Just to reaffirm, yes, I bought the 2809 not the 2309, with the 1800BD together. Taxes were extra, over the price I stated of course. There are great deals out there, just have to look, and seems to be a buyers market right now. Bob, you might want to ask Alan or Brent about your Denon 2309 as well, re. 4ohms. Alan has gotten back to me with answers very quickly, I must say (tks Alan). I figured if I couldn't run the M80's, I could go for the M60's instead as they seem to be similar in sound, albeit not quite as powerfull. BTW, Bob, I emailed both Denon Cda and Denon USA about the 4 ohm question, and neither have contacted me (2 wks). I'm guessing that if the 2809 is ok with 4 ohms then your 2309 should be ok too. If you compare the specs, they are similar. the weight of both are nearly identical/with 15 watt diff output. I would ask Alan for his thoughts as well as Denon.
