diff --git a/meow_ui_vol.c b/meow_ui_vol.c
index fdcff49..6269bad 100644
--- a/meow_ui_vol.c
+++ b/meow_ui_vol.c
@@ -110,7 +110,7 @@ int meow_ui_vol_step(const char *path, int dir)
  * 与 launcher meow_dac_vol_write / watchdog wd_vol_write 完全同路径（语义同源）。 */
 void meow_ui_vol_dac_write(int pct)
 {
-    int dac = pct * 255 / 100;
+    int dac = 255 - pct * 255 / 100;   /* CS43198 寄存器=衰减量(0=最响 255=静音)，用户 pct 越大越响 → 反转映射 */
     if (dac < 0) dac = 0;
     if (dac > 255) dac = 255;
     char cmd[160];