I'm worried that my Yamaha 5740 receiver won't be able to handle the Ascend CBM 170s I'm getting well. Advertisers list it as 100w a channel but the manual I got with it says 85w a channel. The speakers are 200watts. I've never understood this wattage thing, will having less than the speakers are rated for be bad? How does it affect everything? And is my receiver bad and in need of a replacement?