diff --git a/src/features/dsp408/components/ChannelSection/ChannelSection.tsx b/src/features/dsp408/components/ChannelSection/ChannelSection.tsx
index 1ed5ce5..aaada2a 100644
--- a/src/features/dsp408/components/ChannelSection/ChannelSection.tsx
+++ b/src/features/dsp408/components/ChannelSection/ChannelSection.tsx
@@ -36,6 +36,12 @@ import { getPeqCurvePoints, getPeqPhasePoints } from '../../utils/graph/peq';
 import { logSpace, sumCurvePoints, sumPhaseCurvePoints } from '../../utils/graph/curve';
 import { getCrossoverCurvePoints, getCrossoverPhasePoints } from '../../utils/graph/crossover';
 
+function nearestQValue(q: number, values: readonly number[] = PEAK_Q_VALUES): number {
+  return values.reduce((nearest, current) =>
+    Math.abs(current - q) < Math.abs(nearest - q) ? current : nearest
+  );
+}
+
 type GraphView = 'both' | 'magnitude' | 'phase';
 
 function GraphViewToggle({
@@ -133,9 +139,11 @@ function PeqPanelSliders({
   const qDisabled = PEQ_Q_UNUSED.has(peq.filter_type);
   const gainDisabled = !PEQ_GAIN_USED.has(peq.filter_type);
 
+  const nearestQ = nearestQValue(peq.q);
+
   const commit = (overrides: Partial<PEQ>) => {
     const next = { ...peq, ...overrides };
-    return setPEQ(next.gain, next.frequency, next.q, next.filter_type, next.bypass);
+    return setPEQ(next.gain, next.frequency, overrides.q ?? nearestQ, next.filter_type, next.bypass);
   };
 
   return (
@@ -169,9 +177,9 @@ function PeqPanelSliders({
             max={qMax}
             values={PEAK_Q_VALUES}
             formatValue={(v) => v.toFixed(2)}
-            value={peq.q}
+            value={nearestQ}
             onChange={(value) => commit({ q: value })}
-            onInput={(value) => onLiveValue({ ...peq, q: value })}
+            onInput={(value) => onLiveValue({ ...peq, q: nearestQValue(value) })}
             disabled={qDisabled}
             style={{ width: '100%', flex: '1 1 auto' }}
           />
@@ -318,9 +326,16 @@ function PeqBandList({
   bandsOrder: PEQBand[];
 }) {
   const commit = (band: PEQBand, overrides: Partial<PEQ>) => {
-    const peq = liveBands[band] ?? bands[band];
-    const next = { ...peq, ...overrides };
-    return setPEQ(band, next.gain, next.frequency, next.q, next.filter_type, next.bypass);
+    const live = liveBands[band] ?? bands[band];
+    const next = { ...live, ...overrides };
+    return setPEQ(
+      band,
+      next.gain,
+      next.frequency,
+      nearestQValue(next.q),
+      next.filter_type,
+      next.bypass
+    );
   };
 
   return (
@@ -340,6 +355,7 @@ function PeqBandList({
 
         const [qMin, qMax] = PEQ_Q_RANGES[peq.filter_type];
         const qValues = PEAK_Q_VALUES.filter((q) => q >= qMin && q <= qMax);
+        const qValue = nearestQValue(peq.q, qValues.length ? qValues : PEAK_Q_VALUES);
 
         const qDisabled = PEQ_Q_UNUSED.has(peq.filter_type);
         const gainDisabled = !PEQ_GAIN_USED.has(peq.filter_type);
@@ -376,7 +392,7 @@ function PeqBandList({
 
             <ChoiceStepper
               className="peq-band-list__stepper"
-              value={peq.q}
+              value={qValue}
               values={qValues}
               formatLabel={(v) => v.toFixed(2)}
               disabled={qDisabled}
@@ -401,7 +417,14 @@ function PeqBandList({
               formatLabel={(v) =>
                 PEQ_FILTERS_LABEL.find((opt) => opt.value === v)?.label ?? String(v)
               }
-              onChange={(value) => commit(band, { filter_type: value, q: 3.0 })}
+              onChange={(value) => {
+                const [min, max] = PEQ_Q_RANGES[value];
+                const allowed = PEAK_Q_VALUES.filter((q) => q >= min && q <= max);
+                commit(band, {
+                  filter_type: value,
+                  q: nearestQValue(3.0, allowed.length ? allowed : PEAK_Q_VALUES),
+                });
+              }}
             />
 
             <Button
@@ -499,7 +522,7 @@ function ChannelSection({
       // Skip only if already flat — nothing to change.
       if (current.gain === 0 && current.filter_type === PEQFilter.Peak) continue;
 
-      await commitPEQ(band, 0, current.frequency, current.q, PEQFilter.Peak, current.bypass);
+      await commitPEQ(band, 0, current.frequency, nearestQValue(3.0, PEAK_Q_VALUES), PEQFilter.Peak, current.bypass);
     }
 
     setResetting(false);