Windows 7: tv cards

Howdy.

I'm Thinking of buying a TV card for my PC. It is a modern gaming computer and is fairly well speced.

I'm looking at either a Hauppauge WinTV-HVR-2250 TV Tuner Card or a KWorld PC150.

Reading the system requirements they both say that you need a sound card to operate them. My question is why the sound card. Why Is on-board sound not adequate

Thanks

DX elements and even EAX effects for Creative models would be two reasons as well as the higher quailty sound most cards tend to offer. Even while onboard sound chips have been seeing improvements over the last few years the separate expansion cards will still generally have other things available like HD audio as one thought.

Here the tv tuner/capture card wouldn't seem to work out if I was working with the onboard despite the board's 5.1 surround sound capabilities. The tv card's software automatically detects the card and adjusts itself to utilize the output there to the speakers. Without the separate card however the onboard audio chip may not even be detected by a tuner card.