Preferences dialog — Options → Preferences, or Ctrl+P — on by default), RemSound writes a log file each session into a logs folder next to the RemSound program. One file per launch.

The file contains two kinds of rows:

The Write logs now button in the Preferences dialog (Alt+W within that dialog) writes a “user requested write logs now” marker into the log, so you can find that moment in the file afterwards.

Logs are plain text and can be opened in any text editor, or in a spreadsheet. The most useful figures when something feels wrong:

• BufferMs — how much sound is queued up ready to play. It should sit close to your latency target.
• Underruns — how many times the playback reserve ran dry. Each one is a tiny click. A few per minute is normal over the internet; hundreds per second means something is broken.
• Drops — packets thrown away because the reserve overflowed. This should stay near zero in normal use.
• Heartbeat — the round-trip time to each connected peer. pending / unreachable / stale mean there's a problem.
• OpusFecRecoveries — a running total of single missing packets that Opus quietly repaired. A number that's growing means Opus is saving you from clicks. Only meaningful when an Opus codec is in use.
• OpusUnrecoveredGaps — a running total of multi-packet losses that Opus couldn't repair. Each one is an audible click. It stays at 0 on a clean connection; small numbers are normal over the internet.

20. Troubleshooting

I don't hear my friend

1. Connectivity tab: is your friend in Connected peers with a healthy round-trip time (for example “192.168.1.5: 27 ms”), not unreachable or pending?
2. Audio inputs and outputs tab: is Receive audio ticked?
3. Same tab: is at least one output device ticked, in the WASAPI or the ASIO output list?
4. Same tab: is the volume slider above zero?

My friend doesn't hear me

1. Audio inputs and outputs tab: is Send my audio ticked?
2. Same tab: is at least one capture source ticked across the three send lists?
3. If you're using a microphone: is Windows' microphone privacy setting allowing apps to use it? (Settings → Privacy → Microphone.)
4. Have they ticked your name in their Discovered peers list?

I can hear them but the sound crackles

• First, try raising Buffer smoothness by 1 or 2 on the Audio profile tab (Alt+B). It usually fixes crackles for a smaller delay cost than raising the latency does.
• Then, try raising the Audio latency value (Alt+L). Internet connections often need 30–80 ms.
• If you're using PCM, switch to Opus — Opus can repair single missing packets automatically, which PCM can't. It's much more tolerant of an unsteady network.
• If you're on Wi-Fi, try wired Ethernet — Wi-Fi adds 5–20 ms of unpredictable jitter.
• If you previously set Packet size to “Small (LAN only)” but you're now on the internet rather than a same-house network, switch it back to Standard. Small packets double the packet rate, which makes internet clicks more likely.

The sound is fine but the delay feels long

• Lower the relevant latency value on the Audio profile tab, step by step, until clicks just start, then nudge it back up by one step. With an ASIO driver chosen, this is two separate controls (one for each path).
• Or, turn on Continuous auto-tune for the path that feels slow and let RemSound find the right level.
• Lower Buffer smoothness towards 3 if you'd been running it high “just in case”.
• If only WASAPI matters for your session, set the ASIO driver picker to (none) — that turns ASIO off entirely.

The ASIO sound is grainy or constantly micro-clicks

Most likely your ASIO latency target is below the network's real-world jitter level. The receiving side fights to hold the reserve at the target, and that fight is audible. Raise ASIO latency in milliseconds (Alt+L) on the Audio profile tab to 25 ms or more and the graininess should disappear. Even pure-ASIO setups can't safely sustain a receive reserve below about 15 ms over real networks; aim higher on Wi-Fi.

I can't see my friend in Discovered peers

• If you're on the same local network: are both computers on the same Wi-Fi or Ethernet network? Some guest networks deliberately keep devices from seeing each other.
• If you're using Tailscale: type their Tailscale address into “Add peer by IP” (Connectivity tab, Alt+A) once. After that, both sides see each other automatically.
• Check that Windows Firewall isn't blocking RemSound. The first launch usually asks; if you said no, you'll need to allow it by hand.

A peer rebooted or changed address and the sound didn't come back

RemSound follows a peer to its new address on its own. If the address you connected to stops responding but the same peer is still reaching you from a different address on your network — because they rebooted onto a new address, for example — RemSound re-points to the live address within a few seconds and the sound resumes without you doing anything. If it doesn't recover, the peer is genuinely unreachable (off, asleep, or a firewall is blocking the new path).

One side says “unreachable” even though sound is flowing

The health check-ins use the same channel as the audio, so if the sound gets through, the check-ins should too. If one side shows “unreachable” while the sound plays fine, make sure both computers are running the same version of RemSound — an older version on either end can speak a slightly different check-in language.

My other audio went silent or crackly when I selected an ASIO driver

You probably picked Realtek ASIO. It's a generic driver, not tied to Realtek hardware, and it tends to grab whatever Windows treats as the default sound device — usually the same one your screen reader is using. Set the ASIO driver picker back to (none), or pick a different ASIO driver.

The device list shows old devices that are no longer plugged in

RemSound refreshes its lists every second. If a device has really been unplugged it should disappear within a few seconds. If it lingers, restart RemSound — Windows' own device list occasionally needs a nudge.

21. Glossary