As has been mentioned earlier in the thread, a cab merger box like the Palmer or the Radial are an easy, albeit expensive solution.Invest a few bucks and buy a Palmer cab merger.
I made a few because the parts are a fraction of the cost.
Electrically no different than a Y cable, or the internal wiring of a multi speaker cab.
I've thought of making both a parallel Y cable and a serial Y cable, but I didn't want to chop up any of my good speaker cables.
Cab Merger Box - (fairly) Easy DIY - v2.0
(Edit: scroll to end for revised version) So I wanted to try some different speaker combinations with my Class 5 before I build speaker cabs for it. Since the Class 5 head only has speaker jacks for one 8 ohm OR one 16 ohm, I figured I'd get one of those Palmer Cab Merger things that I've...
www.marshallforum.com