Hi!
5.1 is not a single speaker, its a specification for surround sound that happens to include 6 speakers.
It is important to consider how your room will affect the sound you hear. Give us some room dimensions, and if (like so many of us) the room is open to others, like on a main floor. Furnishings, lay out, all of that matters!
I would also recommend using the Audioholics website as the great resource it is. Any of the articles will provide you a world of knowledge and will help make sure whatever money you do spend, it is not wasted!
