To have some reserve in volume I set amplifier's
volume regulator higher
than, say, is needed at current moment. As a result I have software level
noticeably below 100%. I suppose such software volume regulating eats
samples resolution (and, at least theoretically, sometimes I have, say,
12-13 bits rather 16).
If you use the hdsp's matrix mixer, it will render the
volume with
higher precision than 16 bits, so play back unattenuated and control the
output level in the matrix mixer.