WHich is the BEST SOUND MODE for CIV 4?

[BPM]

I have 5.1 speakers run by an Audigy 2 zs gamer.
As far as I know that supports eax2,3 and 4.

But do I want Civ in the EAX 4 mode or is the 5.1 discreet still the best sound option.?

Thanks for the insight.

 

[BPM]

How about some replys. not "listen and choose which you like best."
I'm basicvally asking does civ4 have a special 5.1 dolby digital sound? that woudl make it a better choice over eax4?