Randy,

I agree with your calculations and the conclusion. Here's another long shot for you to take up with Emotiva.

I understand that they use a modular card cage. So the card cage has connectors that mate with the modules. If these connectors aren't made of the "right" material, their contacts can oxidize over time particularly if they have been sitting on a shelf unmated. So if Emotiva builds the cage and inventories it until need it many months later, the contacts may have oxidized. When they oxidize, their electrical resistance increases. The amplifier's output voltage is proportional to the resistance of the load being driven. If the resistance of the load increases too much, the output voltage can be driven to the supply rails and the amp shuts down. The load that the amp is seing consists of the speaker impedance and the parasitic resistance of the contacts.

The same effect can happen if the connectors are not mating with enough contact force. This is a long shot as every manufacturer should be aware of this kind of an effect but I have seen it happen a few times before with home entertainment and industrial gear.