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View Full Version : JBL 4425 Questions : JBL 2416H vs. RAdian 1225-8



notengewirr
10-29-2011, 06:19 AM
Hi,
i'm a german newbie here :) and since last week i own a very nice pair of JBL 4425.
The speakers are in very good condition and the woofers are refoamed and measured (with data sheet) by a german professional:
http://behringer-electric.de/
He didn't recone because of the very good condition of the original Woofers.
My 4425 came from a studio-basement only stored for custom replacing-requirement,so they are like NOS !

Now i read about the replacing Radian 1225-8 drivers with aluminium diaphragm and Mylar surrounding.(cost 99€ + Back Plate)
The original JBL 2416H is titanium dome with diamond surrounding structur...
Ok there is no need for a replace ,but some people said the Radians are more "refined" sounding and have less distortion because of lower mass.

Somebody compared ???
Cheers
notengewirr

Rudy Kleimann
12-15-2011, 06:53 PM
The Radian diaphragms hold the promise of a smoother sound quality with the inherently better resonance-damping qualities of aluminum as compared to Ti, and the Mylar surrounds on the Radian avoids aluminum surrounds' inherent weakness of work-hardening from high-output flexing which led to cracking and diaphragm failure - the reason JBL switched from Al to Ti as a diaphragm material in the '70's.

I just bought a pair of Radian 1225-8 for use in JBL 2426 drivers. I will be using them on 2344A horns, A/B comparing them directly against another pair of 2426 drivers and 2344A horns in my main home system with 2012H 10" mids in a small box atop JBL 4507 cabinets loaded with JBL 2035H or 2226H 15" woofers.

The pair of 2426 drivers with Radian diaphragms were recently tested and tweaked at a fellow LHS member's "lab" with his TEF analyzer system and newly-completed Plane Wave Tube. The Radian diaphragm F.R. sweeps compare very favorably to my best performing factory Ti 8 ohm diaphragm on another JBL 2426 (actually a 2425HS on a threaded adaptor for 2426=2426).

White: JBL Ti D8R2425
Yellow: Radian 1225-8
Magenta: Radian 1225-8
54079

He did a little tweaking on one of the Radian-equipped drivers and got rid of that dip in the 5.5K to 7KHz area, but he hasn't had time to work on the other one yet.

One of my JBL drivers came from ebay with an aftermarket Ti diaphragm (probably chinese Mfg.)
Just to show what "cheap crap" gets you, he swept it on his PWT/TEF setup, and even after tweaking for over an hour, the best FR graph was deplorable!


White: JBL Ti D8R2425 (same as in above graph)
Yellow: Aftermaket Ti (likely Chinese knock-off) Positive marked with 1/4" round red sticker marked +
54080


I need to come up with one more diaphragm for the project, but can't decide if I should get another JBL Ti diaphragm for stereo comparison listening, or another Radian for a L-C-R Home Theater setup, which is the end goal of the project...


I will start a thread on the project and the listening tests when I get the drivers back and start on the project after the New Year.




Hi,
i'm a german newbie here :) and since last week i own a very nice pair of JBL 4425.
The speakers are in very good condition and the woofers are refoamed and measured (with data sheet) by a german professional:
http://behringer-electric.de/
He didn't recone because of the very good condition of the original Woofers.
My 4425 came from a studio-basement only stored for custom replacing-requirement,so they are like NOS !

Now i read about the replacing Radian 1225-8 drivers with aluminium diaphragm and Mylar surrounding.(cost 99€ + Back Plate)
The original JBL 2416H is titanium dome with diamond surrounding structur...
Ok there is no need for a replace ,but some people said the Radians are more "refined" sounding and have less distortion because of lower mass.

Somebody compared ???
Cheers
notengewirr

Robh3606
12-15-2011, 07:44 PM
Well do you want 4425's or something else??

Rob:)

notengewirr
01-05-2012, 08:33 AM
today i received my new Radian 1225/8 and installed them with the 1225-C back cap quickly.:bouncy:

very clean sounding with good transients & resolution :)
i think they are a little bit smoother especially in the lower mid-range. Top end is similar the Ti's.

I noticed there are holes instead of slots in my 2416 phase plugs. I only heard the plugs with slots are cheeper to produce.
Is there a audible difference ?:confused:

The Mylar surrounding looks like a simple plastic disc with eight holes in it.


here are some pics.




54333

54334 54335

Rudy Kleimann
01-05-2012, 09:38 AM
As far as I know, that looks like a 2415 phase plug. I wonder, did the early model 4425's have 2415H drivers in them?

JBL made a 2415H with that phase plug. All 7 of my 2416H drivers have the radial slit phase plugs.

I have only seen pictures or heard about the 2415H phase plug with the holes. I posted the pics (from an ebay auction) here on another thread a few years ago, asking what they were. Some of the veterans here ID'd them as 2415 drivers with 2416H diaphragms installed.

I recently received a NOS JBL D8R2415 diaphragm that appears to have a copper voice coil wire. JBL supersedes to the D8R2416 when ordering diaphragms for a 2415H. D8R2416 diaphragms use aluminum voice coil wire.

JBL also made a 2416H AND a 2416H-1, but I am not certain of the differences. I once heard that the 2416H-1 had ferrofluid, but that is wrong AFAIK. I have never seen ferrofluid in any JBL drivers, including the ones I have that the diaphragms are labelled 2416H-1.

I also own 4 2417H drivers, and it's phase plug has radial slits. However, the dome of the phase plug is not as high as the previous models, and the 2417 diaphragm is built to match- it will not fit on 2416H drivers because the phase plug of the 2416 sits too high.

I once mounted a bad 2425 diaphragm on top of a 2416 and pushed down on the dome to see how close it is to the phase plug, and it is very close (as it should be).

When I mounted the bad 2425 diaphragm to the 2417H and pushed on it, the space between the diaphragm and phase plug was MUCH greater, perhaps 3-4 times as much as on the 2416 (definitely not right).

Those "aftermarket" diaphragms that claim to fit 2415, 2416, and 2417 drivers, are correct only in that they don't hit the phase plug, but that is it. Besides, the 2417 diaphragm is thinner than the 2416 and the surround is different too. I can't imagine an aftermarket diaphragm sounding anywhere near right in a 2417 -but they "fit".

notengewirr
01-05-2012, 10:08 AM
Hi Rudy,

interesting !

Speak (http://www.dict.cc/englisch-deutsch/Speak.html) of (http://www.dict.cc/englisch-deutsch/of.html) the (http://www.dict.cc/englisch-deutsch/the.html) devil (http://www.dict.cc/englisch-deutsch/devil.html) and (http://www.dict.cc/englisch-deutsch/and.html) the (http://www.dict.cc/englisch-deutsch/the.html) devil (http://www.dict.cc/englisch-deutsch/devil.html) shows (http://www.dict.cc/englisch-deutsch/shows.html) up (http://www.dict.cc/englisch-deutsch/up%21.html)!
Do we all have 2415s :crying:


My 4425 are from 1988 and really originally fitted ,nothing was changed.
Only a few weeks ago,my best friend bought another pair of 4425.He screwed open his 4425 with same result.
Phaseplug with holes ,like mine.Exactly the same.His 4425 are stamped 1989.
Both have the same original titanium D8R2416 fitted.I'm not 100% sure but the coils looks like alu.
One of his diaphragms doesn't fit exactly on the driver-plate.There was a little space and he had problems to center the diaphragm exactly.
We noticed this before,because the Horn produced a "farting" sound by playing Bass-Sinus signals.These farting sounds comes out of the Horn-Front.So he covered the little hole on the back site of the diaphragm.The noise has gone.
In two days he will receive his Radians,then i will check his Drivers again...

Edit: The difference between 2415H & 2416H is =The 2415 have a higher DCR (4.5 vs 3.2) and the holes.
Ok, then JBL must have matched the crossovers for these (early 4425) Versions
here is a pic from my crossover:

54337

Rudy Kleimann
01-05-2012, 01:15 PM
Speak of the devil? :crying: Me?


The 4425 was last produced in 2000 and used a 2416H-1 according to JBL service documentation. Perhaps the early production models used a 2416H (before the -1 variant). The 4425 Brochure posted on jblpro.com is copyyrighted 7/93.

That being said, I suppose it is possible that the model progression could be as follows:

2415H: round holes through phase plug, copper coil on diaphragm

2416H: round holes through phase plug, aluminum coil on diaphragm

2416H-1: annular slits into exponential flare phase plug a la 242x drivers, aluminum coil on diaphragm.

This is only my educated guess and not to be construed as fact.:no:

Considering that your 4425's (and your friends'?) are equipped with the round hole phase plug, who knows?:dont-know:


I can't speak for the dates or original diaphragms on my drivers, as all of mine were bought used. But I know all 7 drivers have the phase plug with annular slits. 4 of them came in MR8xx cabinets. JBL Pro Service docs list 2416H-1 used in all MR8xx models and last produced in 1996. The MR800 Brochure is copyright date 5/91.

Thinking about it, I need to clarify that the drivers I saw on ebay a few years ago were listed as 2416H, but as we all know, the driver itself isn't marked -only the diaphragm. in fact, the only way I was sure about the 2417 vs. 2416 drivers was via the diaphragm fit/phase plug clearance test method I used with old diaphragms.

Rudy Kleimann
01-05-2012, 01:21 PM
I recall noticing the different DCR on my 2415 diaphragm compared to 2416. What the actual impedance is over the frequency range is another matter.

You are referring to the tiny vent hole on the diaphragm assembly/cover, correct? I too have wondered about that. I suppose that the LF driver could pressure up the cabinet high enough and long enough at very low frequencies to modulate the HF diaphragm through that vent hole. the 4425 cabinet is tuned to 34HZ.


Hi Rudy,

interesting !

Speak (http://www.dict.cc/englisch-deutsch/Speak.html) of (http://www.dict.cc/englisch-deutsch/of.html) the (http://www.dict.cc/englisch-deutsch/the.html) devil (http://www.dict.cc/englisch-deutsch/devil.html) and (http://www.dict.cc/englisch-deutsch/and.html) the (http://www.dict.cc/englisch-deutsch/the.html) devil (http://www.dict.cc/englisch-deutsch/devil.html) shows (http://www.dict.cc/englisch-deutsch/shows.html) up (http://www.dict.cc/englisch-deutsch/up%21.html)!
Do we all have 2415s :crying:


My 4425 are from 1988 and really originally fitted ,nothing was changed.
Only a few weeks ago,my best friend bought another pair of 4425.He screwed open his 4425 with same result.
Phaseplug with holes ,like mine.Exactly the same.His 4425 are stamped 1989.
Both have the same original titanium D8R2416 fitted.I'm not 100% sure but the coils looks like alu.
One of his diaphragms doesn't fit exactly on the driver-plate.There was a little space and he had problems to center the diaphragm exactly.
We noticed this before,because the Horn produced a "farting" sound by playing Bass-Sinus signals.These farting sounds comes out of the Horn-Front.So he covered the little hole on the back site of the diaphragm.The noise has gone.
In two days he will receive his Radians,then i will check his Drivers again...

Edit: The difference between 2415H & 2416H is =The 2415 have a higher DCR (4.5 vs 3.2) and the holes.
Ok, then JBL must have matched the crossovers for these (early 4425) Versions
here is a pic from my crossover:

54337

notengewirr
01-05-2012, 01:41 PM
Ok, thank you Rudy :thmbsup:,

i think you're right.I measured my original JBL Ti 2416H diaphragm with 3,2 DC. The radian 1225/8 is the same,so the replacement on my 2416H/2415H will be right.It fits perfectly,so i don't worry about.
This weekend i will measure the DC of my friend Driver too.

...now i have to listen my new Radians....:spin: ...the three-dimensionality ...sounds...WOW.....:nutz:

cheers

Andreas

notengewirr
01-06-2012, 06:04 AM
You are referring to the tiny vent hole on the diaphragm assembly/cover, correct?

correct!

i guess the little vent hole prevent a vacuum behind the diaphragms , or perhaps compensate atmospheric pressure...

The Radian diaphragms don't need this hole ,because the Mylar surround is perforated.So the Air can flow behind the diaphragms.

Guido
01-06-2012, 07:52 AM
Those drivers with holes are 2415 drivers. A bit less top end than the later 2416 drivers with slit phase plug.
I saw a lot of 2415 coming out of 4425 cabinets. Seems that they where used by JBL in earlier 4435 models.

I frequently recommend the alumnium replacements from Radian. They really sound smoother than the Ti's. Well someday we will have Beryllium replacements....

Notengewirr, are you satisfied with the refoam ;)

Happy new year to all,
Guido

grumpy
01-06-2012, 09:04 AM
Seems that they where used by JBL in earlier 4435 models

...and by 4435 (early versions of 4430/5 used a 2421A), you mean 4425?

notengewirr
01-06-2012, 09:07 AM
Hi, today i swapped back to my original titanium D8R2416... Hm...with some music (i prefer electronic music) they sound more forward, more "aggressive"( i think it's this unique JBL Professional Sound)
With pop music & voices the Radians are slight better...more HiFi-like...
puh ...critical decision...and i simply can't decide which of them sounds better...

@ Guido

yes! the refoaming (http://behringer-electric.de) is commendable ! Neat Work !

here are pics of my refoamed 2214H


54342 54343

Guido
01-06-2012, 10:47 AM
...and by 4435 (early versions of 4430/5 used a 2421A), you mean 4425?

Ummm... You're right :o:

It's because I always dream of my 4435 :)

Rudy Kleimann
01-06-2012, 11:25 AM
I didn't know the Radian 1225's had holes in the surround! Perhaps it is for equalizing pressure, as you guessed. Makes sense. Would also prevent the woofer and cabinet from modulating the diaphragm like it was doing in your case. That farting sound you heard was probably the diaphragm crashing into the phase plug. Not good...

I haven't actually seen my pair of Radians 1225's yet, as they are with a fellow LHS member who received, installed, and ran F.R. sweeps on them for me (many thanks, B!) I'll have to take a look for myself when they come home.

My LHS friend and I have been discussing the 4" diaphragm ferrite drivers having reliefs cut into the top plate that allow air to travel from one side of the diaphragm to the other. We were a bit puzzled by its' purpose... I joked about it being a tuned port for the rear chamber :D.

Can you post a front, side, and rear view pic of the Radian covers you bought for use on the 2415/16? Does it have a breather hole in it?


correct!

i guess the little vent hole prevent a vacuum behind the diaphragms , or perhaps compensate atmospheric pressure...

The Radian diaphragms don't need this hole ,because the Mylar surround is perforated.So the Air can flow behind the diaphragms.

notengewirr
01-06-2012, 01:18 PM
i will make better pics soon...
here you can see some holes in the Mylar



54352

Rudy Kleimann
01-06-2012, 01:26 PM
I called Radian about the perforated surround, and after putting me on hold for a moment to consult with the owner/designer of the 1225 diaphragm, this is what I was told:

The two reasons for the holes are:

1: to increase the compliance of the rather stiff mylar surround.

2: To relieve pressure under the surround on ferrofluid in applications where ferrofuid is used in the gap.

BTW- He was the same gentleman you have been in contact with at Radian.

Rudy Kleimann
01-06-2012, 01:59 PM
Does the radian cover have a vent hole in it? Does it have a gasket/make a seal?
I forgot to ask the Radian support guy.


i will make better pics soon...
here you can see some holes in the Mylar



54352

Earl K
01-06-2012, 02:22 PM
Hi,


2415H: round holes through phase plug, copper coil on diaphragm


2415
Those drivers with holes are 2415 drivers. A bit less top end than the later 2416 drivers with slit phase plug.
I saw a lot of 2415 coming out of 4425 cabinets. Seems that they where used by JBL in earlier 4435 models.




> FWIW; I find the original combo surprising smooth sounding ( once some passive EQ has been applied to flatten out it's midband response ) .

54353

> I like the original combination quite a lot . They reach up to 12K quite handily .

> I can understand why they were used in the early 4425s.
> The combo sounds much nicer ( than it actually measures ) .
> Too bad JBL dumped this type of phase plug ( it's very coherent sounding IMO ) // in favour of their standard type annular type.

> I was going to toss out a pair mid-summer ( because I thought they were absolute junk that I got cheap ) .
> Then I re-aligned the diaphragms & then conjured up some passive EQ for the driver/horn combo and listened to them on & off for a morning .

> I was very impressed with the resulting character of this driver ( mated to a small Selenium HM17-25 horn ) .
> Not what one usually expects from a JBL Titanium diaphragm working on a magnetic assembly of this size .

> In a nut-shell ; Great Sounding Pink Noise ! .
> Very well behaved transient character across it's entire pass-band // ie; no discernable, ragged, FR areas that sound like they were about to reach "escape velocity" & then hurt someone upon re-entry. :eek:
> Needless to say , they're now back into the project queue ( ie; a front-fill, micro-box ) .

:)

moparfan
01-06-2012, 03:03 PM
Why did you keep the 4425s instead of the other speakers you had?



Those drivers with holes are 2415 drivers. A bit less top end than the later 2416 drivers with slit phase plug.
I saw a lot of 2415 coming out of 4425 cabinets. Seems that they where used by JBL in earlier 4435 models.

I frequently recommend the alumnium replacements from Radian. They really sound smoother than the Ti's. Well someday we will have Beryllium replacements....

Notengewirr, are you satisfied with the refoam ;)

Happy new year to all,
Guido

notengewirr
01-06-2012, 03:04 PM
Does the radian cover have a vent hole in it? Does it have a gasket/make a seal?
I forgot to ask the Radian support guy.


No hole !

5435454355

Guido
01-06-2012, 05:17 PM
Why did you keep the 4425s instead of the other speakers you had?

I don't have any 4425 any longer. Maybe I don't understand the question.:o:

moparfan
01-06-2012, 08:04 PM
I recall that you used to have a modded pair of 4435s. This thread is of interest to me because I have a set of 4425s sitting around holding up my projector. I originally got them to as surround back speakers but one of them needs a new diaphragm, so I'm making due with a 5.1 system right now.


I don't have any 4425 any longer. Maybe I don't understand the question.:o:

notengewirr
01-07-2012, 02:36 AM
I don't have any 4425 any longer. Maybe I don't understand the question.:o:

...look in your signature = 4425's + ....:hmm:

Guido
01-07-2012, 05:26 AM
...look in your signature = 4425's + ....:hmm:

I wasn't here for a long time. Signature corrected.

notengewirr
01-07-2012, 06:35 AM
@ Guido
...Oh,Goodness! ...now i Know who you are ;) Pass DIY Amps, BLS Horn , Everest Clone...da gibt es nicht viele, die eine Everest 2 in solcher Qualität nachbauen...so klein ist die Welt!
und was machen Sie denn jetzt mit den 4435 ?

with the Radians i'm not 100% satisfied, probably i will send them back and return to my original D8R2416 perhaps with aquaplas;)
Gut ,das ich die dann doch nicht bei Ihnen geordert habe ... irgendwie zischeln die Höhen leicht , nicht ganz so klares "klingeln" in den hohen Lagen.

more10
01-08-2012, 03:50 AM
Or you could keep the diaphragms and swap the driver for an alnico, or at least one with radial phase plug.

Mike F
01-12-2012, 02:37 PM
Good read guys, now I`m a little confused. How many versions of the 4425 are there and how do you know which is which? As a new owner of a pair, I`d like to know.
Incidentaly, where would the serial numbers be? I cant find any.

Rudy Kleimann
01-12-2012, 04:45 PM
Good read guys, now I`m a little confused. How many versions of the 4425 are there and how do you know which is which? As a new owner of a pair, I`d like to know.
Incidentaly, where would the serial numbers be? I cant find any.

Not owning a pair, I can't swear to the Serial number location on 4425, but in other JBLs I own and most JBL's I've seen, it is usually an impression stamping into the metal (or plastic) nameplate (aka foilcal) either on the front baffle or the back near the input connections.

Regarding variants, the only thing I am aware of is the early ones seem to be more likely to have the driver with round holes through the phase plug, while later ones have the (better) phase plug with concentric slits.


See: http://www.jblpro.com/pub/recording/4425.pdf for the Data sheet,
and: http://www.jblproservice.com/pdf/Studio Monitor Series/4425LR.pdf for the exploded diagram. This is the only data specifically about this model I could find on the JBL Pro sites.

If your drivers or crossover part numbers are any different, please post your info on this thread. Include pics with your serial number. Also, help everyone out by going to the "Serial number registry" thread (elsewhere on this forum) and post your data there.

Mike F
01-13-2012, 06:14 PM
This is my situation: one of my horns are not working on a newly acquired pair of 4425`s. My search for a replacement diaphragm came up with these three options.
1- OEM D8R2416 @ $300
2- Radian 1225-8 @ 125
3- Aftermarket @ 50

I decided (for the time being) to order two aftermarket units in the interest of getting these speakers up and running asap as they are far too nice to be on static display and that I cannot bare to be without tunes.
So for $100, I`ll be back in business shortly. BTW, this was before I knew of the Radian option.

I chose not to go with OEM because of price and the fear of a major sonic imbalance between a fresh horn and one that can possibly be 20+ years old. It would seem reasonable to assume an old diaphragm would be much more compliant and respond differently than a new one.

Now, in the event I`m not entirely satisfied with the aftermarket units, what are the differences between OEM and Radian units? One can never go wrong with OEM but are the Radians considered to be inferior,equal or superior to OEM?
I would appreciate some guidance!

louped garouv
01-13-2012, 10:04 PM
Really wish the search engine worked better here on the site directly...
in the meantime..

Google has syntax to allow for website specific searches...


Apologies in advance that the links a bit cheeky!
http://bit.ly/xCirO1


Short of it is that some people seem to think they are acceptable
Others will insist on genuine JBL
still others are waiting with baited breath, so to speak,
for even more 'hi performance' Be aftermarkets....

If you can somehow listen to the various materials...
It could prove to be beneficial, is the generalized advice

edgewound
01-14-2012, 09:59 AM
This is my situation: one of my horns are not working on a newly acquired pair of 4425`s. My search for a replacement diaphragm came up with these three options.
1- OEM D8R2416 @ $300
2- Radian 1225-8 @ 125
3- Aftermarket @ 50

I decided (for the time being) to order two aftermarket units in the interest of getting these speakers up and running asap as they are far too nice to be on static display and that I cannot bare to be without tunes.
So for $100, I`ll be back in business shortly. BTW, this was before I knew of the Radian option.

I chose not to go with OEM because of price and the fear of a major sonic imbalance between a fresh horn and one that can possibly be 20+ years old. It would seem reasonable to assume an old diaphragm would be much more compliant and respond differently than a new one.

Now, in the event I`m not entirely satisfied with the aftermarket units, what are the differences between OEM and Radian units? One can never go wrong with OEM but are the Radians considered to be inferior,equal or superior to OEM?
I would appreciate some guidance!

MSRP on D8R2416 is $212.00ea

I might have a couple in stock for a better price if you're interested in the OEM...I'll have to check to see if I have two. Call or message me if you like.

You can check the OEM price list on my website through the link in my signature.

1-888-990-1049

edgewound
01-14-2012, 12:53 PM
MSRP on D8R2416 is $212.00ea

I might have a couple in stock for a better price if you're interested in the OEM...I'll have to check to see if I have two. Call or message me if you like.

You can check the OEM price list on my website through the link in my signature.

1-888-990-1049

Confirmed. I have a pair in stock.

subwoof
01-14-2012, 01:39 PM
post a pic of the bad dia so I can see the exact version - I have some of the older 2416H in the used pile. most of the 4425's I have run across have these, not the later 2416H-1

Get a case of bradour in my pocket and I'll send you one..:)

*cheers*

Mike F
01-14-2012, 06:48 PM
MSRP on D8R2416 is $212.00ea

I might have a couple in stock for a better price if you're interested in the OEM...I'll have to check to see if I have two. Call or message me if you like.

You can check the OEM price list on my website through the link in my signature.

1-888-990-1049

Thank you for the reply and kind offer. PM me a price please. I`m a little worried shipping costs from the West Coast may negate any actual savings.

Mike F
01-14-2012, 06:55 PM
post a pic of the bad dia so I can see the exact version - I have some of the older 2416H in the used pile. most of the 4425's I have run across have these, not the later 2416H-1

Get a case of bradour in my pocket and I'll send you one..:)

*cheers*

Great, yet another variable..:D I`ll take a look, get a shot of it tomorrow. What are the differences?
In the mean time, I`ll get a shipping quote for the Brador.

Mike F
01-14-2012, 08:35 PM
5444154442
post a pic of the bad dia so I can see the exact version - I have some of the older 2416H in the used pile. most of the 4425's I have run across have these, not the later 2416H-1

Get a case of bradour in my pocket and I'll send you one..:)

*cheers*

subwoof
01-15-2012, 05:44 AM
the magnet core you posted is the 2415 - you can tell by the round "salt pepper" holes in the phase plug. To the best of my knowledge that driver was only used in the very early "G" series MI cabinets...

This was superseded by the 2416 which has the annular slits like all the other JBL drivers and is considered an improvement.

And the 2416H-1 driver's diaphram I think is just a tweaked 2416 with better adhesive and the tiny tiny air pressure relief hole in the back.

So now we need you to post *both* of the magnets to see if there is a difference before we strategize further. While your budget is always of concern, you *do* want to treat your left and right ears fairly..:)

sub

Mike F
01-15-2012, 07:29 AM
the magnet core you posted is the 2415 - you can tell by the round "salt pepper" holes in the phase plug. To the best of my knowledge that driver was only used in the very early "G" series MI cabinets...

This was superseded by the 2416 which has the annular slits like all the other JBL drivers and is considered an improvement.

And the 2416H-1 driver's diaphram I think is just a tweaked 2416 with better adhesive and the tiny tiny air pressure relief hole in the back.

So now we need you to post *both* of the magnets to see if there is a difference before we strategize further. While your budget is always of concern, you *do* want to treat your left and right ears fairly..:)

sub
The other driver is identical. So you are saying that this is a 2415?
There is no mention of that model on the Radian website in the list of compatable diaphragms
http://radianaudio.com//index.php?page=shop.product_details&flypage=shop.flypage&product_id=27041&category_id=20&manufacturer_id=0&option=com_virtuemart&Itemid=40

What other JBL models used the 2416? It would appear then that my pair is a later production model, correct? Approximately when did JBL go from the 2416 to the 2415 to get an approximate D.O.B. seing there are no serial numbers anywhere to be found. Sorry for all the questions I`m borderline obsessive compulsive:D

subwoof
01-15-2012, 07:46 AM
the order is 2415H - 2416H - 2416H-1

All have interchangeable parts - it looks like you have the first gen 4425's from 1982 that shared the same drivers as the new MI speaker systems.

Not to fret - simply installing the 2416H diaphram to match the working one will bring these back to 100%. The changes over the next few gens are miniscule and are more related to production methods / expense anyways. These became kickass bookshelve speakers in a hurry and we put a lot of them in DJ booths. And they DID pass the SAF test at home.

PM your ship info soon - I am headed back home after a week's workation but am stopping by the little shop of frozen horrors and will look for a 2416 dia.

sub

subwoof
01-15-2012, 08:46 AM
Many versions / production runs of the 4425 had serial numbers that were just little white stickers stuck onto the input terminal cup - pretty cheap. And nowhere inside the cabinet are ther references to it.

Seems that these were blasted out in high volumes and not stamping the nice aluminum foilcal meant less work...sigh...


BTW the earlier models used the standard 5 way binding posts and the woofer ( 2214H ) had them also.

Later versions used the recessed / angled dual banana posts and the woofer was the 2214H-1 which had the polorized spade connectors.

I have 3 sets of these in various states of use / repair and each is slightly different. Swapping woofers is a PITA with the terminal diff...grrr...

sub

Lee in Montreal
01-15-2012, 08:46 AM
Just adding to the discussion that Radian is one of the very few suppliers of replacement diaphragms for JBl drivers that offers data comparing their product with an original JBL diaphragm. Priced between an original JBL part and a waste-o-money Chinese knock-off, Radian diaphragms make sense for those who don't seek the exact JBL sound. ;)

http://radianaudio.com//components/com_virtuemart/shop_image/prod_files/1245_1225.pdf

Rudy Kleimann
01-15-2012, 10:02 AM
Just adding to the discussion that Radian is one of the very few suppliers of replacement diaphragms for JBl drivers that offers data comparing their product with an original JBL diaphragm. Priced between an original JBL part and a waste-o-money Chinese knock-off, Radian diaphragms make sense for those who don't seek the exact JBL sound. ;)

http://radianaudio.com//components/com_virtuemart/shop_image/prod_files/1245_1225.pdf

I agree with you on the Radians and the cheap chinese knockoffs! See my post re: actual PWT measurements of 2425 driver with Factory-installed JBL diaphragms, Radian dias. and a cheap chinese knockoff:

http://www.audioheritage.org/vbulletin/showthread.php?31988-JBL-4425-Questions-JBL-2416H-vs-RAdian-1225-8&p=325397&highlight=#post325397

Regarding the three variants of JBL drivers and replacement drivers, subwoof has it right. Edgewound and subwoof enlightened me a few years ago (thanks, guys! :wave:) about the "Salt and Pepper shaker" phase plug being from a 2415H driver after I posted pics of pair for sale on ebay asking what they were.

While on the subject, don't be tempted to "upgrade" to the 2417 diaphragm. The 2416 diaphragm is lighter (thinner),has a very tiny diamond pattern stamped into the surround, a different back cap, and about 5 dB more output at 15KHz than previous models (according to the JBL SR Series II catalog).
However, the 2417H phase plug is not as high as the previous models and the 2417 diaphragm will contact the 2415/2416 phase plug before the diaphragm mounting flange seats on the magnet.
The 2415/2416/Radian/aftermarket diaphragms will "fit" the 2417, but I can't imagine them sounding very good due the much greater air space between the diaphragm and the 2417 phase plug.

I proved this while trying to positively identify a 2417 driver I had acquired but, like all of these, has no model number markings on the driver itself. I had a blown 2425 diaphragm (no cover) that I dropped onti the 2417 and pressed down on the diaphragm to check phase plug clearance. It seems to be enormous! got out a 2416H driver and put the 2425 diaphragm on it to check phase plug clearance, and it was close- as it should be. I then took a 2417 diaphragm and gently lowered it onto the 2416 driver until it teetered on the phase plug. That was enough to convince me that I indeed had a 2417 driver and ordered a new JBL diaphragm for it.


Prior to this the only known clue to ID a 2417 was a slightly rounded outer edge to the magnet top plate stamping, but that apparently does not hold true.. I bought one on ebay that was purported to be a 2417, but looked exactly like the 2416's sharply defined top plate edge. I was suspicious. Now I know the only way to positively ID a 2416 or 2417H driver is to fit test a 2417 or an unusable 2425 diaphragm , or measure the phase plug height if you have the means to accurately do so.

Lastly, I recently purchased a NOS JBL 2415H diaphragm, and the major differences I can spot are that the voice coil winding appears to be of copper instead of aluminum, and the DC resistance is much different-4.4 ohms on the 2415 dia and 2.9-3.1 ohms on my 2416 dias.

All of the JBL diaphragm variants I have (2415H, 2416H, and 2416H-1) do have the pin hole vent in the cap. The Radian cover and sealing gasket sold to use with their 1225 dia on 2415/16 drivers does not have a vent hole. However, their surround is perforated, which allows for pressure equalization. The sealed back cap also prevents the woofer from modulating the diaphragm at high level low frequencies.

Read through the sister thread I linked above for more details.

Perhaps a moderator should combine these threads?

Earl K
01-15-2012, 10:27 AM
Good info there Rudy , about the 2417 being a different beast all-together . I didn't know that . Thanks !

I had also wondered whether or not my 2425 diaphragms would properly fit the (2) 2415 magnetic assemblies that I have here / & now I know that they should . :thmbsup:



:)

Rudy Kleimann
01-15-2012, 12:01 PM
Good info there Rudy , about the 2417 being a different beast all-together . I didn't know that . Thanks !I had also wondered whether or not my 2425 diaphragms would properly fit the (2) 2415 magnetic assemblies that I have here / & now I know that they should . :thmbsup::)

Yeah, just order backcap kits from Radian and run the JBL 2425 or Radian 1225 diaphragm in it. I'll be doing that myself shortly.

I've no personal experience with th 2415H "salt shaker phase plug" driver, but I think it is safe to say that the phase plug profile and compatibility is there, considering the JBL 2415 replacement diaphragm supersedes to a 2416H-1 diaphragm. For that matter, I think it is possible that the filter network may not care either, since the impedance curve may not be much different between the 2415 copper coil and the 2416 aluminum coil. It would be interesting to see/compare impedance plots of the two diaphragms and the networks from a very early 4425 and a late-model 4425.

The 2418, used in MR9xx, several EON's, and maybe a couple others, is yet another beast with an entirely different diaphragm and a separate back cap.The diaphragm is so cheesy-looking and flimsy to the touch that I never took it any more seriously than I do a 2412H... I'm not even sure it is titanium, so I never have fooled around with one. My personal feeling about the 2418H is that it is an example of upper management profit motives trumping product design and manufacturing quality.

DavidF
01-16-2012, 10:12 AM
"... Sorry for all the questions I`m borderline obsessive compulsive:D Well, then. We will have to work on getting you over the line. :blink:

subwoof
01-16-2012, 11:39 AM
just brought a 2416H dia from the shop and it *does* have the tiny hole. a sister one did not though..:)

My take on the 2415 magnet being used for an extended time on the early production runs (4425) was to keep the sound consistent until a wholesale change was made ( network and woofer for the A version ) and POSSIBLY for the short-lived consumer variant...

one of these days I will do a swapfest on the odd magnets here - I have everyone mentioned so far in this thread except the 2418 or 2412 MI junkers.

sub

Mike F
01-27-2012, 04:12 PM
OEM
54608
Aftermarket Left
54609
Aftermarket Right
54611
Radian
54610

Did some measurements between the 3 different models, L-Pads set at -2.5 and -1 db, mid and high respectively.
Only after taking the pictures did I realize those measurements were ones taken with the secondary microphone which was placed 21" inches from the horn and at a right angle.
Here is one shot of the Radian. Microphone 18" and on axis to horn.
54612

Notice the differences between the Left and Right aftermarket diaphragms:eek:
While not the most scientific test, it easy to see that the aftermarket diaphragms stink. 10 minutes of listening to them sent me to place an order for the Radians.
I suppose the aftermarket response could be hammered into shape with eq but I figured the 4425s deserve better.
BTW, both left and right Radians measured exactly the same.

1audiohack
01-27-2012, 05:03 PM
I'm glad that worked out for you.

Enjoy!

Mike F
01-27-2012, 08:07 PM
Here are a couple of shots. Chinese on left, JBL on right.
54619

Radian

54620

Hopefully this will help someone in making a more informed decision:)

notengewirr
02-02-2014, 05:45 AM
Hi Friends !


now ,after more than two years of swapping between the original JBL Titanium vs the Radian Aluminium :

i prefer the Radian Aluminium diaphragm !

on the little bum cheek horn the original JBL Titanium sometimes sounds little harsh to me and my friend.He own the same 4425 in his Studio and also bought the Radians too , so we can compare the Speakers in our different rooms & equipment !

This little harshness is not audible on every record. For Example there are some good & bad remaster albums and original Cds of the 80s like the Talk Talk / genesis / some New Order / depeche Mode that sounds a bit critical to my ears.

I know, the remaster do not help much on bad records, sometimes it strengthened the critical frequencies.
I often compare such critical Tracks with all my reference Headphones Beyerdynamic T1, Sennheiser HD 650, AKG K701 & SPL Phonitor Headphone-Amp too.
With the headphones this harshness is still there too, but it does not fatigue my ears like the JBL Titanium !
On my Radian this peaks sounds the same forward, same attack etc. but less fatigue!
On our Phonic dB and spectrum meter i can not see a difference in this frequencies !
I think the better sound of the Radian depends on the 'better' damping/decay of the Aluminim. it does less 'ring' ... the reason why Guido coated the JBLs Titanium with Aquaplas....

Perhaps the reason why the outstanding Strauss Monitor SE-MF2 is also equipped with Aluminium Diaphragm ..... ;-)

... no beryllium TAD driver used there ! ;-) i guess this Strauss Se-MF2 Monitor is fitted with JBL Horn combined with TAD Bass-Driver...

But all this BIG monitors are to Big for my small room 16qm with 2,50m listening position :-(

______________________________________________

Because of this "space problem" i will open a new thread about smaller Monitors like 4425, 4312....
i will show you my improvements/enhancements of our 4425 & 4312

regards
Andreas