Which 660ti are you looking at? Most cards have 1 dvi, 1 hdmi, and 2 minidp outs. You can do one monitor in hdmi and one in dvi if you want. HDMI and DP are the only video outs that also carry sound. There will be no issue with playing sound on one monitor if you use dvi/vga on the other.Speakers in monitors are always terrible anyway. A ~$40 set of speakers is much better than built in speakers. You won't need any kind of adapter, just an hdmi cable and dvi cable, assuming your monitors have those connections.