I might buy these klipsch surround speakers and this polk center speaker but i wanted to know if i could run them with my z5500. Or if i NEED to buy a reciever
you need to buy a receiver yamaha and onkyo would be my recommendations
No. Those computer speakers (although decent) are self-powered. Like many 'systems' the speakers only work with the included amp and you cannot mix/match. If you took the speakers and attached them to a normal receiver - you will damage the receiver. Your other problem: You should NOT mix one brand of center speaker with another brand left/right. The change in sound as they move from speaker to speaker will blow the illusion of surround sound. You want all 3 front speakers to be tone-matched and ideally all 5.
