Dumb lo-fi question.

I have some older amps with the A, B or A+B switching.  The best way to use the speaker options, is to use a set of speakers in two seperate spaces (rooms/areas). They would normally be switched either A or B, depending on which room/area you were in.  The other option of A+B can be used for bi-wiring one set of speakers if that is desired.

If you don’t want to take a chance on cutting your impedance in half and possibly fry the amp or destroy the speakers, get an external speaker selector box with matching impedance so the amp sees an 8 ohm load even with 6 speakers playing. PM me and I can tell you what units I have used for whole house (master bedroom and bathroom, library room, outside, living room) audio using Yamaha or onkyo receivers or go search for matching impedance selector boxes for 4 or 6 pairs of speakers.

organicsound, you mention bi-wiring one set of speakers by using A+B.

I just put in an offer on a set of low end Polk Audio towers with have double connectors on the back and claim to have a separate crossover for the two woofers (that they call subwoofers) while there is another crossover for the two mids and the tweeter. They are 8 ohm speakers.

On such low end speakers and with my old receiver is there any chance that bi-wiring this way would provide any benefit?

I'm assuming that this would not put any additional strain on the receiver?

Bi-wiring is a waste of effort on a receiver of this sort. If you did  bi-wire the speakers, you would only use one speaker output (A or B) and not both. 

Good to know, thanks.