Quote Originally Posted by Altec Best View Post
These are the frequency response graphs of the 288's I measured on a 511E horn for my DIY project that I'm building. These graphs are both the 0 degrees on axis measurements.They both have the 23763 diaphragms.While driver #2 has the 8 Khz notch, driver #1 does NOT... It also has a pretty flat response.
Interesting. So what are you saying? The notch is related to the diaphragm? That would be nice . For now my units seem a lot rougher. They're the radial tangerine ones though....

Those are some nice 288-Cs you're having there. Maybe I should get some of those, only if they wern't so expensive.


I was told when I bought them from an attorney handling the estate of an Altec engineer both drivers had a pretty close matched set of diaphragms.One pair received the 23763 and the second pair received the 25884 and that they were rebuilt and never put into use after rebuild.And I have to agree with that statement.
Any preference toward one of the diagrams? Those graphs are shure good reference material. Did you put the mic close to the horn (like 2-6 inches) or at a 1meter (40 inch) ?

Coen