Huw Davies (@huw) commented about dlls/dsound/sound3d.c:
#include "dsound_private.h"
/* default velocity of sound in the air */ -#define DEFAULT_VELOCITY 340 +#define DEFAULT_VELOCITY 360
I've not yet looked into the MR in any great detail, but this seems unfortunate. Although of course the speed of sound in air is temperature and pressure dependent, the commonly accepted value at 20 celsius and 1 atm is around 340 m/s.