Keep in mind that you can't pass Dolby TrueHD over optical. You must send it over HDMI. Optical will only get you standard DD.
If possible, send your audio and video out to your HT via HDMI, then go from the HT to your projector (either HDMI or DVI). That's the only way to get Dolby TrueHD, and DTS-MA, to play.
This is assuming your HT can handle HDMI and DTS-MA/DD TrueHD.