hey what does a home theatre do like alll those speakers that you have to set up? is it just for bass sounds
I think you're asking, "why 5 or 7 speakers and what do they do"? They recreate the theater sound in your home. With speakers on the sides and behind you as well as the front you can get a 3D feel of sound moving around your room. The subwoofer gives you the rumbling bass.
I have Polk surround speakers with powered sub and Yamaha receiver. Awesome setup. Once you watch a movie with a good surround system you will never go back to regular TV. Go for a better system, it is well worth the extra money.
I should also note that the toughest part on any surround is tweaking it to your hearing preferences.