ImixSetBlockSize

The ImixSetBlockSize function sets mixer (not DirectSound) buffer size. If you experience "choppy" sound try to increase this value. If the latensy is too large decrease this value.
bool	ImixSetBlockSize(
  WORD  ms   //  size of buffer in milliseconds (1/1000 of second)
);

Parameters

ms
Size of buffer in milliseconds (1/1000 of second). Can't be less than 25 and greater than half of the DirectSound buffer. ( Actually it can but !Mixer would use the nearest valid value.)

Return Values

If the function succeeds, the return value is true.

If the function fails, the return value is false.

Remarks

Max latensy is <= 2*ms. Average latensy is 1.5*ms.

The return value is always true.