2 soundcards

Making them run

...

Play MP3 Audio

First sound card (for me Terratec Aureon Fun):

 mpg321 --stdout SomeFile.mp3 | aplay -D hw:0,2,0 -c 2 -t raw -r 44100 -f S16_LE

Second sound card (for me Soundblaster Live):

 mpg123 --stdout SomeFile.mp3 | aplay -D hw:1,0,0 -c 2 -t raw -r 44100 -f S16_LE