Mic input gain (was 3x) and per-user receive gain (was 2x) had asymmetric boost ceilings. Raise both, plus the desktop aux input gain (was 3x), to a uniform 4x (400%) on macOS, iOS, and Windows. The master Output volume slider is unchanged (still 1x). No core changes needed: the C ABI only clamps negatives, so the ceilings live entirely in the client UI sliders. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>