From 4e576afebd40842145d765c25322767917c067ed Mon Sep 17 00:00:00 2001
From: Ovgodd <c.gromoff@gmail.com>
Date: Thu, 1 Oct 2026 10:16:35 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B(frontend)=20omit=20the=20default?=
 =?UTF-8?q?=20speaker=20id=20sent=20to=20LiveKit?=
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Content-Type: text/plain; charset=UTF-8
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Firefox rejects setSinkId('default') when a remote audio track
is attached. Omit that id and only send a real device id.
---
 CHANGELOG.md                                          |  1 +
 .../src/features/analytics/exceptionFilters.ts        |  4 ++++
 .../src/features/rooms/components/Conference.tsx      |  3 ++-
 .../rooms/utils/resolveAudioOutputDeviceId.ts         | 11 +++++++++++
 4 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 src/frontend/src/features/rooms/utils/resolveAudioOutputDeviceId.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bfd008d74..742bd0e2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ and this project adheres to
 
 ### Fixed
 
+- 🐛(frontend) omit the default speaker id sent to LiveKit
 - 🐛(frontend) enforce recording-mode permissions on the checkboxes
 - 🔒️(agents) fix util-linux CVEs reported by Cyberwatch
 
diff --git a/src/frontend/src/features/analytics/exceptionFilters.ts b/src/frontend/src/features/analytics/exceptionFilters.ts
index aa97d5025..f8936d2fa 100644
--- a/src/frontend/src/features/analytics/exceptionFilters.ts
+++ b/src/frontend/src/features/analytics/exceptionFilters.ts
@@ -8,6 +8,10 @@ const IGNORED_EXCEPTION_PATTERNS = [
   // the close reason is already logged by the SDK.
   // See: https://github.com/livekit/client-sdk-js/issues/2062
   /^Event captured as exception with keys: isTrusted$/,
+  // LiveKit logs a rejected setSinkId on remote audio attach and already
+  // swallows it. capture_console_errors turns that log into an exception
+  // and stringifies the real error as [object Object].
+  /^Failed to set sink id on remote audio track/,
 ]
 
 const shouldIgnoreException = (value: unknown): boolean =>
diff --git a/src/frontend/src/features/rooms/components/Conference.tsx b/src/frontend/src/features/rooms/components/Conference.tsx
index 2877015e1..6901adf9d 100644
--- a/src/frontend/src/features/rooms/components/Conference.tsx
+++ b/src/frontend/src/features/rooms/components/Conference.tsx
@@ -45,6 +45,7 @@ import { userStore } from '@/stores/user'
 import { WatchMediaDeviceErrors } from './WatchMediaDeviceErrors'
 import { MeetDevtools } from '@/features/devtools'
 import { VOICE_AUDIO_CONSTRAINTS } from '@/features/rooms/livekit/utils/constants'
+import { resolveAudioOutputDeviceId } from '@/features/rooms/utils/resolveAudioOutputDeviceId'
 
 export const Conference = ({
   roomId,
@@ -120,7 +121,7 @@ export const Conference = ({
         ...VOICE_AUDIO_CONSTRAINTS,
       },
       audioOutput: {
-        deviceId: userConfig.audioOutputDeviceId ?? undefined,
+        deviceId: resolveAudioOutputDeviceId(userConfig.audioOutputDeviceId),
       },
     }
     // do not rely on the userConfig object directly as its reference may change on every render
diff --git a/src/frontend/src/features/rooms/utils/resolveAudioOutputDeviceId.ts b/src/frontend/src/features/rooms/utils/resolveAudioOutputDeviceId.ts
new file mode 100644
index 000000000..b417efdee
--- /dev/null
+++ b/src/frontend/src/features/rooms/utils/resolveAudioOutputDeviceId.ts
@@ -0,0 +1,11 @@
+/**
+ * `'default'` means "use the system output". Firefox has no device with that
+ * id, so LiveKit's setSinkId('default') rejects on every remote audio attach.
+ * Omit it and the browser keeps the OS default, which is the same result.
+ */
+export const resolveAudioOutputDeviceId = (
+  deviceId: string | undefined
+): string | undefined => {
+  if (!deviceId || deviceId === 'default') return undefined
+  return deviceId
+}