Help in identify 2405 tweeter

[soulster42]

Hi All ,

This is my first post here and would appreciate if someone can help me identify my tweeters.
i was given a pair of 2405 which one is working and the other is not.
The one that is working is obvious as it has a 2405 stickers on the back and has a smoother surface while the other doesn't have any indication and body texture is rougher.
When I open up both units I saw that the one that is working has a blue diaphragm with guiding pins on the left and right that fits into the holes nicely but the other one does not have any diaphragm and is without the holes for the diaphragm guiding pin.
My question is are they both the same or are they just made differently as I want to replaced the diaphragms and am worrier if they will fit in since one is without the holes for the diaphragm pin.
Thank you very much and would really appreciate any advice.

[gibber]

Welcome to the forum, soulster42 !

What you have is quite a mixed bag of hardware.

The good news: the working 2405 seems complete and original. The blue diaphragm starts to be useful at ca 7kHz.

The bad news: the other 2405 magnet not only misses the fram (orig JBL are not cheap and blue ones very hard to get).
But it also has the front section taken from a 2405H. THe "H" had a ferrite magnet that centered the diaphragm on its perimeter instead of using the two pins the alnico magnet has. Actually, the two parts (magnet & horn) should not fit on top of each other, right?

My advice: Keep the "blue" one and try to get the same again. Difficult, but perhaps easier than finding a blue fram and drilling the holes into the horn for those two centering pins. Non-blue frams start at 3 or 4 kHz already and have not quite as sweet sounding output on the other side of 8.5 kHz (figure is JBL X/O recommendation) than the blue ones have

Hope i could be of help,
Ralph

[soulster42]

Welcome to the forum, soulster42 !

What you have is quite a mixed bag of hardware.

The good news: the working 2405 seems complete and original. The blue diaphragm starts to be useful at ca 7kHz.

The bad news: the other 2405 magnet not only misses the fram (orig JBL are not cheap and blue ones very hard to get).
But it also has the front section taken from a 2405H. THe "H" had a ferrite magnet that centered the diaphragm on its perimeter instead of using the two pins the alnico magnet has. Actually, the two parts (magnet & horn) should not fit on top of each other, right?

My advice: Keep the "blue" one and try to get the same again. Difficult, but perhaps easier than finding a blue fram and drilling the holes into the horn for those two centering pins. Non-blue frams start at 3 or 4 kHz already and have not quite as sweet sounding output on the other side of 8.5 kHz (figure is JBL X/O recommendation) than the blue ones have

Hope i could be of help,
Ralph

Hi Ralph,

Thanks for your answer, that really solved the mystery. So that means I gotta look for another unit of 2405.

Regards,
Mike

[soulster42]

Welcome to the forum, soulster42 !

What you have is quite a mixed bag of hardware.

The good news: the working 2405 seems complete and original. The blue diaphragm starts to be useful at ca 7kHz.

The bad news: the other 2405 magnet not only misses the fram (orig JBL are not cheap and blue ones very hard to get).
But it also has the front section taken from a 2405H. THe "H" had a ferrite magnet that centered the diaphragm on its perimeter instead of using the two pins the alnico magnet has. Actually, the two parts (magnet & horn) should not fit on top of each other, right?

My advice: Keep the "blue" one and try to get the same again. Difficult, but perhaps easier than finding a blue fram and drilling the holes into the horn for those two centering pins. Non-blue frams start at 3 or 4 kHz already and have not quite as sweet sounding output on the other side of 8.5 kHz (figure is JBL X/O recommendation) than the blue ones have

Hope i could be of help,
Ralph

Hi Ralph,

Looking at it again it doesn't seems to resemble a 2405h . The similarities to a 2405 or 077 is much closer.
Appreciate if you can help to identify the photo below.