AFA lower, it depends on the build date as to whether the 416 goes lower and WRT higher, all 515s I've dealt with go higher than any OEM 416, i.e. has greater 'snap'. For instance, my 515Bs have a ~20 Hz Fs [avg. 4], lower than any 416 and sufficient HF output run wide open to XO to an 802 super tweeter at 5 kHz/2nd order. Doesn't suit my listening preferences, but some have found it acceptable in certain apps.

That said, I don't know how limited a woofer design 'palette' GPA has available, so the differences may be much less than originally, but with them often just relabeling old Altec data shts. rather than publishing current spec measurements there's no way to know for sure until someone pipes up like Pano was forced to do awhile back.

His and one other person's problems I'm aware of WRT restoring old AlNiCo drivers has convinced me to only recommend buying new from GPA and even then the only measured specs I've seen are a number of 515-8G that spec'd at least as good as published and some a little better, so for the rest, Caveat Emptor applies.

GM