madplay vs. mpg123

I ran more tests.  madplay is fine on Mac.

I used both madplay and mpg123 to decompress a file to wav.
The wav sounds the same on both outputs.

It sounds fine from aplay.
It sounds bad (again) from audacity.

It seems that on this machine, different programs/device drivers
yield very different results.

Any ideas what is different between these programs?
(which drivers to they use...  /dev/dsp?  some alsa driver?)
Perhaps there is some ioctl or something that isn't being
done properly for my card on some programs...

         aaron