Just installed Civ4 on a new 20" iMac Core 2 Duo 2.16, and it looks terrific. A question-- which sound setting should I use? I am using the digital optical out to an old Altec Lansing ADA880 4.1 system with a digital coaxial Dolby AC3 input (I use a Toslink to digital coax converter box on the way). Is it possible to get a digital signal from Civ? I know that the Dolby Surround setting is analog, and the speakers show an analog signal when I use the Discrete 4.0 and 5.1 settings. If I can't get a digital signal, which of those 3 settings (Dolby Surround, Discrete 4.0, Discrete 5.1) is best? I have 4 satellites and a subwoofer, so neither of the final two fit exactly. Thanks!