I am just wondering but, I had a set of Energy Connisuers C-7's and now I have the Axiom Mt80's.
But, why is it I have to turn up my volume higher now than I did the Energy's to get the same loudness level.
I used to turn to about -20db with the Energy's now I find I have to go to -5db or so with the Axioms.

The M80s are a 4-ohm speaker, so they demand a higher level of current than the C-7s. The Denon you have is definitely capable of driving them, so that shouldn't be a factor. They are rated as slightly more sensitive than the C-7s, so all else being equal, they should sound a touch louder. Did you calibrate your receiver when you had the C-7s, and have you calibrated it sicne you got the M80s?

Troy, as Peter mentioned, the sensitivities of the C-7s and M80s are nearly identical(90dB using 1 watt for the C-7s and 91dB for the M80s). If everything else was kept constant, i.e. the same source material, the same speaker position, exactly the same loudness level(memory can be tricky), the settings(including impedance)on the 3805 should also be the same.