Finally spoke to the tech department. Their number is 800-497-8921 if anyone needs to call. First off, I told them the setup I was running and how the 3805 just didn't seem to effortlessly drive the Polk RTi10's. I then commented that the Polks were reading 4.1 (DCR) on a meter when the dual (bi-ampable) speaker terminals were "jumped," 7.4 on the top; 8 on the bottom when tested individually. Finally-the big question-, was why Denon elected to spec out the 6 ohm rating at 1000Hz instead of full bandwidth and at .7 thd instead of .05. The answer I got didn't surprise me. With a full bandwidth rating, at .05 thd and 6 ohms, the unit will put out approximately 150 watts per channel in stereo mode. My guess was 140. The guy also told me they never recommend driving 4 ohm speakers with any of their units, as they can overheat and shut down. All of their units have filters, or "current limiters" which protect these units incase of hard driving and extended listening at reference levels. I asked the tech if that's the case, why not just disconnect the jumpers and run the top half of the speaker at 7.4, since the bass would be lacking due to the demands on the amp. Many of us have speakers in the 4-5 impedence arena, and it would be foolish to manufacturer a unit that couldn't drive what the industry is marketing. He "remarked it would be more beneficial to set the towers to 'small' and jump the towers - and simply to use extra caution when driving the unit hard." Moral of the story? Don't buy pigs if you can't feed them.