Hi, I am new to h/t and need some help! I have purchesed polk rti-8(fronts) csi-5(center) fxi-3(surrounds) csi-3(s/back) and klipsch sub-10. I also purchesed a H/K AVR-340 rated at 7x55 wpc. I have to turn the speaker levels up all the way or the volume all the way up to get the speakers to "open up". When the speaker levels are turned up and you crank it up it starts to sound harsh. The question I have is do I have the power that is needed to push these speakers properly or would I need to add an exteral amp to the receiver or simply get seperate pre/pro and amp? And is this klipsch sub going to do well with the polks or should I look at something else in the future? Thanks for any input or thoughts you may have!