Ok, I have two seperate questions. 1) Why is it that a Marshall 4x12 can run at 16 ohms mono, 4 ohms mono, or 8 ohms stereo? I think the speakers are 16 ohms a piece, and that would explain the 4 ohms mono, and 8 ohms stereo part, but where does the 16 ohms mono come into play? Is it a way of running in series, or am i just way off. I guess I just never got it. Also, why don't we see this on Bass Cabs? Couldn't you run a 4 ohm 4x10 at 4 ohm, or 16ohms? Why is a better question, but COULD you do it? 2) The Ampeg 6x10 is a 4 ohm cabinet. If all of the speakers are 32 ohms, it would be 12 ohms, right? If all of the speakers were 16 ohms, it would be 6 ohms, right? If you had some of one, and some of the other, wouldn't you run certian speakers heavier than the others? Yet another thing that always confused me. Any insight into these mysteries of resistance would be wonderful. Thanks.