I just need a decent external soundcard to complete my carpc setup and I have been looking at the Terratec range, and found the phase 26 usb.
This has 6 channel output (5.1) but I will be using it with my Audiocontrol 3XS Crossover, then from there, running to 3 amps for front, rear and sub.

Would this be a good setup if I just connected the four outputs for L+R, F+R from the soundcard to my x-over?
More to the point will I be able to tell my laptop just to use the front and rear outputs and control them all by my master volume?
This will leave the x-over to sort out a non-fading bass channel.

Is there a better soundcard for my needs? I am using Flac, not mp3 so sound quality is important and I need firewire or usb interface.

Thanks!