Nice Super 7's! I have an old 1978 letter from Speakerlab, that 7's and Superlab 7 owners should find interesting, to wit, the 10' woofer is wired backwards and if you connect your red wire to the terminal with the red mark (conventionally), it will be out of phase with the 12" woofer, so one has to connect the red wire to the black speaker terminal of the 10" speaker and the black wire to the terminal with the red mark. This is true for at least a number of the 10" Speakerlab speakers stamped 7819. I checked mine and found, sure enough, it is true for my 7's. You should check yours with a 9-volt battery though, to confirm.