Echoing the others...you need a good card, and must have a reasonable 5.1 system to author in 5.1. If you only have a stereo system, you can't mix in 5.1 effectively.
Imagine trying to color correct on a monochrome monitor. It's about the same thing.
I can output 5.1 on my onboard sound no problem using a surround system that accepts seperate channel inputs. However I used the DX audio out & it's kindy twitchy at times. :)
> I have an ASUS K8V-X SE motherboard with the soundcard built in. Should I use a separate card instead? Or does it matter?
Yes, it does matter, but does it matter to you? What are you doing with it? If it’s just for home video, the 5.1 on your motherboard with PC speakers is probably good enough. If this is for discerning customers, you might want to invest a few bucks in good audio equipment.
The more generic is, should you trust the sound from your motherboard in the first place. A second but equally important questions is should you trust the speakers that you plug into the sound chip on your motherboard?
The motherboard sound chip is probably biased toward coloring the sound so that your DVD’s sound great. PC speakers are also coloring the sound so that your DVD’s sound great. What you really want is a sound card and speakers that give a flat frequency response so that you are hearing the “real” sound and not “colored” sound.
I thought my SB Audigy 2 Premium card with Soundworks 5.1 surround speakers were fine for mixing 5.1 surround. That was until I ditched them for an M-Audio Firewire-410 with M-Audio Studiophile LX4 5.1 System. It was like night and day. As if someone had taken ear muffs off of my ears. If you can’t afford a good sound card, I would get the M-Audio Revolution 5.1 card over the Soundblaster card (same price) and day of the week.
If you don't want to pay the big bucks for the Firewire 410, there are still a few of the old M-Audio Delta 410 cards out there too. True, it is unbalanced, but hard to beat for $80 or so.