Index: src/modules/module-alsa-sink.c
===================================================================
--- src/modules/module-alsa-sink.c	(revision 1430)
+++ src/modules/module-alsa-sink.c	(revision 1432)
@@ -159,7 +159,11 @@
                 memchunk = &u->memchunk;
         }
 
-        assert(memchunk->memblock && memchunk->memblock->data && memchunk->length && memchunk->memblock->length && (memchunk->length % u->frame_size) == 0);
+        assert(memchunk->memblock);
+        assert(memchunk->memblock->data);
+        assert(memchunk->length);
+        assert(memchunk->memblock->length);
+        assert((memchunk->length % u->frame_size) == 0);
 
         if ((frames = snd_pcm_writei(u->pcm_handle, (uint8_t*) memchunk->memblock->data + memchunk->index, memchunk->length / u->frame_size)) < 0) {
             if (frames == -EAGAIN)
@@ -415,6 +419,9 @@
         goto fail;
     }
 
+    /* ALSA might tweak the sample spec, so recalculate the frame size */
+    frame_size = pa_frame_size(&ss);
+
     if (ss.channels != map.channels)
         /* Seems ALSA didn't like the channel number, so let's fix the channel map */
         pa_channel_map_init_auto(&map, ss.channels, PA_CHANNEL_MAP_ALSA);