I've been debating with a friend whether or not his Classe CAV-75 75x6 amp "doubles" into 4 ohms. He insists that it will do 150x6 unbridged into 4 ohms. Classe doesn't have any 4 ohm spec for this amp, bridged or unbridged. Then he tells me that Classe is above Proceed and on par with Mark Levinson. Thoughts?