I've had the 40's for about 2 weeks and they sounded good but I wasn't sure that I wanted to keep them. Last week I ordered a Harman Kardon 3390 80wpc stereo receiver. I had an Onkyo 8255 50 wpc receiver. So I hooked the 40's up to the HK. Holy crap!!!! First off it sounded like I had added a subwoofer. In a good way though. Tight bass. Vocal are crystal clear without being harsh or sibilant. Cds that used to sound kind of wimpy have come to life. It's shocking the difference between these 2 receivers! I always thought that receivers in the same price range sounded pretty much the same. The Onkyo is pretty highly regarded but there is no comparison between the Onkyo and HK receivers. Are Polk speakers and HK receivers considered good synergy? A good match?