Fellow Outlaws,

The other day, I was using Rhapsody running through optical out to an optical in of my 990. I have 2.1 sound (Polk Monitor series left/right + Polk powered subwoofer). What I've noticed is that the subwoofer doesn't seem to be doing anything when the music is going through the 990 set to the CD option.

I ask because for instance, when I run Netflix through my Xbox 360 and play a Cheers episode, you can hear all the speakers being used to play "Where Everybody Knows Your Name".
And it sounds great. Play the same thing from the Macbook through the optical & it loses a lot of the sound. The sound distinction between the two connections is very obvious, this is not a "golden ear" type of distinction.

Is there an adjustment I can make where I can produce the sound from the macbook pro so it will use all 3 speakers?

Would a DAC help? I've got a Cambridge DAC Magic lying around but don't want to go through the trouble of hooking it up if it will provide no benefit.

Best,
Twitchy