subwoofer and ohm question

[Geoffcin]

does ohm matter if im using a powered subwoofer? if my receiver is rated 8 ohms and my powered sub is at 4 ohms, will that over heat my receiver? i just got the yamaha rxv 2400. im asuming it doesnt matter because the sub uses its own amp.
thanks a head of time.

Are you sending a line-level input into the sub, or powering it from your receivers amps? If it's a line level input (RCA jack) then the powered sub's resistance rating is useless information.

[marky]

its the cheesy AR S8HO sub. im not sure if its 4ohms cause it doesnt say on the sub itself. But i found some info online saying its 4ohms or something like that. im thinking about getting the polk psw303 or 404. they recommend connecting using speaker wires to connect from the L and R channels to the input of the sub and then from the sub to the speakers. what kinna connection is that and does it draw power from the receiver? i currently have the AR s20 as fronts and the polk 6005 as the surrounds and center. im planning on getting another center. what do u guys think i should get? is there a way to connect two subs?