Fullfører oppgave 16.4: Delt mixer-kontroll via SpacetimeDB

Implementerer sanntids mixer-synkronisering mellom alle deltakere i et LiveKit-rom via SpacetimeDB. Når én deltaker justerer gain eller muter en kanal, oppdateres alle klienters Web Audio-graf og UI umiddelbart. SpacetimeDB-modul (Rust): - MixerChannel-tabell med room_id/target_user_id-indekser - Reducers: set_gain (clamped 0.0-1.5), set_mute, toggle_effect, create/delete_mixer_channel, set_mixer_role (editor/viewer) - Viewer-sjekk i reducers — viewer kan ikke endre andres kanaler - Opprydding av mixer-kanaler i close_live_room og clear_all Frontend (SvelteKit): - mixerChannelStore med reaktive callbacks og room_id-indeks - MixerTrait leser delt state fra STDB, skriver endringer via reducers - suppressRemoteSync-flagg forhindrer feedback-loop ved egne endringer - Viewer-modus: disabled sliders/knapper for låste deltakere - Visuell (V)-indikator for viewer-kanaler Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-18 05:08:23 +00:00 · 2026-03-18 05:08:23 +00:00 · 453ec4fb59
commit 453ec4fb59
parent de498f26a1
17 changed files with 862 additions and 41 deletions
--- a/docs/features/lydmixer.md
+++ b/docs/features/lydmixer.md
@ -0,0 +1,249 @@
+# Feature: Lydmixer (Virtuelt studioverktøy)
+**Filsti:** `docs/features/lydmixer.md`
+
+## 1. Konsept
+En nettleserbasert lydmixer inspirert av RødeCaster Pro II. Gir programledere
+og møtedeltakere kontroll over lydnivåer, lydeffekter og stemmeeffekter
+direkte i Synops — uten behov for ekstern maskinvare.
+
+Bygget på Web Audio API med LiveKit-integrasjon. Alle lydstrømmer (mikrofon,
+remote-deltakere, sound pads) rutes gjennom en Web Audio-graf som gir
+per-kanal prosessering før avspilling.
+
+## 2. Brukeropplevelse
+1. Brukeren åpner studioet/møterommet og kobler seg til LiveKit-rommet.
+2. I bunnen av skjermen vises en **mixerstripe** med én kanal per deltaker.
+3. Hver kanal har: volumslider, mute-knapp, og valgfri effektkjede.
+4. Over mixeren ligger et **pad-brett** med konfigurerbare lydeffekter.
+5. En **effektvelger** per kanal lar brukeren slå av/på stemmeeffekter
+   (monster, robot) og lydbehandling (fat bottom, exciter, sparkle).
+
+## 3. Kjernekomponenter
+
+### 3.1 Kanalstripe (per deltaker)
+Hver LiveKit-deltaker får en dedikert kanalstripe i mixeren:
+
+| Element | Funksjon | Web Audio |
+|---|---|---|
+| **Volumslider** | Visuell fader 0–150% | `GainNode` (0.0–1.5) |
+| **Nød-mute** | Stor, rød knapp — umiddelbar demping | `gain.setValueAtTime(0, now)` |
+| **Nivåmeter** | VU-meter som viser live lydnivå | `AnalyserNode` → canvas |
+| **Navnelabel** | Deltakerens display_name | Fra LiveKit participant |
+
+### 3.2 Effektkjede (per kanal, valgfri)
+Hver kanal kan ha en kjede av prosesseringsmoduler som slås av/på individuelt:
+
+| Effekt | Beskrivelse | Web Audio |
+|---|---|---|
+| **Fat bottom** | Lavfrekvent fylde (~200Hz, +6–12dB) | `BiquadFilterNode` lowshelf |
+| **Exciter** | Harmonisk tilstedeværelse (3–5kHz) | `WaveShaperNode` + highshelf |
+| **Sparkle** | Høyfrekvent luft (~10–16kHz, +3–6dB) | `BiquadFilterNode` highshelf |
+| **Monsterstemme** | Pitch ned 4–8 halvtoner | `AudioWorkletNode` (phase vocoder) |
+| **Robotstemme** | Metallisk ring-modulasjon | `OscillatorNode` → `GainNode.gain` |
+
+Signalflyt per kanal:
+```
+Kilde → HighPass(80Hz) → FatBottom → Exciter → Sparkle → PitchShift → GainNode(fader) → Master
+```
+
+### 3.3 Sound Pads
+Et grid med konfigurerbare lyd-pads (inspirert av RødeCaster Pro II sine 8×8 pads):
+
+| Egenskap | Detalj |
+|---|---|
+| **Layout** | Grid, f.eks. 4×2 (utvidbart) |
+| **Avspilling** | Trykk → spill fra start til slutt |
+| **Lydkilde** | Forhåndslastede `AudioBuffer` fra CAS |
+| **Volum** | Egen `GainNode` per pad |
+| **Synkronisering** | LiveKit Data Message → alle klienter spiller samtidig |
+| **Konfigurasjon** | Velg lydfil, farge, label per pad |
+
+Eksempler på standard-pads: jingle/intro, applaus, latter, dramatisk pause,
+"breaking news"-sting, rim shot, sad trombone, airhorn.
+
+### 3.4 Delt mixer-kontroll (flerbruker)
+Alle deltakere i rommet kan se og bruke mixeren samtidig. Mixer-state
+synkroniseres i sanntid via SpacetimeDB, slik at volumendringer, mutes,
+effekttogles og pad-avspilling reflekteres hos alle klienter umiddelbart.
+
+| Element | Synkronisering |
+|---|---|
+| **Volumslider** | STDB: `MixerChannel`-tabell med `gain`-verdi per kanal |
+| **Mute** | STDB: `is_muted` boolean per kanal |
+| **Effekt av/på** | STDB: `active_effects` JSON per kanal |
+| **Pad-trigger** | LiveKit Data Message (lav latens) |
+| **Pad-konfig** | Node metadata (persistent, sjelden endring) |
+
+**Tilgangsnivåer:**
+- **Full kontroll** (default): alle deltakere kan justere alle kanaler,
+  trigge pads og endre effekter. Tilsvarer at alle sitter rundt samme
+  RødeCaster.
+- **Begrenset**: eier/admin kan låse enkeltdeltakere til kun "viewer" —
+  de ser mixeren live men kan ikke interagere. Bruker eksisterende
+  rolle-system (owner/admin/member-edges).
+
+**Konflikthåndtering:** Last-write-wins. Volumslidere er kontinuerlige
+verdier som oppdateres via STDB-reducers. Ved samtidig endring av samme
+kanal vinner siste skriving — i praksis uproblematisk fordi endringer
+er visuelt synlige for alle og deltakerne koordinerer naturlig.
+
+**SpacetimeDB-tabeller:**
+
+```rust
+#[spacetimedb::table(accessor = mixer_channel, public)]
+pub struct MixerChannel {
+    #[primary_key]
+    pub id: String,              // "{room_id}:{target_user_id}"
+    pub room_id: String,         // "communication_{node_uuid}"
+    pub target_user_id: String,  // hvem kanalen tilhører
+    pub gain: f64,               // 0.0–1.5
+    pub is_muted: bool,
+    pub active_effects: String,  // JSON: {"fat_bottom": true, "robot": false, ...}
+    pub role: String,            // "editor" | "viewer" — tilgangskontroll per kanal
+    pub updated_by: String,      // hvem som sist endret
+    pub updated_at: Timestamp,
+}
+```
+
+**STDB Reducers:**
+- `create_mixer_channel(room_id, target_user_id, updated_by)` — idempotent opprettelse
+- `set_gain(room_id, target_user_id, gain, updated_by)` — clamped 0.0–1.5, viewer-sjekk
+- `set_mute(room_id, target_user_id, is_muted, updated_by)` — viewer-sjekk
+- `toggle_effect(room_id, target_user_id, effect_name, updated_by)` — JSON-toggle
+- `delete_mixer_channel(room_id, target_user_id)` — opprydding ved disconnect
+- `set_mixer_role(room_id, target_user_id, role, updated_by)` — sett editor/viewer
+
+Mixer-kanaler ryddes automatisk ved `close_live_room` og `clear_all`.
+
+### 3.5 Master-seksjon
+| Element | Funksjon |
+|---|---|
+| **Master fader** | Samlet utgangsnivå |
+| **Master mute** | Demper all lyd |
+| **Master VU** | Stereo nivåmeter for utgangen |
+
+## 4. Teknisk arkitektur
+
+### 4.1 Web Audio-graf
+```
+                    ┌─────────────────────────────────┐
+                    │         AudioContext             │
+                    │                                  │
+  Remote Track 1 ──→ MediaStreamSource → EffektKjede → GainNode ─┐
+  Remote Track 2 ──→ MediaStreamSource → EffektKjede → GainNode ─┤
+  Lokal mikrofon ──→ MediaStreamSource → EffektKjede → GainNode ─┼→ MasterGain → destination
+  Sound Pad      ──→ AudioBufferSource ─────────────→ GainNode ─┘
+                    │                                  │
+                    └─────────────────────────────────┘
+```
+
+### 4.2 LiveKit-integrasjon
+- **Innkommende lyd:** Deaktiver LiveKit sin auto-attach av `<audio>`-elementer.
+  Hent `MediaStreamTrack` fra remote participant, opprett
+  `MediaStreamSourceNode`, rut gjennom Web Audio-kjeden.
+- **Utgående lyd:** Mikrofon → Web Audio-kjede → `MediaStreamAudioDestinationNode`
+  → publiser den prosesserte tracken via LiveKit.
+- **Sound pads over nett:** Send LiveKit Data Message (reliable) med pad-ID
+  og tidsstempel. Alle klienter trigge samme pad lokalt. Akseptabel synk: <50ms.
+
+### 4.3 Stemmeeffekter (AudioWorklet)
+Pitch-shifting (monsterstemme) krever en `AudioWorkletProcessor` som kjører
+på lyd-tråden:
+- **Algoritme:** Phase vocoder med identity phase locking
+- **Bibliotek:** Vurder `phaze` eller `SoundTouchJS` AudioWorklet
+- **Latens:** ~20–40ms avhengig av FFT-vindu (1024–2048 samples ved 48kHz)
+- **Parametere:** Pitch-faktor (0.5 = oktav ned, 0.7 = monster, 1.0 = normal)
+
+Robot-stemme bruker ring-modulasjon — ingen AudioWorklet nødvendig:
+- `OscillatorNode` (sinus, 50–200Hz) kobles til `GainNode.gain` AudioParam
+- Stemmekilden kobles til samme `GainNode`
+- Resultatet er metallisk, Dalek-aktig stemme
+
+### 4.4 Pad-konfigurasjon (lagring)
+Sound pads lagres i samlingsnoden sin metadata:
+```json
+{
+  "traits": ["recording", "mixer"],
+  "mixer": {
+    "pads": [
+      { "label": "Jingle", "cas_hash": "abc123...", "color": "#FF6B6B" },
+      { "label": "Applaus", "cas_hash": "def456...", "color": "#4ECDC4" }
+    ]
+  }
+}
+```
+
+## 5. Avhengigheter
+
+| Avhengighet | Type | Lisens | Formål |
+|---|---|---|---|
+| `livekit-client` | npm | Apache-2.0 | WebRTC-klient for LiveKit |
+| Web Audio API | nettleser | — | All lydprosessering (innebygd) |
+| CAS | eksisterende | — | Lagring av pad-lydfiler |
+
+**Ingen betalte tjenester.** All lydprosessering skjer lokalt i nettleseren
+via Web Audio API. Stemmeeffekter (robot, monster) og EQ (fat bottom, exciter,
+sparkle) bygges med innebygde Web Audio-noder og en egenutviklet
+`AudioWorkletProcessor` for pitch shifting. Phase vocoder-algoritmen er
+veldokumentert og implementeres direkte — ingen tredjepartslisens nødvendig.
+
+## 6. Node/trait-integrasjon
+Lydmixeren aktiveres via `mixer`-traitet på en samlings-node. Krever at
+`recording`-traitet også er aktivt (LiveKit-avhengighet).
+
+- **Trait:** `mixer` (kategori: Lyd & video)
+- **Frontend:** MixerTrait-komponent i samlingssiden
+- **Backend:** Ingen nye endepunkter — bruker eksisterende LiveKit token-generering
+  og CAS for pad-lydfiler
+
+## 7. Avgrensning
+- Mixeren er for **live-bruk**, ikke postproduksjon/redigering
+- Effektene prosesseres **lokalt** i nettleseren — ikke på serveren
+- Hver bruker kontrollerer sin egen mixer (personlig mix)
+- Pad-synkronisering er best-effort (~50ms) — akseptabelt for lydeffekter
+- Støtter ikke multitrack-opptak (det er en separat feature)
+
+## 8. Utviklingsfaser
+
+### Fase A: Grunnleggende mixer (MVP)
+- [x] `livekit-client` integrasjon i frontend (koble til rom, vise deltakere)
+- [x] Web Audio-graf: MediaStreamSource per remote track → GainNode → destination
+- [x] Kanalstripe-UI: volumslider + mute-knapp per deltaker
+- [x] VU-meter (AnalyserNode → canvas/CSS)
+- [x] Master fader og master mute
+
+### Fase B: Delt mixer-kontroll
+- [x] SpacetimeDB: `MixerChannel`-tabell + reducers (set_gain, set_mute, toggle_effect, set_mixer_role)
+- [x] Frontend abonnerer på mixer-state, oppdaterer Web Audio-graf ved endringer
+- [x] Visuell feedback: alle ser sliders bevege seg i sanntid
+- [x] Tilgangskontroll: eier/admin kan sette deltaker til "viewer" (kun observere)
+
+### Fase C: Sound Pads
+- [ ] Pad-grid UI (4×2 grid med fargede knapper)
+- [ ] Last lydfiler fra CAS → AudioBuffer
+- [ ] Avspilling ved trykk (AudioBufferSourceNode)
+- [ ] Pad-konfigurasjon: velg lydfil, farge, label (lagres i node metadata)
+- [ ] LiveKit Data Message for synkronisert avspilling på tvers av deltakere
+
+### Fase D: Lydbehandling (EQ)
+- [ ] Fat bottom (lowshelf filter)
+- [ ] Sparkle (highshelf filter)
+- [ ] Exciter (WaveShaperNode + filter)
+- [ ] Per-kanal av/på-toggles for hver effekt (synkronisert via STDB)
+- [ ] Preset-konfigurasjon (f.eks. "Podcast-stemme", "Radio-stemme")
+
+### Fase E: Stemmeeffekter
+- [ ] Robotstemme (ring-modulasjon med OscillatorNode)
+- [ ] Monsterstemme (pitch shift via egenutviklet AudioWorklet)
+- [ ] Effektvelger-UI per kanal
+- [ ] Parameterjustering (pitch-faktor, oscillator-frekvens)
+
+## 9. Instruks for Claude Code
+- Lydmixeren er **ren frontend** — ingen nye Rust-endepunkter nødvendig
+- Bruk Web Audio API, IKKE `<audio>`-elementer for prosessering
+- AudioWorklet for pitch shifting — aldri ScriptProcessorNode (deprecated)
+- `AudioContext` må opprettes fra brukergest (klikk/tap) — nettleserkrav
+- Pad-lydfiler lagres i CAS via eksisterende `upload_media` intention
+- Pad-konfigurasjon i samlingsnoden sin `metadata.mixer`-nøkkel
+- Stemmeeffekter prosesseres lokalt — ikke send prosessert lyd over LiveKit
+  med mindre brukeren eksplisitt vil at andre skal høre effekten
--- a/frontend/src/lib/components/traits/MixerTrait.svelte
+++ b/frontend/src/lib/components/traits/MixerTrait.svelte
@ -1,5 +1,7 @@
 <script lang="ts">
 	import type { Node } from '$lib/spacetime';
+	import { edgeStore, nodeStore, mixerChannelStore, stdb } from '$lib/spacetime';
+	import type { MixerChannel } from '$lib/spacetime';
 	import TraitPanel from './TraitPanel.svelte';
 	import {
 		getStatus,
@ -16,7 +18,6 @@
 		muteChannel,
 		unmuteChannel,
 		setMasterGain,
-		getMasterGain,
 		muteMaster,
 		unmuteMaster,
 		getChannelIdentities,
@ -34,10 +35,8 @@
 	// LiveKit state
 	let participants: LiveKitParticipant[] = $state([]);
 	let localIdentity: string = $state('');
-	let isConnected = $derived(getStatus() === 'connected');

-	// Per-channel UI state: tracks gain values and mute state for UI
-	let channelStates: Map<string, { gain: number; muted: boolean }> = $state(new Map());
+	// Master state (local only — master is per-client, not shared)
 	let masterState = $state({ gain: 1.0, muted: false });

 	// VU meter levels (updated via animation frame)
@ -47,23 +46,84 @@
 	// Animation frame for VU meters
 	let animFrameId: number | null = null;

+	// Flag to suppress STDB sync feedback for own changes
+	let suppressRemoteSync = false;
+
+	// Derive room_id from the collection's communication node
+	// Pattern: "communication_{communication_node_id}"
+	const roomId = $derived.by(() => {
+		for (const edge of edgeStore.byTarget(collection.id)) {
+			if (edge.edgeType !== 'belongs_to') continue;
+			const node = nodeStore.get(edge.sourceId);
+			if (node && node.nodeKind === 'communication') {
+				return `communication_${node.id}`;
+			}
+		}
+		for (const edge of edgeStore.bySource(collection.id)) {
+			if (edge.edgeType !== 'has_channel') continue;
+			const node = nodeStore.get(edge.targetId);
+			if (node && node.nodeKind === 'communication') {
+				return `communication_${node.id}`;
+			}
+		}
+		return null;
+	});
+
+	// Get shared mixer channels from STDB for this room
+	const sharedChannels = $derived(roomId ? mixerChannelStore.byRoom(roomId) : []);
+
+	// Check if the local user is a viewer (read-only)
+	const localRole = $derived.by(() => {
+		if (!roomId || !localIdentity) return 'editor';
+		const ch = mixerChannelStore.byParticipant(roomId, localIdentity);
+		return ch?.role ?? 'editor';
+	});
+
+	const isViewer = $derived(localRole === 'viewer');
+
+	// Get channel state from STDB shared state, fallback to local
+	function getSharedState(identity: string): { gain: number; muted: boolean } {
+		if (!roomId) return { gain: getChannelGain(identity), muted: false };
+		const ch = mixerChannelStore.byParticipant(roomId, identity);
+		if (ch) return { gain: ch.gain, muted: ch.isMuted };
+		return { gain: getChannelGain(identity), muted: false };
+	}
+
 	$effect(() => {
 		const unsub = subscribe(() => {
 			participants = getParticipants();
 			localIdentity = getLocalIdentity();

-			// Sync channel states for new participants
+			// Ensure STDB mixer channels exist for new participants
 			const activeIdentities = getChannelIdentities();
-			for (const id of activeIdentities) {
-				if (!channelStates.has(id)) {
-					channelStates.set(id, { gain: getChannelGain(id), muted: false });
-					channelStates = new Map(channelStates);
+			const conn = stdb.getConnection();
+			if (conn && roomId) {
+				for (const id of activeIdentities) {
+					const existing = mixerChannelStore.byParticipant(roomId, id);
+					if (!existing) {
+						conn.reducers.createMixerChannel({ roomId, targetUserId: id, updatedBy: localIdentity });
+					}
 				}
 			}
 		});
 		return unsub;
 	});

+	// Sync Web Audio graph when STDB mixer state changes from other clients
+	$effect(() => {
+		if (suppressRemoteSync) return;
+		for (const ch of sharedChannels) {
+			// Apply shared gain/mute to Web Audio graph
+			if (ch.isMuted) {
+				muteChannel(ch.targetUserId);
+			} else {
+				setChannelGain(ch.targetUserId, ch.gain);
+				// Ensure unmuted in Web Audio if was previously muted
+				unmuteChannel(ch.targetUserId, ch.gain);
+			}
+		}
+	});
+
 	// Start/stop VU meter animation loop based on connection
 	$effect(() => {
 		if (getStatus() === 'connected') {
@ -77,7 +137,6 @@
 	function startVuLoop() {
 		if (animFrameId !== null) return;
 		function tick() {
-			// Read levels for all channels
 			const newLevels = new Map<string, ChannelLevels>();
 			for (const id of getChannelIdentities()) {
 				const l = getChannelLevels(id);
@ -97,32 +156,38 @@
 		}
 	}

-	// Channel controls
+	// Channel controls — update local Web Audio AND broadcast via STDB
 	function handleGainChange(identity: string, value: number) {
 		setChannelGain(identity, value);
-		const state = channelStates.get(identity);
-		if (state) {
-			state.gain = value;
-			state.muted = false;
-			channelStates = new Map(channelStates);
+
+		const conn = stdb.getConnection();
+		if (conn && roomId) {
+			suppressRemoteSync = true;
+			conn.reducers.setGain({ roomId, targetUserId: identity, gain: value, updatedBy: localIdentity });
+			// Release suppress after a tick to allow STDB callback to settle
+			requestAnimationFrame(() => { suppressRemoteSync = false; });
 		}
 	}

 	function handleEmergencyMute(identity: string) {
-		const state = channelStates.get(identity);
-		if (!state) return;
+		const state = getSharedState(identity);
+		const newMuted = !state.muted;

-		if (state.muted) {
-			unmuteChannel(identity, state.gain);
-			state.muted = false;
-		} else {
+		if (newMuted) {
 			muteChannel(identity);
-			state.muted = true;
+		} else {
+			unmuteChannel(identity, state.gain);
+		}
+
+		const conn = stdb.getConnection();
+		if (conn && roomId) {
+			suppressRemoteSync = true;
+			conn.reducers.setMute({ roomId, targetUserId: identity, isMuted: newMuted, updatedBy: localIdentity });
+			requestAnimationFrame(() => { suppressRemoteSync = false; });
 		}
-		channelStates = new Map(channelStates);
 	}

-	// Master controls
+	// Master controls (local only — not shared across clients)
 	function handleMasterGainChange(value: number) {
 		setMasterGain(value);
 		masterState.gain = value;
@ -139,10 +204,18 @@
 		}
 	}

+	// Access control: set a participant to viewer mode
+	function handleSetRole(identity: string, role: 'editor' | 'viewer') {
+		const conn = stdb.getConnection();
+		if (conn && roomId) {
+			conn.reducers.setMixerRole({ roomId, targetUserId: identity, role, updatedBy: localIdentity });
+		}
+	}
+
 	// VU meter helpers
 	function vuPercent(levels: ChannelLevels | null | undefined): number {
 		if (!levels) return 0;
-		return Math.min(100, levels.rms * 100 * 3); // scale up for visibility
+		return Math.min(100, levels.rms * 100 * 3);
 	}

 	function vuColor(levels: ChannelLevels | null | undefined): string {
@ -164,6 +237,12 @@
 		return Math.round(gain * 100);
 	}

+	function channelRole(identity: string): string {
+		if (!roomId) return 'editor';
+		const ch = mixerChannelStore.byParticipant(roomId, identity);
+		return ch?.role ?? 'editor';
+	}
+
 	// Channels that have actual audio (from mixer.ts)
 	const activeChannels = $derived(getChannelIdentities());
 	// Show participants that are in the room, with mixer channels where available
@ -187,17 +266,23 @@
 			<!-- Channel strips -->
 			<div class="space-y-2 sm:space-y-3">
 				{#each displayChannels as identity (identity)}
-					{@const state = channelStates.get(identity)}
+					{@const state = getSharedState(identity)}
 					{@const levels = channelLevels.get(identity)}
-					{@const isMuted = state?.muted ?? false}
-					{@const gain = state?.gain ?? 1.0}
+					{@const isMuted = state.muted}
+					{@const gain = state.gain}
+					{@const role = channelRole(identity)}
+					{@const isChannelViewer = role === 'viewer'}

-					<div class="rounded-lg border border-gray-100 bg-gray-50 p-2 sm:p-3">
+					<div class="rounded-lg border border-gray-100 bg-gray-50 p-2 sm:p-3
+						{isChannelViewer ? 'opacity-60' : ''}">
 						<!-- Mobile: stacked / Desktop: horizontal -->
 						<div class="flex flex-col gap-2 sm:flex-row sm:items-center sm:gap-3">
-							<!-- Name label -->
-							<span class="text-xs font-medium text-gray-700 truncate sm:w-28 sm:flex-shrink-0">
+							<!-- Name label with role indicator -->
+							<span class="text-xs font-medium text-gray-700 truncate sm:w-28 sm:flex-shrink-0 flex items-center gap-1">
 								{displayName(identity)}
+								{#if isChannelViewer}
+									<span class="text-[10px] text-gray-400 uppercase" title="Kun visning">(V)</span>
+								{/if}
 							</span>

 							<!-- VU meter -->
@ -217,7 +302,7 @@
 									step="0.01"
 									value={gain}
 									oninput={(e) => handleGainChange(identity, parseFloat((e.target as HTMLInputElement).value))}
-									disabled={isMuted}
+									disabled={isMuted || (isViewer && identity !== localIdentity)}
 									class="flex-1 h-2 accent-indigo-600 disabled:opacity-40"
 								/>
 								<span class="text-xs text-gray-500 w-10 text-right tabular-nums flex-shrink-0">
@ -228,10 +313,12 @@
 							<!-- Emergency mute button -->
 							<button
 								onclick={() => handleEmergencyMute(identity)}
+								disabled={isViewer && identity !== localIdentity}
 								class="flex-shrink-0 rounded-lg px-3 py-2 text-xs font-bold uppercase tracking-wide transition-colors
 									{isMuted
 										? 'bg-red-600 text-white shadow-md hover:bg-red-700'
-										: 'bg-red-100 text-red-700 hover:bg-red-200'}"
+										: 'bg-red-100 text-red-700 hover:bg-red-200'}
+									disabled:opacity-40 disabled:cursor-not-allowed"
 								title={isMuted ? 'Slå på lyd' : 'Nøddemp'}
 							>
 								{isMuted ? 'DEMPET' : 'DEMP'}
--- a/frontend/src/lib/spacetime/connection.svelte.ts
+++ b/frontend/src/lib/spacetime/connection.svelte.ts
@ -64,6 +64,7 @@ function connect(token?: string): DbConnection {
 					'SELECT * FROM node',
 					'SELECT * FROM edge',
 					'SELECT * FROM node_access',
+					'SELECT * FROM mixer_channel',
 				]);
 		})
 		.onConnectError((_ctx: ErrorContext, err: Error) => {
--- a/frontend/src/lib/spacetime/index.ts
+++ b/frontend/src/lib/spacetime/index.ts
@ -6,5 +6,5 @@
 */

 export { stdb, connectionState } from './connection.svelte';
-export { nodeStore, edgeStore, nodeAccessStore, nodeVisibility } from './stores.svelte';
-export type { Node, Edge, NodeAccess } from './module_bindings/types';
+export { nodeStore, edgeStore, nodeAccessStore, mixerChannelStore, nodeVisibility } from './stores.svelte';
+export type { Node, Edge, NodeAccess, MixerChannel } from './module_bindings/types';
--- a/frontend/src/lib/spacetime/module_bindings/create_mixer_channel_reducer.ts
+++ b/frontend/src/lib/spacetime/module_bindings/create_mixer_channel_reducer.ts
@ -0,0 +1,17 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default {
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+  updatedBy: __t.string(),
+};
--- a/frontend/src/lib/spacetime/module_bindings/delete_mixer_channel_reducer.ts
+++ b/frontend/src/lib/spacetime/module_bindings/delete_mixer_channel_reducer.ts
@ -0,0 +1,16 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default {
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+};
--- a/frontend/src/lib/spacetime/module_bindings/index.ts
+++ b/frontend/src/lib/spacetime/module_bindings/index.ts
@ -44,11 +44,18 @@ import DeleteNodeAccessForSubjectReducer from "./delete_node_access_for_subject_
 import UpdateEdgeReducer from "./update_edge_reducer";
 import UpdateNodeReducer from "./update_node_reducer";
 import UpsertNodeAccessReducer from "./upsert_node_access_reducer";
+import CreateMixerChannelReducer from "./create_mixer_channel_reducer";
+import SetGainReducer from "./set_gain_reducer";
+import SetMuteReducer from "./set_mute_reducer";
+import ToggleEffectReducer from "./toggle_effect_reducer";
+import DeleteMixerChannelReducer from "./delete_mixer_channel_reducer";
+import SetMixerRoleReducer from "./set_mixer_role_reducer";

 // Import all procedure arg schemas

 // Import all table schema definitions
 import EdgeRow from "./edge_table";
+import MixerChannelRow from "./mixer_channel_table";
 import NodeRow from "./node_table";
 import NodeAccessRow from "./node_access_table";

@ -73,6 +80,23 @@ const tablesSchema = __schema({
      { name: 'edge_id_key', constraint: 'unique', columns: ['id'] },
    ],
  }, EdgeRow),
+  mixer_channel: __table({
+    name: 'mixer_channel',
+    indexes: [
+      { accessor: 'id', name: 'mixer_channel_id_idx_btree', algorithm: 'btree', columns: [
+        'id',
+      ] },
+      { accessor: 'room_id', name: 'mixer_channel_room_id_idx_btree', algorithm: 'btree', columns: [
+        'roomId',
+      ] },
+      { accessor: 'target_user_id', name: 'mixer_channel_target_user_id_idx_btree', algorithm: 'btree', columns: [
+        'targetUserId',
+      ] },
+    ],
+    constraints: [
+      { name: 'mixer_channel_id_key', constraint: 'unique', columns: ['id'] },
+    ],
+  }, MixerChannelRow),
  node: __table({
    name: 'node',
    indexes: [
@ -115,6 +139,12 @@ const reducersSchema = __reducers(
  __reducerSchema("update_edge", UpdateEdgeReducer),
  __reducerSchema("update_node", UpdateNodeReducer),
  __reducerSchema("upsert_node_access", UpsertNodeAccessReducer),
+  __reducerSchema("create_mixer_channel", CreateMixerChannelReducer),
+  __reducerSchema("set_gain", SetGainReducer),
+  __reducerSchema("set_mute", SetMuteReducer),
+  __reducerSchema("toggle_effect", ToggleEffectReducer),
+  __reducerSchema("delete_mixer_channel", DeleteMixerChannelReducer),
+  __reducerSchema("set_mixer_role", SetMixerRoleReducer),
 );

 /** The schema information for all procedures in this module. This is defined the same way as the procedures would have been defined in the server. */
--- a/frontend/src/lib/spacetime/module_bindings/mixer_channel_table.ts
+++ b/frontend/src/lib/spacetime/module_bindings/mixer_channel_table.ts
@ -0,0 +1,23 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default __t.row({
+  id: __t.string().primaryKey(),
+  roomId: __t.string().name("room_id"),
+  targetUserId: __t.string().name("target_user_id"),
+  gain: __t.f64(),
+  isMuted: __t.bool().name("is_muted"),
+  activeEffects: __t.string().name("active_effects"),
+  role: __t.string(),
+  updatedBy: __t.string().name("updated_by"),
+  updatedAt: __t.timestamp().name("updated_at"),
+});
--- a/frontend/src/lib/spacetime/module_bindings/set_gain_reducer.ts
+++ b/frontend/src/lib/spacetime/module_bindings/set_gain_reducer.ts
@ -0,0 +1,18 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default {
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+  gain: __t.f64(),
+  updatedBy: __t.string(),
+};
--- a/frontend/src/lib/spacetime/module_bindings/set_mixer_role_reducer.ts
+++ b/frontend/src/lib/spacetime/module_bindings/set_mixer_role_reducer.ts
@ -0,0 +1,18 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default {
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+  role: __t.string(),
+  updatedBy: __t.string(),
+};
--- a/frontend/src/lib/spacetime/module_bindings/set_mute_reducer.ts
+++ b/frontend/src/lib/spacetime/module_bindings/set_mute_reducer.ts
@ -0,0 +1,18 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default {
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+  isMuted: __t.bool(),
+  updatedBy: __t.string(),
+};
--- a/frontend/src/lib/spacetime/module_bindings/toggle_effect_reducer.ts
+++ b/frontend/src/lib/spacetime/module_bindings/toggle_effect_reducer.ts
@ -0,0 +1,18 @@
+// THIS FILE IS AUTOMATICALLY GENERATED BY SPACETIMEDB. EDITS TO THIS FILE
+// WILL NOT BE SAVED. MODIFY TABLES IN YOUR MODULE SOURCE CODE INSTEAD.
+
+/* eslint-disable */
+/* tslint:disable */
+import {
+  TypeBuilder as __TypeBuilder,
+  t as __t,
+  type AlgebraicTypeType as __AlgebraicTypeType,
+  type Infer as __Infer,
+} from "spacetimedb";
+
+export default {
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+  effectName: __t.string(),
+  updatedBy: __t.string(),
+};
--- a/frontend/src/lib/spacetime/module_bindings/types.ts
+++ b/frontend/src/lib/spacetime/module_bindings/types.ts
@ -34,6 +34,19 @@ export const Node = __t.object("Node", {
 });
 export type Node = __Infer<typeof Node>;

+export const MixerChannel = __t.object("MixerChannel", {
+  id: __t.string(),
+  roomId: __t.string(),
+  targetUserId: __t.string(),
+  gain: __t.f64(),
+  isMuted: __t.bool(),
+  activeEffects: __t.string(),
+  role: __t.string(),
+  updatedBy: __t.string(),
+  updatedAt: __t.timestamp(),
+});
+export type MixerChannel = __Infer<typeof MixerChannel>;
+
 export const NodeAccess = __t.object("NodeAccess", {
  id: __t.string(),
  subjectId: __t.string(),
--- a/frontend/src/lib/spacetime/module_bindings/types/reducers.ts
+++ b/frontend/src/lib/spacetime/module_bindings/types/reducers.ts
@ -16,6 +16,12 @@ import DeleteNodeAccessForSubjectReducer from "../delete_node_access_for_subject
 import UpdateEdgeReducer from "../update_edge_reducer";
 import UpdateNodeReducer from "../update_node_reducer";
 import UpsertNodeAccessReducer from "../upsert_node_access_reducer";
+import CreateMixerChannelReducer from "../create_mixer_channel_reducer";
+import SetGainReducer from "../set_gain_reducer";
+import SetMuteReducer from "../set_mute_reducer";
+import ToggleEffectReducer from "../toggle_effect_reducer";
+import DeleteMixerChannelReducer from "../delete_mixer_channel_reducer";
+import SetMixerRoleReducer from "../set_mixer_role_reducer";

 export type ClearAllParams = __Infer<typeof ClearAllReducer>;
 export type CreateEdgeParams = __Infer<typeof CreateEdgeReducer>;
@ -27,4 +33,10 @@ export type DeleteNodeAccessForSubjectParams = __Infer<typeof DeleteNodeAccessFo
 export type UpdateEdgeParams = __Infer<typeof UpdateEdgeReducer>;
 export type UpdateNodeParams = __Infer<typeof UpdateNodeReducer>;
 export type UpsertNodeAccessParams = __Infer<typeof UpsertNodeAccessReducer>;
+export type CreateMixerChannelParams = __Infer<typeof CreateMixerChannelReducer>;
+export type SetGainParams = __Infer<typeof SetGainReducer>;
+export type SetMuteParams = __Infer<typeof SetMuteReducer>;
+export type ToggleEffectParams = __Infer<typeof ToggleEffectReducer>;
+export type DeleteMixerChannelParams = __Infer<typeof DeleteMixerChannelReducer>;
+export type SetMixerRoleParams = __Infer<typeof SetMixerRoleReducer>;

--- a/frontend/src/lib/spacetime/stores.svelte.ts
+++ b/frontend/src/lib/spacetime/stores.svelte.ts
@ -13,7 +13,7 @@
 *   const myEdges = $derived(edgeStore.bySource('user-123'));
 */

-import type { Node, Edge, NodeAccess } from './module_bindings/types';
+import type { Node, Edge, NodeAccess, MixerChannel } from './module_bindings/types';
 import type { DbConnection, EventContext } from './module_bindings';

 // ---------------------------------------------------------------------------
@ -271,6 +271,85 @@ function createNodeAccessStore() {

 export const nodeAccessStore = createNodeAccessStore();

+// ---------------------------------------------------------------------------
+// MixerChannel store
+// ---------------------------------------------------------------------------
+
+let _mixerChannels = $state<Map<string, MixerChannel>>(new Map());
+let _mixerVersion = $state(0);
+
+// Secondary index: room_id → set of mixer channel ids
+let _mixerByRoom = $state<Map<string, Set<string>>>(new Map());
+
+function createMixerChannelStore() {
+	return {
+		/** All mixer channels as an array. */
+		get all(): MixerChannel[] {
+			void _mixerVersion;
+			return [..._mixerChannels.values()];
+		},
+
+		/** Get a mixer channel by id ("{room_id}:{target_user_id}"). */
+		get(id: string): MixerChannel | undefined {
+			void _mixerVersion;
+			return _mixerChannels.get(id);
+		},
+
+		/** Get all mixer channels for a room. */
+		byRoom(roomId: string): MixerChannel[] {
+			void _mixerVersion;
+			const ids = _mixerByRoom.get(roomId);
+			if (!ids) return [];
+			return [...ids].map((id) => _mixerChannels.get(id)!).filter(Boolean);
+		},
+
+		/** Get a specific channel for a user in a room. */
+		byParticipant(roomId: string, userId: string): MixerChannel | undefined {
+			void _mixerVersion;
+			return _mixerChannels.get(`${roomId}:${userId}`);
+		},
+
+		/** Number of mixer channels. */
+		get count(): number {
+			void _mixerVersion;
+			return _mixerChannels.size;
+		},
+
+		// -- Internal callbacks for SpacetimeDB --
+		_onInsert(_ctx: EventContext, row: MixerChannel) {
+			_mixerChannels.set(row.id, row);
+			let set = _mixerByRoom.get(row.roomId);
+			if (!set) {
+				set = new Set();
+				_mixerByRoom.set(row.roomId, set);
+			}
+			set.add(row.id);
+			_mixerVersion++;
+		},
+		_onDelete(_ctx: EventContext, row: MixerChannel) {
+			_mixerChannels.delete(row.id);
+			const set = _mixerByRoom.get(row.roomId);
+			if (set) {
+				set.delete(row.id);
+				if (set.size === 0) _mixerByRoom.delete(row.roomId);
+			}
+			_mixerVersion++;
+		},
+		_onUpdate(_ctx: EventContext, oldRow: MixerChannel, newRow: MixerChannel) {
+			_mixerChannels.set(newRow.id, newRow);
+			// room_id doesn't change (part of composite key), so no index update needed
+			_mixerVersion++;
+		},
+		_clear() {
+			_mixerChannels = new Map();
+			_mixerByRoom = new Map();
+			_mixerVersion++;
+		},
+	};
+}
+
+export const mixerChannelStore = createMixerChannelStore();
+
 // ---------------------------------------------------------------------------
 // Visibility filter
 // ---------------------------------------------------------------------------
@ -332,6 +411,7 @@ export function bindStores(conn: DbConnection) {
 	nodeStore._clear();
 	edgeStore._clear();
 	nodeAccessStore._clear();
+	mixerChannelStore._clear();

 	// Register callbacks
 	conn.db.node.onInsert(nodeStore._onInsert);
@ -345,4 +425,8 @@ export function bindStores(conn: DbConnection) {
 	conn.db.node_access.onInsert(nodeAccessStore._onInsert);
 	conn.db.node_access.onDelete(nodeAccessStore._onDelete);
 	conn.db.node_access.onUpdate(nodeAccessStore._onUpdate);
+
+	conn.db.mixer_channel.onInsert(mixerChannelStore._onInsert);
+	conn.db.mixer_channel.onDelete(mixerChannelStore._onDelete);
+	conn.db.mixer_channel.onUpdate(mixerChannelStore._onUpdate);
 }
--- a/spacetimedb/src/lib.rs
+++ b/spacetimedb/src/lib.rs
@ -273,6 +273,30 @@ pub fn delete_edge(ctx: &ReducerContext, id: String) -> Result<(), String> {
    Ok(())
 }

+// =============================================================================
+// Mixer-kanaler (delt mixer-kontroll via SpacetimeDB)
+// =============================================================================
+
+/// Delt mixer-state per kanal i et live-rom.
+/// Transient — finnes bare mens rommet er aktivt.
+/// Alle deltakere abonnerer og ser endringer i sanntid.
+#[spacetimedb::table(accessor = mixer_channel, public)]
+pub struct MixerChannel {
+    #[primary_key]
+    pub id: String, // "{room_id}:{target_user_id}"
+
+    #[index(btree)]
+    pub room_id: String,
+    #[index(btree)]
+    pub target_user_id: String,
+    pub gain: f64, // 0.0–1.5
+    pub is_muted: bool,
+    pub active_effects: String, // JSON: {"fat_bottom": true, "robot": false, ...}
+    pub role: String,           // "editor" | "viewer" — tilgangskontroll
+    pub updated_by: String,
+    pub updated_at: Timestamp,
+}
+
 // =============================================================================
 // Live-rom (sanntidslyd via LiveKit)
 // =============================================================================
@ -403,6 +427,12 @@ pub fn close_live_room(
        ctx.db.room_participant().id().delete(&p.id);
    }

+    // Fjern alle mixer-kanaler for dette rommet
+    let mixer_channels: Vec<_> = ctx.db.mixer_channel().room_id().filter(&room_id).collect();
+    for mc in mixer_channels {
+        ctx.db.mixer_channel().id().delete(&mc.id);
+    }
+
    // Marker rommet som inaktivt
    if let Some(room) = ctx.db.live_room().room_id().find(&room_id) {
        ctx.db.live_room().room_id().update(LiveRoom {
@ -414,11 +444,194 @@ pub fn close_live_room(
    Ok(())
 }

+// =============================================================================
+// Mixer-kontroll reducers
+// =============================================================================
+
+/// Opprett eller oppdater en mixer-kanal med standardverdier.
+#[reducer]
+pub fn create_mixer_channel(
+    ctx: &ReducerContext,
+    room_id: String,
+    target_user_id: String,
+    updated_by: String,
+) -> Result<(), String> {
+    let id = format!("{room_id}:{target_user_id}");
+
+    // Idempotent — oppdater hvis allerede finnes
+    if let Some(existing) = ctx.db.mixer_channel().id().find(&id) {
+        ctx.db.mixer_channel().id().update(MixerChannel {
+            updated_by,
+            updated_at: ctx.timestamp,
+            ..existing
+        });
+        return Ok(());
+    }
+
+    ctx.db.mixer_channel().insert(MixerChannel {
+        id,
+        room_id,
+        target_user_id,
+        gain: 1.0,
+        is_muted: false,
+        active_effects: "{}".to_string(),
+        role: "editor".to_string(),
+        updated_by,
+        updated_at: ctx.timestamp,
+    });
+    Ok(())
+}
+
+/// Sett gain (volum) for en mixer-kanal. Clampes til 0.0–1.5.
+#[reducer]
+pub fn set_gain(
+    ctx: &ReducerContext,
+    room_id: String,
+    target_user_id: String,
+    gain: f64,
+    updated_by: String,
+) -> Result<(), String> {
+    let id = format!("{room_id}:{target_user_id}");
+    let clamped = gain.clamp(0.0, 1.5);
+
+    let existing = ctx.db.mixer_channel().id().find(&id)
+        .ok_or_else(|| format!("Mixer-kanal {} ikke funnet", id))?;
+
+    // Tilgangskontroll: viewer kan ikke endre
+    if existing.role == "viewer" && existing.target_user_id != updated_by {
+        return Err("Viewer kan ikke endre mixer-innstillinger".into());
+    }
+
+    ctx.db.mixer_channel().id().update(MixerChannel {
+        gain: clamped,
+        updated_by,
+        updated_at: ctx.timestamp,
+        ..existing
+    });
+    Ok(())
+}
+
+/// Sett mute-status for en mixer-kanal.
+#[reducer]
+pub fn set_mute(
+    ctx: &ReducerContext,
+    room_id: String,
+    target_user_id: String,
+    is_muted: bool,
+    updated_by: String,
+) -> Result<(), String> {
+    let id = format!("{room_id}:{target_user_id}");
+
+    let existing = ctx.db.mixer_channel().id().find(&id)
+        .ok_or_else(|| format!("Mixer-kanal {} ikke funnet", id))?;
+
+    if existing.role == "viewer" && existing.target_user_id != updated_by {
+        return Err("Viewer kan ikke endre mixer-innstillinger".into());
+    }
+
+    ctx.db.mixer_channel().id().update(MixerChannel {
+        is_muted,
+        updated_by,
+        updated_at: ctx.timestamp,
+        ..existing
+    });
+    Ok(())
+}
+
+/// Toggle en effekt for en mixer-kanal. Effektnavnet slås av/på i active_effects JSON.
+#[reducer]
+pub fn toggle_effect(
+    ctx: &ReducerContext,
+    room_id: String,
+    target_user_id: String,
+    effect_name: String,
+    updated_by: String,
+) -> Result<(), String> {
+    let id = format!("{room_id}:{target_user_id}");
+
+    let existing = ctx.db.mixer_channel().id().find(&id)
+        .ok_or_else(|| format!("Mixer-kanal {} ikke funnet", id))?;
+
+    if existing.role == "viewer" && existing.target_user_id != updated_by {
+        return Err("Viewer kan ikke endre mixer-innstillinger".into());
+    }
+
+    // Parse, toggle, serialize tilbake
+    // Enkel JSON-håndtering uten serde (STDB-moduler er lette)
+    let mut effects = existing.active_effects.clone();
+    if effects.contains(&format!("\"{}\":true", effect_name)) {
+        effects = effects.replace(
+            &format!("\"{}\":true", effect_name),
+            &format!("\"{}\":false", effect_name),
+        );
+    } else if effects.contains(&format!("\"{}\":false", effect_name)) {
+        effects = effects.replace(
+            &format!("\"{}\":false", effect_name),
+            &format!("\"{}\":true", effect_name),
+        );
+    } else {
+        // Effekten finnes ikke — legg til som aktiv
+        if effects == "{}" {
+            effects = format!("{{\"{}\":true}}", effect_name);
+        } else {
+            // Sett inn før siste }
+            effects = effects.trim_end_matches('}').to_string()
+                + &format!(",\"{}\":true}}", effect_name);
+        }
+    }
+
+    ctx.db.mixer_channel().id().update(MixerChannel {
+        active_effects: effects,
+        updated_by,
+        updated_at: ctx.timestamp,
+        ..existing
+    });
+    Ok(())
+}
+
+/// Slett en mixer-kanal (når deltaker forlater rommet).
+#[reducer]
+pub fn delete_mixer_channel(
+    ctx: &ReducerContext,
+    room_id: String,
+    target_user_id: String,
+) -> Result<(), String> {
+    let id = format!("{room_id}:{target_user_id}");
+    ctx.db.mixer_channel().id().delete(&id);
+    Ok(())
+}
+
+/// Sett rolle (editor/viewer) for en mixer-kanal.
+/// Bare eier/admin kan endre rolle.
+#[reducer]
+pub fn set_mixer_role(
+    ctx: &ReducerContext,
+    room_id: String,
+    target_user_id: String,
+    role: String,
+    _updated_by: String,
+) -> Result<(), String> {
+    if role != "editor" && role != "viewer" {
+        return Err(format!("Ugyldig rolle: {}. Bruk 'editor' eller 'viewer'", role));
+    }
+
+    let id = format!("{room_id}:{target_user_id}");
+    let existing = ctx.db.mixer_channel().id().find(&id)
+        .ok_or_else(|| format!("Mixer-kanal {} ikke funnet", id))?;
+
+    ctx.db.mixer_channel().id().update(MixerChannel {
+        role,
+        updated_at: ctx.timestamp,
+        ..existing
+    });
+    Ok(())
+}
+
 // =============================================================================
 // Warmup/vedlikehold
 // =============================================================================

-/// Tøm alle noder, edges og node_access (brukes ved restart/warmup for å unngå duplikater)
+/// Tøm alle noder, edges, node_access og transiente data (brukes ved restart/warmup)
 #[reducer]
 pub fn clear_all(ctx: &ReducerContext) -> Result<(), String> {
    let all_access: Vec<_> = ctx.db.node_access().iter().collect();
@ -433,6 +646,11 @@ pub fn clear_all(ctx: &ReducerContext) -> Result<(), String> {
    for n in all_nodes {
        ctx.db.node().id().delete(&n.id);
    }
-    log::info!("Alle noder, edges og node_access slettet (clear_all)");
+    // Rydd opp transiente data
+    let all_mixer: Vec<_> = ctx.db.mixer_channel().iter().collect();
+    for m in all_mixer {
+        ctx.db.mixer_channel().id().delete(&m.id);
+    }
+    log::info!("Alle noder, edges, node_access og mixer_channels slettet (clear_all)");
    Ok(())
 }
--- a/tasks.md
+++ b/tasks.md
@ -180,8 +180,7 @@ Ref: `docs/features/lydmixer.md`
 - [x] 16.1 LiveKit-klient i frontend: installer `livekit-client`, koble til rom, vis deltakerliste. Deaktiver LiveKit sin auto-attach av `<audio>`-elementer — lyd rutes gjennom Web Audio API i stedet.
 - [x] 16.2 Web Audio mixer-graf: opprett `AudioContext`, `MediaStreamSourceNode` per remote track → per-kanal `GainNode` → master `GainNode` → `destination`. `AnalyserNode` per kanal for VU-meter.
 - [x] 16.3 Mixer-UI (MixerTrait-komponent): kanalstripe per deltaker med volumslider (0–150%), nød-mute-knapp (stor, rød), VU-meter (canvas/CSS), navnelabel. Master-fader og master-mute. Responsivt design (mobil: kompakt fader-modus).
- [~] 16.4 Delt mixer-kontroll via SpacetimeDB: `MixerChannel`-tabell + reducers (`set_gain`, `set_mute`, `toggle_effect`). Frontend abonnerer og oppdaterer Web Audio-graf ved endring fra andre deltakere. Visuell feedback (sliders beveger seg i sanntid). Tilgangskontroll: eier/admin kan sette deltaker til viewer-modus.
-  > Påbegynt: 2026-03-18T04:58
+- [x] 16.4 Delt mixer-kontroll via SpacetimeDB: `MixerChannel`-tabell + reducers (`set_gain`, `set_mute`, `toggle_effect`). Frontend abonnerer og oppdaterer Web Audio-graf ved endring fra andre deltakere. Visuell feedback (sliders beveger seg i sanntid). Tilgangskontroll: eier/admin kan sette deltaker til viewer-modus.
 - [ ] 16.5 Sound pads: pad-grid UI (4×2), forhåndslast lydfiler fra CAS til `AudioBuffer`. Avspilling ved trykk (`AudioBufferSourceNode`). Pad-konfig i `metadata.mixer.pads` (label, farge, cas_hash). Synkronisert avspilling via LiveKit Data Message.
 - [ ] 16.6 EQ-effektkjede: fat bottom (`BiquadFilterNode` lowshelf ~200Hz), sparkle (`BiquadFilterNode` highshelf ~10kHz), exciter (`WaveShaperNode` + highshelf). Per-kanal toggles, synkronisert via STDB. Presets (podcast-stemme, radio-stemme).
 - [ ] 16.7 Stemmeeffekter: robotstemme (ring-modulasjon: `OscillatorNode` → `GainNode.gain`), monsterstemme (egenutviklet `AudioWorkletProcessor` med phase vocoder for pitch shift). Effektvelger-UI per kanal. Parameterjustering (pitch-faktor, oscillator-frekvens).