diff --git a/static/ambient/index.html b/static/ambient/index.html
index a15cc00..a3757fd 100644
--- a/static/ambient/index.html
+++ b/static/ambient/index.html
@@ -97,6 +97,10 @@
 <script>
 "use strict";
 const $ = id => document.getElementById(id);
+// Telefone: leichter rechnen, damit der Ton nicht ruckelt (Bild in einfacher Auflösung, ~30 Bilder/s,
+// kürzerer Hall, kein Oversampling, keine Körner-Aufnahme im Hauptthread).
+const LITE = /Android|iPhone|iPad|Mobile/i.test(navigator.userAgent);
+const DPR = () => LITE ? 1 : devicePixelRatio;
 const QS = new URLSearchParams(location.search);
 if (QS.get("embed") === "1") document.documentElement.classList.add("embed");
 let BG = [11, 14, 20];     // Hintergrundfarbe, per ?bg=%23101010 überschreibbar
@@ -235,7 +239,7 @@ function buildGraph() {
   // gemeinsamer Summenbus -> Tape-Sättigung -> Kompressor
   g.mix = ctx.createGain();
   g.drive = ctx.createGain(); g.drive.gain.value = 1.5;
-  g.shaper = ctx.createWaveShaper(); g.shaper.curve = satCurve(1.6); g.shaper.oversample = "2x";
+  g.shaper = ctx.createWaveShaper(); g.shaper.curve = satCurve(1.6); g.shaper.oversample = LITE ? "none" : "2x";
   g.makeup = ctx.createGain(); g.makeup.gain.value = .72;
   g.comp = ctx.createDynamicsCompressor();
   g.comp.threshold.value = -18; g.comp.ratio.value = 3; g.comp.attack.value = .05; g.comp.release.value = .4;
@@ -246,7 +250,7 @@ function buildGraph() {
   g.filter.connect(g.dry).connect(g.mix);
 
   // Hall
-  g.conv = ctx.createConvolver(); g.conv.buffer = makeImpulse(ctx, 7, 2.6);
+  g.conv = ctx.createConvolver(); g.conv.buffer = makeImpulse(ctx, LITE ? 3.5 : 7, 2.6);
   g.send = ctx.createGain(); g.send.gain.value = S.verb;
   g.filter.connect(g.send).connect(g.conv);
   g.conv.connect(g.mix);
@@ -294,16 +298,20 @@ function buildGraph() {
   g.noiseBus.connect(g.mix);
   const nSend = ctx.createGain(); nSend.gain.value = .3; g.noiseBus.connect(nSend).connect(g.conv);
 
-  // Granular: Ringpuffer der Stimmen, daraus werden Körner geschnitten
-  S.ring = new Float32Array(ctx.sampleRate * 12); S.wp = 0; S.written = 0;
-  const proc = ctx.createScriptProcessor(4096, 1, 1);
-  proc.onaudioprocess = e => {
-    const inp = e.inputBuffer.getChannelData(0), n = S.ring.length;
-    for (let i = 0; i < inp.length; i++) { S.ring[S.wp] = inp[i]; S.wp = (S.wp + 1) % n; }
-    S.written += inp.length;
-  };
-  const zero = ctx.createGain(); zero.gain.value = 0;
-  g.voiceBus.connect(proc); proc.connect(zero).connect(ctx.destination);
+  // Granular: Ringpuffer der Stimmen, daraus werden Körner geschnitten. Der ScriptProcessor läuft im
+  // Hauptthread und hält bei Last den ganzen Graphen auf – auf Telefonen gibt es daher keine Körner.
+  S.wp = 0; S.written = 0;
+  if (!LITE) {
+    S.ring = new Float32Array(ctx.sampleRate * 12);
+    const proc = ctx.createScriptProcessor(4096, 1, 1);
+    proc.onaudioprocess = e => {
+      const inp = e.inputBuffer.getChannelData(0), n = S.ring.length;
+      for (let i = 0; i < inp.length; i++) { S.ring[S.wp] = inp[i]; S.wp = (S.wp + 1) % n; }
+      S.written += inp.length;
+    };
+    const zero = ctx.createGain(); zero.gain.value = 0;
+    g.voiceBus.connect(proc); proc.connect(zero).connect(ctx.destination);
+  }
   g.grainBus = ctx.createGain(); g.grainBus.connect(g.filter);
 
   g.modeBus = ctx.createGain(); g.modeBus.connect(g.mix);       // Klangwelten (Rauschen, Natur, …)
@@ -464,7 +472,7 @@ function playSwell(buf, t) {
 // Granulare Wolke aus dem eigenen Output
 function snapGrains() {
   const sr = S.ctx.sampleRate;
-  if (S.written < sr * 6) return;
+  if (!S.ring || S.written < sr * 6) return;
   const len = Math.min(S.written, S.ring.length), b = S.ctx.createBuffer(1, len, sr), d = b.getChannelData(0);
   for (let i = 0; i < len; i++) d[i] = S.ring[(S.wp - len + i + S.ring.length) % S.ring.length];
   S.grainBuf = b;
@@ -1189,8 +1197,8 @@ const cv = $("viz"), cx = cv.getContext("2d");
 S.visUntil = performance.now() + 1500;
 function wake() { if (!rafId) rafId = requestAnimationFrame(draw); }
 function resize() {
-  cv.width = Math.round(cv.clientWidth * devicePixelRatio);
-  cv.height = Math.round(cv.clientHeight * devicePixelRatio);
+  cv.width = Math.round(cv.clientWidth * DPR());
+  cv.height = Math.round(cv.clientHeight * DPR());
   wake();
 }
 resize();
@@ -1204,9 +1212,9 @@ function spawnParticles(ev) {
   const keyHue = (S.root % 12) * 30 + 200;
   for (let i = 0; i < count && parts.length < 450; i++) {
     parts.push({
-      x: x + rnd(-40, 40, Math.random) * devicePixelRatio, y: H * rnd(.55, .85, Math.random),
+      x: x + rnd(-40, 40, Math.random) * DPR(), y: H * rnd(.55, .85, Math.random),
       vx: rnd(-.12, .12, Math.random), vy: -rnd(.08, .4, Math.random) * (ev.kind === "bell" ? 1.6 : 1),
-      r: (ev.kind === "bell" ? rnd(4, 9, Math.random) : rnd(10, 30, Math.random)) * devicePixelRatio,
+      r: (ev.kind === "bell" ? rnd(4, 9, Math.random) : rnd(10, 30, Math.random)) * DPR(),
       life: 0, max: ev.kind === "bell" ? rnd(180, 320, Math.random) : Math.min(ev.dur * 40, 700),
       h: keyHue + (ev.kind === "choir" ? 60 : ev.kind === "bell" ? 25 : 0) + rnd(-12, 12, Math.random),
     });
@@ -1235,13 +1243,16 @@ function modeVis(W, H, dpr) {
       if (n(.06 + a * .05)) add({ x: Math.random() * W, y: H * r(.5, .95), vx: r(-.2, .2), vy: -r(.1, .5), r: r(10, 28) * dpr, max: r(300, 600) });
   }
 }
+let lastDraw = 0;
 function draw(ts) {
   rafId = 0;
-  const W = cv.width, H = cv.height, dpr = devicePixelRatio;
+  const W = cv.width, H = cv.height, dpr = DPR();
   // Nichts zeichnen (und nicht neu planen), wenn versteckt, 0 px groß oder die Musik steht
   if (document.hidden || !W || !H || !cv.clientWidth) return;
   if (!S.running && performance.now() > S.visUntil) return;
   rafId = requestAnimationFrame(draw);
+  if (LITE && ts - lastDraw < 32) return;   // Telefone: ~30 Bilder/s reichen
+  lastDraw = ts;
   cx.globalCompositeOperation = "source-over";
   cx.fillStyle = `rgba(${BG[0]},${BG[1]},${BG[2]},.16)`; cx.fillRect(0, 0, W, H);
   if (!S.g) return;
diff --git a/static/js/sw.js b/static/js/sw.js
index 72a343d..9c4576b 100644
--- a/static/js/sw.js
+++ b/static/js/sw.js
@@ -2,7 +2,7 @@
  * diora service worker — caches the app shell for offline use.
  */
 
-const CACHE = 'diora-v78';
+const CACHE = 'diora-v79';
 const SHELL = [
   '/static/css/app.css',
   '/static/js/app.js',