Originally posted by: YOyoYOhowsDAjello
THX doesn't really mean much.
For computer speakers, some of the more expensive ones have a THX certification on them, but it basically has nothing to do with the kind of standards used for HT equipment, and even those certifications don't really mean much.
There are plenty of good products out there that are not THX certified, and a THX certified set of computer speakers is not necessarily better than a non-THX set of speakers.
For a HT set, having a center channel has a big benefit if there is more than one person watching. If it's just one person, you can sit right in the sweet spot and have the effect of a phantom center from just your front stereo pair.
If you're having more than one person watch something, a center channel physcially located centrally will really help center the sound that are supposed to be coming from the center (duh 😛 )
Even though your room is small, if you're trying to fill the whole space rather than just one listening position, getting some "real" speakers might be a good idea depending on how much you want to put into it.
So I'm going to have to go ahead and say "need more info" before voting, and don't think the choices you listed are what you should be deciding upon 😛
THX isn't what you should be shooting for, it's better quality which is not dependent on the THX badge.
7.1 vs 5.1 isn't a big deal as the front three speakers are really what is going to make the biggest difference.