Newly acquired AR-78LS

[ar_pro]

Those are some good observations, Nigel.

Viewed from the perspective of several decades, it seems to me that the continuity of design might not be so much connected to 3-way systems as to 12"-woofered systems, where the lineage would be AR-1, AR-3, AR-3a, AR-LST, and then over the edge to the dual-woofered original AR-9.

I'm personally unconvinced that the dual-dome mid-tweeters of the later years were an improvement on the last iterations of the separate mid & tweeter domed drivers, and since none of the subsequent 3-way systems were really "bookshelf" models, I'd say that the end of that ancient 3-way bookshelf lineage came with the AR-10pi/AR-11 models, themselves having branched from the main trunk at the advent (sorry) of the LST.