Unless ive misunderstood that switch box selects between pair 1 or pair 2. So as its drawn a cross connection doesn't happen because only on of the linked sets of terminals will ever be connected to the amp.
If it was a cross connection it shouldn't work at all, not just cut out after a while.
Appreciate the input ...almost a pun there.
It is unfortunate that I can switch both Pair(1) and Pair(2) into the on position at the same time. Although I don't fully understand resistance, I had a feeling this would be a bad thing to do ... so always ensure both are off before selecting one or the other. Again, I don't fully appreciate the technicalities of cross-connection, but my 'theory' was that having one or the other would effectively be 'straight through' and not a problem (accepting the risk that I may inadvertently select both and blow something!). Wasn't Scotty always warning Kirk about Phase Reversal
It is interesting reading the comments in the linked Amazon listing for the switch, as I note that the negative reviews mention things like "When switching a speaker output on, one channel can occasionally (often) not switch on. Rocking the switch back and forth can then convince it to come on, but that's far from ideal".
Given your comment and the information from
@DPG , I am thinking that, although there is a significant risk having both 'on', the theory is ok, and it is very likely to be poor manufacturing. It is a great shame we allow Chinese manufacturers to sell items with little to no quality control, invariably producing unsustainable waste
And I do appreciate
@DPG advice to reconsider, although I am no 'audiophile', and only had a practical solution in mind. TBH I don't use the projector screen that much, and would rather has less kit (and the middle speaker is by the TV, which would send said audiophile to an early grave).
Really appreciate everyone's time to help explain. Thank you.
Being really cheeky, would you guys know anything about
RF interference?