--- mpg321/ao.c~	2007-06-01 09:34:50.000000000 +0200
+++ mpg321/ao.c	2010-05-11 11:27:13.000000000 +0200
@@ -241,7 +241,9 @@
         /* mad gives us little-endian data; we swap it on big-endian targets, to
           big-endian format, because that's what most drivers expect. */
         format.byte_format = AO_FMT_NATIVE; 
-        
+       
+        format.matrix = "L,R";
+
         if(options.opt & MPG321_USE_AU)
         {
             int driver_id = ao_driver_id("au");