[Interesting University tweet to try out]

Actually, the vertical polar radiation IS biased upward, for fewer cabinet reflections, less comingling of wavefronts, plus the nodal randomization of that type of lens , to me dissappears into the soundfield, more rea.dily Also in my case the tweeter is open air mount , which works out great.

[K55 vs 1824 ev midrange ANY HELP]

Actually the 1824m EV mid is in many ways in the same genre as the k-55s. Its freq range is quite close, with mediocre detail and fidelity (like the '55s). It is however a "convex drive". which is not the preffered layout. Makes phase plug design a real *****. Also its an 8 ohm unit, so youll have to inversely proportion your x over values accordingly. I believe sensitivity is about 1 db less....It will work in a pinch, after all, there isnt much around these days in a 1 incher that will want to go down to 400cps...dave

[Interesting University tweet to try out]

and...heres the university... 9you guys werent kidding, this is hard to upload...)

[Interesting University tweet to try out]

Here they are....The gold one is the '59 university, the lens with the tapered slot is my "gold standard".

[Interesting University tweet to try out]

Yes, those do look interesting. Ive run assymetric tweeters for years now and i love em. I tried every compression tweeter on the market, practically, and i ended up with a "transylvania tube" mounted to a JBL 2420 with titanium diaphrams. I have a university tweeter from 1959...looks like a diffraction lens.. i will try to j-peg it to the group soon. Give those a whirl and tell us all how they work out.