KLIPSCH TWEETERS, WHICH STOCK TWEETERS ARE THE BEST

The original tweeter in all of these are the Klipsh K77, a Klipsch branded EV T-35. They are excellent tweeters. Originally, the diaphragms came with very fine wires attached, kind of like a human hair. They frequency burned out. But replacement diaphragms are available with beryllium/copper leads that will not burn out. 

Replacing the diaphragm will be tricky for the novice, but is doable. Or one of the speaker repair houses can do it. 

A big step up from the EV T-35 is the EV T-350. They are spendy on the used market and may require a bigger hole to be cut in the cabinet.

Bob Crites makes a replacement tweeter that  a drop in and is based on a currently available horn tweeter. They are not to my taste but YMMV.

Mechans, as per my last post, the Electro Voice T35 is exactly the same tweeter. EV are the ones that supplied Klipsh these tweeters through the whole production run. No difference at all, and not particularly expensive either.

I believe that virtually all of the diaphragms out there for sale are the Asian sourced parts. I have installed quite a few in T-35s and I am very happy with the results.

in one way, reliability, they are far superior to the originals. The original leads were super thin, like a human hair. The replacements have thick leads that don't burn out when conducting power. When you pull the old ones, it is inevitably the lead which is toast, not the diaphragm.

Installing them is not that easy, but if you have DIY soldering experience it is quite doable. Let's be honest, the EV tweeters are peaky no matter what diaphragm is in them, which gives them their characteristic sound which I, for one, like. I know, I'm deaf.