I know what you're saying; "There are tons of responses concerning impedance. Just read stupid!" Well, I have. And, sorry, I still have questions. Specific to ME anyway. Someone please help me out here. I'll explain what my goal is and please tell me what I'm looking at. I have a head with TWO 1/4" outputs and one of those NEUTRIK SPEAKON connections. (450W into 1 x 4 ohms or 2 x 8 ohms.) I purchased this amp (Behringer) from a studio and was connected to a Peavey 115BX (800W) with ONE 1/4" input. I don't know what the impedance of the cabinet is. This is part of the problem. I'm about to purchase a Carvin V410T 8ohms cabinet. I would like to stack the 410 on top of the 115. Nothing new here of course. The amp manual advices that the TOTAL impedance be 4 ohms. Here's where I'm confused; the 410 cabinet has TWO 1/4" inputs. But, it states that its 8ohms. Am I to understand that I take both 1/4" out of the amp and connect to both 1/4" inputs of the 410? Is so, does that mean that one input of the 410 represents 16 ohm (maybe two speakers connected) and the other also represents 16 ohms, equalling 8 ohms? If I took ONE output from the amp and connected to ONE input of the 410....what would happen and what am I doing? Ok, next. How do I find out what the hell the impedance is on the Peavey 115? The technical information states that the cabinet can come in "either 4 or 8 ohms". Well, which is it? It certainly doesn't state it on anything. Must I open up the cabinet and look at the actual speaker? But, what does THAT really mean. So, I guess what I'm asking is, can I connect the 450w amp with TWO 1/4" outputs to the TWO 1/4" inputs of the 8ohm 410 and THEN connect the Peavey 115 using the NEUTRIK SPEAKON connection? Would the output still be 450w? Brutal. Back in the day, I'd just plug stuff in and see what happened but, I'm TRYING to be a little more intelligent about it. School me please.