I saw a forum on here a while ago that explained this perfectly, but now I can't find it. There's was a video on this forum that explained how you could take a speaker cable, cut it, and solder the end to create a dummy cable. Basically it acted as a dead end so that you could trick an 8 ohm cab into a parallel circuit, making it 4 ohms. I recently picked up a 70's Fender Bassman 50 head that only runs in 4 ohms, so I really want to find this video to make sure what I'm talking about is true, before I either blow out my cab or kill this awesome head. Has anyone ever tried this or have any information on it that could be helpful?