I am buying a Denon 3805 and plan on purchasing either M and K 4 ohm or Axiom 4+ ohm speakers. I am uncertain as to the efficiency of the M and Ks but I had to push the Denon 3803 pretty hard to get a large SPL. I am new on this forum and have questions myself but it sure sounds like Axiom’s are much more efficient and that the Denon will do very well. The dealer that I ordered the 3805 from is recommending that receiver with the M and K so it should do even be better with Axioms.
Now, if you read page 13 of the 3803 (page 16 on the 3805) manual very carefully where is says “More on Speaker Impedance” you will see that if you power loads that are LOWER than 4 ohms for prolonged periods of time that you may activate the protection circuit. It is my personal opinion, and no more, that Denon is trying to tell us all something here without getting into hot water with UL. As I understand the UL approval process, manufacturers are not allowed to rate a receiver into 4-ohm loads unless they have a selector switch between 4 and 8 ohms. Of course a quality manufacture won’t want to do that because the effect of the switch is to significantly lower the voltage output to the speaker terminals. The audiophiles that I have studied recommend that even if the receiver has such a switch that you should leave it in the 8-ohm position even when powering 4-ohm loads. So my advice is that if you want M80ti then go ahead and crank it up!
