JBL 2402 Diaphragm

[ndmunro]

Opened up some 2402 bullets today for cleaning and general tidy-up. Found the diaphragm looking like the enclosed. I bought drivers second hand and have never heard them but these diaphragms look original. However someone in past has damaged the disc. Just wondered as these are original, should I keep. I assume musically they are toast...but...

 

[ErnieM]

Might not be that bad. Only way to really know is to measure it in comparison to the good one. Frequency and distortion should show if something is off.

 

[EarlK]

Actually, due to the color of the blue rings, I believe those are 2405 diaphragms.

Assume nothing, that small nick might make a difference in the FR measurements some > but don't just toss the diaphragms ( they are quite valuable + virtually irreplaceable ) .

Have someone measure the performance of both drivers after the diaphragms are re-installed.

Hold the "bullet" nose while tightening it's central screw ( or else you'll twist the diaphragm in place > wrinkling it > and truly ruining it ).

Read this thread ( over at LHF ) for lots of good info about that tweeter family.

 

[EarlK]

I believe what you really have is this variant ( but with the alnico motor ) .

 

[ndmunro]

great info thanks

 

[JR_W]

The blue diaphragm is what gave the JBL 077 with the clear phase plug its distinctive blue hue. As Earl mentioned, unobtanium today (and have been for years, at least the blue tinted version). I don't think any of the JBL ring radiator tweeter diaphragms are currently available and the aftermarket versions have not lived up to the originals.

Be very careful with those, hopefully the nick doesn't propagate to a hole and they should last a while at home stereo levels.