Genuine 2420 diaphragms ?

[takenodisk]

Hi to all,i need someone to confirm me wether it's a genuine 2420 dia or not(see pics).
I have the opportunity to buy5231752318 a pair of 2420 in good condition hoping the dias are genuine not aftermarket one's,thanks for your help.

[grumpy]

I'd collect more experienced opinions, but they appear original to me...
crispness of form lines, aluminum sheen, screws, red/clear 16ohm marking
:dont-know:

[herki the cat]

I'd collect more experienced opinions, but they appear original to me...
crispness of form lines, aluminum sheen, screws, red/clear 16ohm marking
:dont-know:

I agree with grumpy. These certainly look like genuine 2420 diaphragms. They appear to be quite old & without doubt date back prior to the present after-market clones. Check to determine the resonant frequency has not increased due to extensive use which does work-harden the aluminum.

[takenodisk]

Thanks guys for your replies,i've purchased those 2420's yesterday,while at home i opened the second one and this comes up(see pic) and still no idea,diamond pattern? any idea?thanks for your help.5232152322

[grumpy]

-looks- like a 16 ohm 2421 dia.
(if it's aluminum ... Hard to tell on my phone :P )

[takenodisk]

Hi Grumpy,here's a brighter pic maybe that can help better.Another member said maybe a 2421 dia as pic wasn't bright enough.Anyway thanks again for your help.5232652327

[HCSGuy]

It looks like a legit aluminum 2421 diaphragm, which doesn't do you any good. They need to match. I will now let the topic turn to:
1. Which diaphragm type sounds better.
2. Hey, has anyone seen the flaw on every 175 diaphragm from the original die that James Lansing probably made himself, and never fixed?
3. Where you're going to send them to have the magnets recharged.
3. How Western Electric built the best sounding drivers ever, and we've only gone backwards for the last 62yrs.
4. Why you should be using non-magnetic tools to work on these (someone will post a picture).
5. Two words - Parasitic resonance

Go!

[takenodisk]

Thanks hcs,hope you'll be heard.

[HCSGuy]

Well, no one took my bait:)

If I am correct, you now have (2) 2420 drivers, one with a 2420 diaphragm and one with a 2421 diaphragm, right? Do they both sound OK?

[Oldmics]

2. Hey, has anyone seen the flaw on every 175 diaphragm from the original die that James Lansing probably made himself, and never fixed? :eek:


Go!

O.K. I"ll bite- :confused:

Whats the flaw?

Oldmics

[grumpy]

there's a thread here somewhere... the die/press used had a small dink in it
that shows up in the tangential diaphragms (one of the little triangular pyramids
has what appears to be a tiny crater near the top, IIRC).

[JeffW]

Post #4 (http://www.audioheritage.org/vbulletin/showthread.php?29273-Interchangability-of-1-75-quot-diaphragms-Altec-JBL)

[takenodisk]

@hcs that's right,two different dia's,haven't installed them yet as i intend to return them back to seller.