PDA

View Full Version : Diaphragm options for 2420/LE85



more10
10-30-2010, 12:39 PM
I am the happy new owner of a pair of 2420 and a pair of LE85. I have not opened them yet, but guy I bought them from told me that the diaphragms are titanium. Most probably they are aftermarket. I havn't opened them yet to check.

I have checked Orange County repairs, and they got the D16R2421, http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-252&Category_Code=JBL-Diaphragms. (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-252&Category_Code=JBL-Diaphragms) I am surprised that they are as pricey as the 4" diaphragms.

I also found the D16R2425, titanium. Not an option.

The Radian 1225-16 is an option. These are aluminium alloy. Are these an option?

And of course aftermarket noname brand. Not an option for me?

Will there be beryllium diaphragms from TrueExtent?

Compared to 4" (diaphragm) drivers, how will these sound?

Which one is more sought after the LE85 or the 2420?

richluvsound
10-30-2010, 01:24 PM
Hi Moreten ,

Be due out any day now : Go with Ti and aquaplas.. You can compensate with your amp choice .
I found Al a little too laid for my music ..... lots of guitar !

Congrats on the purchase !

Rich

more10
01-30-2011, 01:38 PM
175 diaphragm (http://www.audioheritage.org/vbulletin/showthread.php?28069-175-diaphram) talks about these drivers.


Yes...and the 2410, 2421 and 2425, 2470(phenolic) diaphragms are all interchangeable. 2410/LE175 has the tangential compliance.

2421 and 2425 have the diamond pattern compliance.

For longest lasting durability in a metal dome, the titanium unit gets the nod. A coat of aquaplas will tame the resonances of the 2 mil dome.

D16R2410 (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-251&Category_Code=l_jbl_dias) 316$ Aluminium.
D16R2421 (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-252&Category_Code=l_jbl_dias) 336$ Aluminium.
D16R2426 (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-253&Category_Code=l_jbl_dias) 176$ Titanium.
D16R2470 (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-259&Category_Code=l_jbl_dias) 284$ Phenolic.
Radian 1225-16 (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-451&Category_Code=Radian-Diaphragms) 126$ Aluminium alloy with mylar surround.

There seems to be no titanium with aquaplas or beryllium diaphragms.

HCSGuy
01-30-2011, 02:07 PM
Beryllium are not out yet - if anyone here has any information they can give their input, but I do not think their release is imminent.

You are correct on the aquaplas, though you may PM Guido or one of the pro servicers on the forum who may be able to furnish the diaphragms and dust them with aquaplas for you.

I have no experience with different diaphragms - my drivers all have the original diaphragms, though I think the threads I've seen on the topic have generally preferred the aluminum diaphragms with tangential surrounds for sound quality in home use - that's the D16R2410. The D16R2421 is aluminum with diamond surround, D16R2426 is Titanium with Diamond surround.

That's my 2 cents...

more10
01-30-2011, 03:16 PM
Thanks HCSGuy!

In Playing with a 2426 (http://www.audioheritage.org/vbulletin/showthread.php?5213-Playing-with-a-2426&highlight=playing+with+a+2426)Guido test different combinations of drivers and diaphragms.

I am a bit surprised that these drivers with the used horn (2307) doesn't reach 20 kHz. Is this a limitation of the drivers or the horn?

Robh3606
01-30-2011, 06:37 PM
I am a bit surprised that these drivers with the used horn (2307) doesn't reach 20 kHz. Is this a limitation of the drivers or the horn?

A little of both. Here's more recent 2307 measurement I did a couple if years back.

Rob:)

Mr. Widget
01-30-2011, 10:31 PM
Compared to 4" (diaphragm) drivers, how will these sound?The 4" diaphragmed drivers sound more relaxed at all SPLs and play loudly with much more grace than the 1.75" models.


Which one is more sought after the LE85 or the 2420?IN general the JBL Consumer models are more popular with collectors and therefore have higher resale value.


A little of both. Here's more recent 2307 measurement I did a couple if years back.Rob, which driver was that? Is that a "dry" curve, or did you have any compensation?


Widget

more10
01-31-2011, 01:24 AM
My plan is to use both 4" and 1.75" diaphragmed drivers in the same system, the 1.75" above 2,5 kHz. Is there a JBL 1.75" diaphragmed driver/horn combination that will acomplish this?

Mr. Widget
01-31-2011, 09:10 AM
My plan is to use both 4" and 1.75" diaphragmed drivers in the same system, the 1.75" above 2,5 kHz. Is there a JBL 1.75" diaphragmed driver/horn combination that will acomplish this?I think there is very little to gain doing this and this sort of design is fraught with numerous potential design problems. Using a proper tweeter above 10K or so is much easier to integrate and will offer a better top end.


Widget

speakerex
02-09-2011, 01:29 PM
My reference material shows: D16R2421 Aluminum $252.00- generally better sound quality, D16R2425 titanium $135.00- higher power handling, D16R2470 $215.00 phenolic- more mid range. We also have D16R2421 $252.00, D16R2410 $199.00. I never heard of a D16R2426. http://www.reconingspeakers.com/products-page/diaphragms/jbl-diaphragms1/


I am the happy new owner of a pair of 2420 and a pair of LE85. I have not opened them yet, but guy I bought them from told me that the diaphragms are titanium. Most probably they are aftermarket. I havn't opened them yet to check.

I have checked Orange County repairs, and they got the D16R2421, http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-252&Category_Code=JBL-Diaphragms. (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-252&Category_Code=JBL-Diaphragms) I am surprised that they are as pricey as the 4" diaphragms.

I also found the D16R2425, titanium. Not an option.

The Radian 1225-16 is an option. These are aluminium alloy. Are these an option?

And of course aftermarket noname brand. Not an option for me?

Will there be beryllium diaphragms from TrueExtent?

Compared to 4" (diaphragm) drivers, how will these sound?

Which one is more sought after the LE85 or the 2420?

Robh3606
02-12-2011, 04:44 AM
Rob, which driver was that? Is that a "dry" curve, or did you have any compensation?

Hello Widget

That is a 2425 with an Aquaplased 2426 Ti diaphram. It was mounted in my 4344 using a 2307 horn with no HF compensation and no crossover in place. That is with the lense removed.

Rob:)