"Very likely that if you feed the speaker from both + outputs (ie. do not
connect the - terminals just each + terminal) you will have the effect
"you want.

More likely smoke if you connect the +s togther. You can only do that to amps that asre designed for it. Some commercial amps are but I know of no consumer amps that are.

The problem is the amps won't share current well and one will be feeding the other. That is very bad because the outputs are passing current but the voltage across them is not dropping.

You can sum the channels with resistors, like 4 ohm at least. But don't cennoct them directly together.

Think also if it is a DC coupled amp and the offset is off say 250 mV and the DC damping factor is 10 @ 8 ohms load, that thing is likely to idle hot. That is on top of all the L-R material working into the emitter resistors which are probably 0.47 ohm.

Amps that you can parallel have special feedback, actually more accurate, so there is alot less imbalnce, both AC and DC. They also do not allow you to connect to or control the channels separately in that mode. Also, they aere built a hell of alot better than most consumer equipment.

I think most Crowns would be OK doing that, but look at what they cost.