Every time I have looked this up or ask I get a different answer: How do I plug in my third monitor?
I have two samsung syncmasters (DVI/VGA) and a Samsung TV (HDMI/VGA) to connect to an HD 5770 (2 DVI/1HDMI/1Display Port).
Some people say get an active adapter. Some say active only for DVI/DP, but passive HDMI/DP will suffice. Others insist HDMI/DP has to be active. And these adapters are few and far between, going for 100$+ apparently. Really? Might as well throw in a second HD 5770. What? I can't use the DVI's on that one either? Does the HDMI on the GPU only replace a single DVI? I am told the third monitor must be attached to the DP. That or splurge more on one of the few DP compliant monitors out there.
Alright, so an active adapter is really needed if you are going beyond 1200x1920. Generally, not all ports are available at the same time, they are there for flexibility only. IE if the DP port is used, a DVI port is disabled. From what I understand, this card supports only two outputs at the same time which means no three monitor support.
You can also convert display port -> VGA
Edit - looking into this card - its different then which one I thought. Sorry about that! Yes eyefinity requires an active displayport adapter.
Samsung monitor #1 - DVI
Samsung monitor #2 - DisplayPort to DVI using an adapter
Samsung HDTV - HDMI
As for sound... go to AMD's website and download the audio drivers for your card. I heard in some instances that when installing drivers for Radeon cards, the audio drivers are not automatically installed as well.