@@ -1167,7 +1167,7 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)

     for(ch=1; ch<=s->channels; ch++) {

         float gain = s->mul_bias / 4194304.0f;

         if(s->channel_mode == AC3_CHMODE_DUALMONO) {

-            gain *= s->dynamic_range[ch-1];

+            gain *= s->dynamic_range[2-ch];

         } else {

             gain *= s->dynamic_range[0];

         }