A friend is building a dedicated home theater and audio room (Very nice equipment-Paradigm Signature and Sub Two).
Anyway he is NOT a techie and does not want all of the bells and whistles of a completely wired home. Very basic but at least so he doesn't have to re-wire or add anything in the future, at least he hopes. He is having the walls spray foamed so this will be an issue even with that.
He was thinking he may go ahead and add a wire for a ceiling projector and wire up the speaker runs for 7.1. The equipment is going to be located in a dedicated closet.
Should he use HDMI for the projector and also run CAT 5/6 for it also for future, just in case? I've read that CAT 5/6 can be converted over to basically any type of cabling with a converter box?
I am not an expert, but I am currently building a house with a home theater and a room next to it which will house all the AV equipment.
I am running a conduit from the A/V room to the projector so any future wire can be pulled through. Even though I will have a 7:1 setup, I am wiring for 11.2 as speaker wires will stay the same. This will future proof the media room.
For the rest of the house, I am running 4 CAT6 cables to each TV location.
Flex conduit and AC power to the projector location. If that area will be spray foamed, probably a 2nd conduit for HDMI cable and cat6 (at least 2) cables.
If your friend is interested enough in A/V gear to have a dedicated theater, he should be wiring the whole house for the future. Once that spray foam goes on, adding any wiring is going to be a major hassle - which puts up a big barrier to any future gear. Wire is cheap - put a bunch in while he can.
Spend some time reading similar threads in the Home A/V Distribution forum, and read the "Wiring Your New House 101" paper: