Can I jumper across amp speaker outs to a 2nd amp's spkr outs?

Bill, backfeeding an amplifier forces it to act as a load rather than a source. Amps are designed to drive current out to low-impedance load, not consume it.

The nature and extent of the destruction will vary depending on amp technology and topology, but speaking in general terms you could see anything from no effect at all to thermal overload, fried output transistors, and power supply damage.

@devinplombier  Thanks for the reply.  It helps somewhat in answering my question.  I realize that there is no cut-and-dried answer.

Bill

@wbs 

There is a cut and dried answer  DON'T DO IT!

Wasn't  @devinplombier  explanation clear enough for you or do have learning difficulties or maybe your brain has turned to mush.

Have a nice day.  

Wasn't  @devinplombier  explanation clear enough for you or do have learning difficulties or maybe your brain has turned to mush.

What a particularly rude comment.  

@jetter 

Well we all know you can't fix stupid 🤪