I've been listening to one speaker for some time, then I swap with the other one to get them broke in. They need a lot of break in.

I measured the offset; tweeter to mid at 20 mm. I didn't think it was a big deal and blew it off but it kept bugging me. I wasn't going to be satisifed until I tested an all pass filter in the tweeter circuit to delay the tweeter signal. I put together a 2 stage all pass using a LM4562. The final delay was just over 50usec. OK, I'm convinced. The difference blew my mind.

Here's the graph of the alignment for both speakers. The drivers were connected in phase, the mic was placed between the drivers at a distance of 10 inches (25cm). The all pass was adjusted for the deepest null.

As soon as some mosfets get here it's amp building time.

Nice work Mikeg.  

And good luck with the new mod position over there.

Greg