During product development on Toradex Computer modules, in case there is a need for confirguration of some special audio codec features, especially those which are not accessible through the common wave API, the AC97 Tweak referenced here will come in handy. This tool is available in the Toradex Colibri Software. 

Listed below is a glimpse of the possible features you could configure while using the AC97 Tweak;

1. headphone driver
2. equalizer settings
3. direct access to audio codec registers
4. record gain
5. enable loopback mode to test the audio signal path
6. record and replay a wave file