diff --git a/modules/spl-meter/client.js b/modules/spl-meter/client.js
index 59e3765..b865899 100644
--- a/modules/spl-meter/client.js
+++ b/modules/spl-meter/client.js
@@ -210,7 +210,7 @@ function readoutView(root, moduleApi) {
    */
   function fit() {
     const w = root.clientWidth, h = root.clientHeight;
-    const key = `${w}x${h}:${num.textContent.length}:${unit.textContent}`;
+    const key = `${w}x${h}:${num.textContent.length}:${unit.textContent}:${sub.hidden}`;
     if (key === fitKey || w < 2 || h < 2) return;
     fitKey = key;
 
@@ -257,6 +257,7 @@ function readoutView(root, moduleApi) {
       const parts = [`${payload.weighting || '?'} · ${label}`, `ch ${ch.i}`];
       if (ch.clip) parts.push('CLIP');
       if (!payload.calibrated) parts.push('uncalibrated');
+      sub.hidden = s.caption === false;
       sub.textContent = parts.join('  ·  ');
       fit();
     },
@@ -331,18 +332,22 @@ function spectrumView(root, moduleApi, scrolling) {
   }
 
   if (scrolling) {
-    // A title-bar toggle so the axis can be flipped while watching, without
-    // opening the gear. It writes the same setting the gear does, so the two
-    // never disagree — but saveInstanceSettings deliberately does not remount
-    // us, so the new value is held here too and read back by axis().
+    // The axis lives here and nowhere else (rule 11): a tile does not offer
+    // the same action twice. Icon only, tooltip carries the words (rule 9).
+    // saveInstanceSettings deliberately does not remount us, so the new
+    // value is held here as well and read back by axis().
+    const swapIcon = '<svg viewBox="0 0 16 16" width="13" height="13" fill="none" '
+      + 'stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round">'
+      + '<path d="M2 5h9M8.5 2 11.5 5 8.5 8"/><path d="M14 11H5M7.5 8 4.5 11 7.5 14"/></svg>';
+    const describe = () => (axis() === 'x' ? 'Time left to right' : 'Time top to bottom');
     axisBtn = moduleApi.header.addButton({
-      label: '⇆',
-      title: 'Swap axes',
+      icon: swapIcon,
+      title: describe(),
       onClick() {
         axisOverride = axis() === 'x' ? 'y' : 'x';
         moduleApi.saveInstanceSettings({ axis: axisOverride });
         painted = false;         // the picture means nothing in the other orientation
-        axisBtn.title = axis() === 'x' ? 'Time left to right' : 'Time top to bottom';
+        axisBtn.title = describe();
       },
     });
   }
@@ -403,7 +408,8 @@ function spectrumView(root, moduleApi, scrolling) {
       const freqs = folded.freq;
       let values = folded.db;
       const grid = s.gridlines === true;
-      const axisPad = 13;
+      const showLabels = s.labels !== false;
+      const axisPad = showLabels || grid ? 13 : 0;
 
       if (!scrolling) {
         // Damp the bars toward the measurement. Cosmetic: `values` is what
@@ -450,15 +456,17 @@ function spectrumView(root, moduleApi, scrolling) {
           ctx.fillRect(i * bw, plotH - bh, Math.max(1, bw - (bw > 3 ? 1 : 0)), bh);
         }
 
-        ctx.fillStyle = muted; ctx.font = '9px system-ui'; ctx.textAlign = 'center';
-        for (const l of labels) ctx.fillText(hzLabel(l.f), l.pos, h - 3);
+        if (showLabels) {
+          ctx.fillStyle = muted; ctx.font = '9px system-ui'; ctx.textAlign = 'center';
+          for (const l of labels) ctx.fillText(hzLabel(l.f), l.pos, h - 3);
+        }
         return;
       }
 
       // ── spectrogram ──
       const timeX = axis() === 'x';
       const colW = 2;
-      const gutter = grid ? axisPad : 0;
+      const gutter = showLabels ? axisPad : 0;
       // Frequency occupies whichever axis time does not.
       const freqExtent = timeX ? h - gutter : w - gutter;
       const timeExtent = timeX ? w : h;
@@ -489,7 +497,7 @@ function spectrumView(root, moduleApi, scrolling) {
         }
       }
 
-      if (grid) {
+      if (grid || showLabels) {
         const posOf = (f) => {
           const t = Math.log2(f / freqs[0]) / Math.log2(freqs[freqs.length - 1] / freqs[0]);
           return timeX ? freqExtent - t * freqExtent : gutter + t * freqExtent;
@@ -499,7 +507,7 @@ function spectrumView(root, moduleApi, scrolling) {
         if (timeX) ctx.fillRect(0, h - gutter, w, gutter);
         else ctx.fillRect(0, 0, gutter, h);
         ctx.fillStyle = muted; ctx.font = '9px system-ui';
-        ctx.strokeStyle = border; ctx.globalAlpha = 0.35; ctx.beginPath();
+        ctx.strokeStyle = border; ctx.globalAlpha = grid ? 0.35 : 0; ctx.beginPath();
         for (const l of labels) {
           if (timeX) {
             const y = Math.round(l.pos) + 0.5;
@@ -511,7 +519,7 @@ function spectrumView(root, moduleApi, scrolling) {
         }
         ctx.stroke(); ctx.globalAlpha = 1;
         ctx.textAlign = timeX ? 'left' : 'center';
-        for (const l of labels) {
+        for (const l of showLabels ? labels : []) {
           if (timeX) ctx.fillText(hzLabel(l.f), 2, Math.min(h - gutter - 2, l.pos + 3));
           else ctx.fillText(hzLabel(l.f), l.pos, h - 3);
         }
diff --git a/modules/spl-meter/module.json b/modules/spl-meter/module.json
index f35af77..e469e98 100644
--- a/modules/spl-meter/module.json
+++ b/modules/spl-meter/module.json
@@ -1,7 +1,7 @@
 {
   "id": "spl-meter",
   "name": "SPL Meter",
-  "version": "0.2.1",
+  "version": "0.3.0",
   "proddash": ">=1.5.0",
   "description": "Calibrated sound level, Leq and RTA from an audio input on this machine",
   "permissions": [
diff --git a/modules/spl-meter/server.js b/modules/spl-meter/server.js
index 68fed3a..d3609a4 100644
--- a/modules/spl-meter/server.js
+++ b/modules/spl-meter/server.js
@@ -48,10 +48,10 @@ function averagingField() {
   return {
     type: 'select', label: 'Averaging', default: 'fast',
     options: [
-      { value: 'fast', label: 'Fast — 125 ms' },
-      { value: 'slow', label: 'Slow — 1 s' },
-      { value: 'inf', label: 'Inf — since reset' },
-      { value: 'none', label: 'None — no averaging' },
+      { value: 'fast', label: 'Fast · 125 ms' },
+      { value: 'slow', label: 'Slow · 1 s' },
+      { value: 'inf', label: 'Inf · since reset' },
+      { value: 'none', label: 'None' },
     ],
   };
 }
@@ -63,9 +63,6 @@ function averagingField() {
  */
 const BANDING_FIELD = {
   type: 'select', label: 'Banding', default: '3',
-  help: 'Finer bandings need a wide tile to be worth drawing, and below '
-    + 'roughly 200 Hz the window length limits real resolution however fine '
-    + 'this is set.',
   options: [
     { value: '3', label: '1/3 octave' },
     { value: '6', label: '1/6 octave' },
@@ -193,11 +190,12 @@ module.exports = {
             type: 'select', label: 'Show', default: 'level',
             options: [
               { value: 'level', label: 'Level' },
-              { value: 'leq1m', label: 'Leq, last minute' },
-              { value: 'leq10m', label: 'Leq, last 10 minutes' },
-              { value: 'peakC', label: 'Peak, C-weighted' },
+              { value: 'leq1m', label: 'Leq 1 min' },
+              { value: 'leq10m', label: 'Leq 10 min' },
+              { value: 'peakC', label: 'Peak C' },
             ],
           },
+          caption: { type: 'switch', label: 'Caption', default: true },
           warnAt: { type: 'number', label: 'Amber above', group: 'Thresholds', default: 95 },
           alarmAt: { type: 'number', label: 'Red above', group: 'Thresholds', default: 100 },
         },
@@ -222,15 +220,14 @@ module.exports = {
           banding: BANDING_FIELD,
           smoothing: {
             type: 'select', label: 'Smoothing', default: 'medium',
-            help: 'How hard the bars are damped between frames. Cosmetic only — '
-              + 'it changes the animation, never the measurement.',
             options: [
-              { value: 'off', label: 'Off — every frame as measured' },
+              { value: 'off', label: 'Off' },
               { value: 'light', label: 'Light' },
               { value: 'medium', label: 'Medium' },
               { value: 'heavy', label: 'Heavy' },
             ],
           },
+          labels: { type: 'switch', label: 'Labels', default: true },
           gridlines: { type: 'switch', label: 'Gridlines', default: false },
         },
       },
@@ -240,13 +237,7 @@ module.exports = {
         instanceSchema: {
           channel: CHANNEL_FIELD,
           banding: BANDING_FIELD,
-          axis: {
-            type: 'select', label: 'Time runs', default: 'x',
-            options: [
-              { value: 'x', label: 'Left to right' },
-              { value: 'y', label: 'Top to bottom' },
-            ],
-          },
+          labels: { type: 'switch', label: 'Labels', default: true },
           gridlines: { type: 'switch', label: 'Gridlines', default: false },
         },
       },