The M60 goes down to 5 ohms way up at 3,000 Hz so that is not a factor for the amplifier. Other than that it is 6 ohms or more. The 93 db is an in room sensitivity. We are actually in the process of remeasuring the in room sensitivities of all models at this time because we have not done it since the original launch of the Millennia line. We will be posting the in room as well as the anechoic sensitivities shortly. The M60 is 91 db anechoic so my guess would be the in room is probably higher than 93.
President & Chief Engineer