Ever since I first saw them at the audiophile store I worked for in the 80's, I've wanted a set of Polk Audio SDA's.

Of course they quit making them before I could ever afford them. Lately I've had the bug again, but this time I want to build myself a set.
I know the SDA concept well. mid drivers in two rows, 7-1/2 inches apart (the width of the average head, ear to ear) with the out side row being fed an inverted version of the other channel, to cancel out any sound from the other speaker in that ear. Imaging is excellent and the sweet spot is almost everywhere.

I wondered if anyone had any thoughts on this idea, and suggestions on driver choices, cabinet construction etc.
Also anyone who has specs on the original SDA drives and I'd be interested.

I know you can buy the original SDA drivers from Polk still (how's that for support!) but I don't want to clone them, just build something using the same method.

Thanks in advance,
Tachyon