Quote Originally Posted by GM View Post
Did this to a pair of 511s for the same reason, but had I known about the yet to be offered 511E at the time, would have instead done what Altec did and I much later did to several pairs of 511s, i.e. cut out the welds and stuck some damping material in the gaps since I had no access to Altec's (probably superior) inserts, IOW IME it's their 'ringing' compounded by its other 'ringing' issues that's the problem, not the pathlength division per se.

Of course one still needs CD horn EQ for flattest response over the widest BW.
…I think I still have some of that pipe fitters rubber that maybe Old Guy or bfish recommended way back if anyone dares to do this.