Ok, everybody. Here's what I'm thinking. I just sold my old 4Runner. I didn't include the 212 sub cab I had in the back. I am contemplating building a vertical 212 and slapping those bad boys in there. They are each 4 ohms, I would wire them in series. Frequency response is 25-800 Hz, 400w each. The 3" horn tweeter I'm looking at would be 1k-15k. Anyone think that missing frequency gap would be an issue? I suppose I could add a pair of 6's, if necessary. Also, any issues with installing a pair of input/output jacks wired in series to potentially connect this 8 ohm cab with a 4 ohm 810 cab that I already own? Certainly don't want to screw up my SWR 810, or my GK head. I think this idea is sound in theory (key words: I think).