2420 replacement

[tweeter]

I´ve read that the natural replacement for the 2420 driver is the 2425J one.
What´s the difference between both models and the sound?
Will match the same horns?
Thanks.

[LE15-Thumper]

Well....
The 2420 or it's much sought after consumer version, the LE85, are considered highly collectible by some and yet not others. In my opinion, JBL has definitely advanced in driver design, quality and fidelity.

However, as much as it boggles my mind as to why someone (sane) would pay thousands for a Westrex driver that may have sold new for $50.00, there is an un-doubtable "sex appeal" that these old collectibles have.

Even though the new stuff will "destroy" a lot of the old, there is nothing like holding a 32lb 375 driver in your hand(s) or an LE15A.

Would you rather have a 476Be or a 375 ? I guess for sheer resale value it is a toss up. For raw collectibillity I would take some NOS 375's over the 476Be, for sound the choice is obvious.

What was the question ????

On identical horns it's hard to say which sounds better. Zilch had some nice things to say about the LE85 during one his projects here. I am not sure if that was a quick and dirty 4430, the econowave or what it was.

I have owned both and sold both.....But I sure wish I still had my LE85 / 2420's

[Mike Caldwell]

The 2425 is is couple of generations newer than the 2420. They will directly interchange between horns, the 2425 is drilled and tapped for two bolt horn flanges as well as the standard three bolt JBL flange. The 2420 originally came with an aluminum diaphragm with a tanginal surround pattern. Those original diaphragms very sought after and no longer are available as a new replacement. The 2421 drivers also had an aluminum diaphragm but had the more familiar current diamond surround, those diaphragms are available new but very expensive and hit or miss availability. The 2425 drivers have a titanium diaphragm, diamond surround. The new titanium diaphragms will work in the older 2420, 2421 and their LE driver counter parts. If you are buying some 2420 drivers or LE85 you would want to check what diaphragms are in them if the seals on the back cover screws have been opened. All of the 2420, 2421 and the LE series will be Alnico magnets and the 2425, 2426 drivers are ceramic magnets.

Mike C.

[tweeter]

The 2425 is is couple of generations newer than the 2420. They will directly interchange between horns, the 2425 is drilled and tapped for two bolt horn flanges as well as the standard three bolt JBL flange. The 2420 originally came with an aluminum diaphragm with a tanginal surround pattern. Those original diaphragms very sought after and no longer are available as a new replacement. The 2421 drivers also had an aluminum diaphragm but had the more familiar current diamond surround, those diaphragms are available new but very expensive and hit or miss availability. The 2425 drivers have a titanium diaphragm, diamond surround. The new titanium diaphragms will work in the older 2420, 2421 and their LE driver counter parts. If you are buying some 2420 drivers or LE85 you would want to check what diaphragms are in them if the seals on the back cover screws have been opened. All of the 2420, 2421 and the LE series will be Alnico magnets and the 2425, 2426 drivers are ceramic magnets.

Mike C.

Thanks, but.........what about the sound?

[Mike Caldwell]

I have never done a side by side comparison of the two and have not heard a 2420 with an original diaphragm for some time. The 2420 did not sound as if it had as an extended high end but the was smoother as it was getting out there. Sorry for the vague answer!

[tweeter]

And........what is the difference between the 2425 and the 2426?
To me they seems very similar.....

[Mike Caldwell]

The only difference in the 2425 and the 2426 is the horn mounting flange on the front. The 2425 is cast iron and drilled and tapped for both two and three bolt horn mounting flanges. The 2426 front flange is aluminum and drilled and tapped for only three bolt horn flanges. The 2426 front flange will unscrew off of the throat and then you can use the driver with a thread on horn with 1 3/8 threads. Depending on the choice of horns you want to use with the driver you could use the one that mates up the simplest.

Additional info...
After downloading and reading the 2425 and 2426 spec sheets form the JBL Pro site, the 2425 used a silver inductance canceling ring and the 2426 uses copper. I have both 2425 and 2426 intermixed in some of my cabinets and can not tell the difference.

[speakerdave]

Something I've wondered about--If you compare the specs, the magnetic field intensity seems to suggest the ferrites are replacements for the LE175, not the 85.

[toddalin]

Thanks, but.........what about the sound?

The titanium sounds "edgy" to me at the top of its range. In the 4430s it's as if they are trying to do what they weren't really meant to do.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Revised_L200_v4430.jpg

[badman]

The titanium sounds "edgy" to me at the top of its range. In the 4430s it's as if they are trying to do what they weren't really meant to do.
http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Revised_L200_v4430.jpg

I'd agree with that. I haven't tried coating the (pricey) JBL phragms yet, but my testing of coating some selenium diaphragms worked real trick. I just came into a quad of used 2426h so will likely play with diaphragm coating.

[more10]

Why do you want to replace it? Blown diaphragm?

[sparky2]

Hi. I just replaced a 2420 diaphragm with an Eminence replacement Aluminum unit. It sounds beautiful, with no "edge". I personally like a titanium diaphragm, but some think it is too strident, especially women with good high-frequency hearing. For home use they like silk-dome tweeters. Really soft pretty sound. Not for P.A. use. You can make your own decision whether to fully enjoy your high frequencies, or to please the ladies! I am getting off-subject, Ha, Ha!. -sparky2-

[Mike Caldwell]

Hi. I just replaced a 2420 diaphragm with an Eminence replacement Aluminum unit. It sounds beautiful, with no "edge". I personally like a titanium diaphragm, but some think it is too strident, especially women with good high-frequency hearing. For home use they like silk-dome tweeters. Really soft pretty sound. Not for P.A. use. You can make your own decision whether to fully enjoy your high frequencies, or to please the ladies! I am getting off-subject, Ha, Ha!. -sparky2-

Are sure it was an Eminence, I don't think they make any JBL style drop in replacements. Radian does make an aluminum JBL replacement.

[sparky2]

Are sure it was an Eminence, I don't think they make any JBL style drop in replacements. Radian does make an aluminum JBL replacement.

Yes, I ordered the diaphragm online, and the response was that it was coming from Hong Kong. It says Eminence right on the box. It had identical design, mounting, connections, mounting screws, etc. to the original JBL I will check the box and send you the Eminence part number. It really does sound beautiful in a restored 4320, playing in center channel mode from a Denon receiver, 170 W RMS per channel. I have cranked it up to ear-splitting volumes with no distortion. -sparky2-

[Mr. Widget]

Yes, I ordered the diaphragm online, and the response was that it was coming from Hong Kong.Maybe another Eminence?

As in Eminence HK? Or Eminence Asia? Or ?


Widget

[grumpy]

... Eminence Front

[badman]

... Eminence Front

Nicely played sir. We need to get together again soon.

[Aculous]

Yes, I ordered the diaphragm online, and the response was that it was coming from Hong Kong. It says Eminence right on the box. It had identical design, mounting, connections, mounting screws, etc. to the original JBL I will check the box and send you the Eminence part number. It really does sound beautiful in a restored 4320, playing in center channel mode from a Denon receiver, 170 W RMS per channel. I have cranked it up to ear-splitting volumes with no distortion. -sparky2-


You wouldn't have that part # would you?

I am looking at suitable replacements for the 2420, Partsexpress has the 2426J but at $400 each for something that will sound somewhat "tinny" or "bright" out of the box I hesitate to go down that road.

[speakerdave]

You wouldn't have that part # would you . . . .


I'm done here.

[Aculous]

I'm done here.


I found two 2420s but they look pretty rough. I will get some advice from a local JBL servicer...see what they think about possible JBL diaphragms for them.

and by the response I suppose eminence is not a suitable choice. Roger that...moving on.

[Mike Caldwell]

Here's about as close of a replacement diaphragm as you'll find for a 2420. Or at least find easy, fast and affordable and Radian is real speaker company, not a knock off copy import.
Parts Express, $80
http://www.parts-express.com/radian-1225-8-diaphragm-fits-most-jbl-1-8-ohm--294-720

[Aculous]

Here's about as close of a replacement diaphragm as you'll find for a 2420. Or at least find easy, fast and affordable and Radian is real speaker company, not a knock off copy import.
Parts Express, $80
http://www.parts-express.com/radian-1225-8-diaphragm-fits-most-jbl-1-8-ohm--294-720


Awesome, thank you Mike, appreciate it sir.

Did not know they were knock-off JBLs, the quality looked ok but the specs I was skeptical of their performance. Haven't ever used Radian, USSPEAKER has some of their beryllium drivers and diaphragms which I had looked at before but thats about it. I will check them out.

[tjm001]

Here's about as close of a replacement diaphragm as you'll find for a 2420. Or at least find easy, fast and affordable and Radian is real speaker company, not a knock off copy import.
Parts Express, $80
http://www.parts-express.com/radian-1225-8-diaphragm-fits-most-jbl-1-8-ohm--294-720

I am using these in my LE85s and they sound good to me.

Tom

[martin2395]

I am using these in my LE85s and they sound good to me.

Tom

Radian dia's are fine.