I have a 7.1 channel receiver with extra B channels capable of powering an extra set of speakers in another zone. I would like to power yet another set of speakers in another zone from the same receiver (typical "Home Run" install) but I haven't got any channels left to wire in parallel. What do I need to pull this off so I can control all zones from the same receiver?
Chad, You need a speaker switcher available from companies like Niles. These range in price from $30 -hundreds U.S.D.. You cannot wire two speakers safely off the same terminals. A speaker switcher/selector will allow you to run multiples off the same output terminals safely because it will maintain a constant impedence and prevent an uneven voltage drop across each load which is a bad thing for an amp. Speaker outputs from an amplifier are actually "discrete" which means that they are wired completely independently from one another from output to source which the case of solid state is an output transistor. In actuality however, this could be considered a parallel type of wiring since usually a single voltage source will provide a seperate but equal output for all outputs(transistor to speaker).
Thanks Eric. I thought this might be the case. I've seen all sorts of convoluted wiring to do this without a separate amp or speaker selector. Just wanted to confirm this was a bad idea and not safe for my receiver. The only thing I don't like about the speaker selector idea is that you have to manually push the speaker buttons on the box. I think I may opt for a separate amp (heard good things about the Onkyo M-282), and use the remote control functions on my receiver to switch back and for bewteen A,B, and the amp source. This should work eh?