Good afternoon, TBers. I'd like to build a 4x10 extension cab, but I'm having some trouble figuring out impedance. Let's say I've got 4 8 Ohm speakers with an RMS of 100. If I hook them up all in parallel, I end up with a 2 Ohm circuit, right? What's the RMS for the entire group, 400? What happens if I put the speakers in series 2 apiece on parallel lines? Does that give me 8 Ohms? Is there anyway to get a set of 4 speakers to be be either 4 or 8 Ohms based on the design of the circuit? Your help will be greatly appreciated.