Comment 8 for bug 227067

oh yeah - once jack is running, the output sample rate of the software has to match the configured jack sample rate or it wont connect.

actually (while running jack) the command:

% mpg123 xxx.mp3
gives:
unable to set up output format (the source is 44100Hz, but the capability matrix shows only 48000Hz, S16)

so you have to run

% mpg123 -r 48000 xxx.mp3

which then exhibits the mentioned audio artifacts.

notably though, the alsa capability matrix shows all (from 8000Hz to 48000Hz, s16, u16, u8,s8,ulaw and alaw)

i found the same thing in audacity, unless the project sample rate == the jack rate the whole thing fails miserably: you don't even get to hear your audio sounding cr*p.