Parallel / Series Switch for extenstion cabinets

i had a few people ask about this on some guitar forums. They wanted to be able to use their 2x12" cabinet with one amp at 16ohms and another amp (like a fender bassman) at 4 ohms. this is possible with a cabinet having two 8 ohm speakers using a dpdt switch as shown below:



be sure you use a heavy duty switch that can handle the current. it may also be helpful to do this on a new jack plate so this modification can be reversed, if desired.

note that this switch can also be used with a 4x12 cab with 16 ohm speakers, since two 16ohm speakers in parallel are the equivalent impedance of one 8 ohm speakers. simply follow the diagram for the 8 ohm speakers and then wire a speaker in parallel with each speaker on the diagram.