Currently I dont think this is possible with SDI embedded audio...
What exactly are you 'seeing'?
You would have to extract the embedded SDI audio BEFORE it is captured by catalyst, so that you could route it to a dedicated sound mixer. There would be little point processing the sound with the single SDI video input available on the blackmagic card....
I could see the point if you were using multiple Phoenix SDI cards - However, most of the time sound engineers prefer to process sound separately from video and computers
Check out:
http://www.kramerelectronics.com/pro...p?pid=30&sf=80
or
http://www.bal.co.uk/cgi-bin/cp-app....at&ref=BBEMBED
DO let me know if you require any further support or need to test this scenario...
Simon