Sonarworks Reference 3 for Windows uses Direct Sound drivers. Most sound cards support Direct Sound.
Make sure you have set your hardware to 44.1 kHz sample rate. Otherwise the software will not work.
Yes we support AVID Omni and other AVID sound cards! They work, you only need to change the sample rate to 44.1 kHz. You also need to make sure the AVID sound card is available outside Pro Tools!
If you still encounter problems please submit a request here.