JBL 2441 vs 2445 vs 2446

[Lee in Montreal]

I am about to purchase a pair, of the three models mentionned, to be used with 2350 and 2397 horns for home duty (no pea). Which one sounds the best and has the lowest extension?

[1audiohack]

Were it me, diaphragm materials aside, it would be 2446, 2441 then 2445. I don't have any conclusive evidence to display to support that as yet. I don't know if there is any difference at low frequency, none that I've noticed anyway but I don't stretch mine to either extreme.

[Mr. Widget]

I am about to purchase a pair, of the three models mentionned, to be used with 2350 and 2397 horns for home duty (no pea). Which one sounds the best and has the lowest extension?If they are all stock and running up to spec, I would go for the 2441 due to the aluminum diaphragm, if you would consider going with a Be diaphragm then all things considered, I would go with the 2446 because of it's more advanced phase plug... that said, I am not sure if the newer phase plug will mate well with the 2328 throats that those two horns use. It very well may be a great match, but since they are different generations they may not be ideal. If that proved to be the case then I would go with either a 2441 or a 2445 with Be over a stock 2441.


Widget

[martin_wu99]

If they are all stock and running up to spec, I would go for the 2441 due to the aluminum diaphragm, if you would consider going with a Be diaphragm then all things considered, I would go with the 2446 because of it's more advanced phase plug... that said, I am not sure if the newer phase plug will mate well with the 2328 throats that those two horns use. It very well may be a great match, but since they are different generations they may not be ideal. If that proved to be the case then I would go with either a 2441 or a 2445 with Be over a stock 2441.


Widget
agree with you,and 2440 for another choise.
why pay such attention to low extend?they are high drivers:confused:

[Lee in Montreal]

agree with you,and 2440 for another choise.
why pay such attention to low extend?they are high drivers:confused:

"Low" is a relative notion in this case. "Low" could be 300Hz.

Lee

[Mr. Widget]

"Low" is a relative notion in this case. "Low" could be 300Hz.

Lee300Hz is extremely low for a compression driver. To go that low you should consider the phenolic diaphragmed large format JBLs like the 2482 or 2485. Unfortunately you lose the benefits of the extremely low mass and very high frequency break up mode of Be.

But then again, why are we discussing 300Hz and the two horns you mentioned above?


Widget

[Lee in Montreal]

So, 2446 with original Beryllium diaphragm sounds the best?

Lee

[JeffW]

So, 2446 with original Beryllium diaphragm sounds the best?

Lee

The Be diaphragms aren't JBL products, they are aftermarket and over twice as expensive (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=genem&Category_Code=Truextent-Diaphragms) as even the aluminum JBL diaphragms. (http://www.speakerrepair.com/mm5/merchant.mvc?Screen=PROD&Store_Code=genem&Product_Code=10-254&Category_Code=JBL-Diaphragms)

[Lee in Montreal]

But then again, why are we discussing 300Hz and the two horns you mentioned above?

Because if the driver has "something" happening at 300Hz, it means I will be fully operational at 500Hz with a 2350 at 12db cut-off. ;)

[Mr. Widget]

Because if the driver has "something" happening at 300Hz, it means I will be fully operational at 500Hz with a 2350 at 12db cut-off. ;)Along those lines, I have found that "derating" horns is the easiest way to improving their sound... say using an Altec 511 as an 800Hz horn instead of it's rated 500Hz, an 811 as a 1200Hz horn etc... I just picked the Altecs as they are logically named and an easy choice, but the same is true of the two horns you are looking at... increasing the crossover frequency will make them sound better. By better, I mean less "horn like". There are certain qualities that we associate with horns... moving the crossover frequency up a full octave or two from it's cut off frequency makes the horn sound less constrained and squawky.


Widget

[more10]

A pair of pretty nasty horns (http://translate.google.com/translate?js=n&prev=_t&hl=sv&ie=UTF-8&layout=2&eotf=1&sl=sv&tl=en&u=http%3A%2F%2Fwww.hififorum.nu%2Fforum%2Ftopic.as p%3FTOPIC_ID%3D82919&act=url). The original Swedish thread is fed through google translate, hilarious result :-).

That horn with a 248x will sound fantastic I believe.

[Lee in Montreal]

Wow. Impressive 250Hz. And in term of size, we are approaching this. :eek:
So, I guess that size really matters. ;)

51259

[more10]

Size and shape. I believe one should use Tractrix or LeCleach for midrange.

[4313B]

Wow. Impressive 250Hz. And in term of size, we are approaching this. :eek:
So, I guess that size really matters. ;)

51259Ok... now I know you guys are ill...

I didn't alt-tab out of this website fast enough and a co-worker asked "What the hell was that!?" I showed her and she said "OMG! That's atrocious!" :rotfl: Then we got into this protracted conversation about this illness. She still doesn't understand but at least she gave it a go.

[grumpy]

I didn't alt-tab out of this website fast enough and a co-worker asked "What the hell was that!?" ...

I know -you- guys are ill? :rotfl: Nice try there Missy.

[Eaulive]

she said "OMG! That's atrocious!" :rotfl:

Did you tell her that many _if not most_ of us think it's beautiful? :D

Which makes me wonder sometimes if the placebo effect doesn't come into play, that we find speaker are better sounding when they're big, kind of the same feeling you get about your car being faster and quicker after going out of the car wash :p

That is maybe the reason why bose sound so crappy:rotfl:

[Lee in Montreal]

Did you tell her that many _if not most_ of us think it's beautiful? :D

The only time my girlfriend told me "Oh Lee, it's so big!" is when she saw the 4520s in the basement. :eek:

[4313B]

Did you tell her that many _if not most_ of us think it's beautiful? :DNo because then she would get really confused... you see, she is beautiful. :rotfl:

[Eaulive]

The only time was girlfriend told me "Oh Lee, it's so big!" is when she saw the 4520 in the basement. :eek:

:lol_fit:

[4313B]

Ditto!

[Mr. Widget]

The only time my girlfriend told me "Oh Lee, it's so big!" is when she saw the 4520s in the basement. :eek:I guess I must be the odd man out here... I've never needed 4520s to hear that comment :bouncy: nor do I find large industrial horns to be beautiful... though, I do find these to be rather gorgeous.


Widget

[edgewound]

I guess I must be the odd man out here... I've never needed 4520s to hear that comment :bouncy: nor do I find large industrial horns to be beautiful... though, I do find these to be rather gorgeous.


Widget

That looks like something out of a Tim Burton movie.

[hjames]

That looks like something out of a Tim Burton movie.
Some kind of living thing that would hunt you down - alien insect or some such - gahhhh!

[grumpy]

Funny, i agree with all of the last three posts :D
(regarding the speaker:p, and except the 'gahhh' :))

Alas, the old Jadis Eurythmie contains no 2441, 2445, or 2446
(2225H though, IIRC .... big horn had a 'normal' cone driver)

Ah... here (for the audio-curious):
http://www.audiovoice-acoustics.com/forum/showthread.php?t=420

[jerry_rig]

Personally, I'd rather have the Magico Ultima:

[grumpy]

well, there ya go... or a house to live in :)

[ivica]

I am about to purchase a pair, of the three models mentionned, to be used with 2350 and 2397 horns for home duty (no pea). Which one sounds the best and has the lowest extension?

Concerning the dimensions of the mentioned 2350 Horn,
especially keeping in mind the problem about "time delay" differences between mentioned drivers and lower frequency (bass or/end mid-bass) and high frequency (UHF driver) and keeping in mind that you will use 'in-home" environment, I suggest you to think about 2308 Lens + 2311 Horn, and with the frequency above, say, 800Hz, up to say 8~10kHz

[Akira]

I am not sure about the quality of replacement diaphragms as I think they are after market only now. The 2445 was a dog of a driver. I used to own a whack of them for P.A. use and loved the abuse/power and shear SPL they could put out...practically unblowupable. But, fidelity.... give me a 2441!

[1audiohack]

I have one pair of 2445's that I bought used several years ago that sound as good to me as any of the 10 2441's I have (all with D16R2441's in them) and better than any of the 4 2446's (2 with D8R2445's and 2 with D16R2445's in them) I have. They have been the mainstay of my main livingroom system for a couple of years based soley on their sonic character.

A little over a month ago I embarked on a 2" driver / 4" diaphragm study that I am just about done / bored (just kidding) with and thought I should grab those old 2445's that I like and check them out.

I treated them as a black box and measured them for impedance, SPL, 2nd and 3rd harmonics with phase on all measurements and they looked to have D16R2450SL's in them, I took them apart to see, D16R2450's, I didn't even know I had a pair of them.

What diaphragms did you run in the 2445's?

[pos]

they looked to have D16R2450SL's in them, I took them apart to see, D16R2450's
You mean they were D16R2450SL or D16R2450 ?

I can't wait to see the result of your experiment!
I wish you had a 2452 core to include in your study (with an adaptor)! The Radian 950PB cores would also be an interesting case (Guido likes them better than the JBL, and they have that 5-slit phase plug...).

Finally, you could add some aquaplas to those Be diaphragms to complete the experiment ;)

[1audiohack]

Just the standard D16R2450's, they are suprizingly well behaved. That's one more pair of diaphragms in the mix!

I think JeffW is sending a 2452, the test pile just keeps getting bigger!:D

[JeffW]

I think JeffW is sending a 2452, the test pile just keeps getting bigger!:D

Ooops, forgot that one. I'll send it out tomorrow!

[1audiohack]

Thanks, when it comes time to send it all back at least I'll get UPS 100+ pound weight break!:p

[Lee in Montreal]

Lots of very good comments in this thread. Despite the mild comments, I still ended up buying two 2445s for $125 each, with original JBL diaphragms. The intention is to "appreciate" them as they are for a while, and then find some better diaphragms along the way.

Also realizing that I have no choice but going to a four way system and needing to buy another active crossover, unless I make a dividing network (with L pad) between the 2445 and the 2405 with crossover at around 8KHz, and keep running one 3-way active crossover only. The positive point is that it is much cheaper to make a crossover for high frequencies than low ones... :D

[1audiohack]

Just the standard D16R2450's, they are suprizingly well behaved. That's one more pair of diaphragms in the mix!

I need to revisit these 2445's, after talking with a couple of forum members it is probable that I incorrectly identified the diaphragms, I am reasonably sure they are Ti, but they are smooth, not ribbed as apparently the D16R2450 diaphragms are? This one looks like an uncoated D16R2452SL by sight and measurement. I have a 2452H here that I need to get apart, I will see what that one looks like, another possibility is the diaphragm that comes in the 2451 I guess.

What ever they are they sound and measure good.

[grumpy]

So ignoring phenolic and specialty consumer drivers,
the 4" dia seem to be assignable to 5 categories
(other variations seem to only be impedance (8/16) and included
hardware):

Al concentric surround/smooth dome (2440)
Al diamond surround/smooth dome (2441)
Ti diamond surround/smooth dome (2445)
Ti diamond surround/ribbed dome (2446)
Ti diamond surround/smooth dome/aquaplas (2450SL)

...the last three being not limited to the example driver listed.

Does that sound about right?

[1audiohack]

Thank you. I will have to look again, it's all a blur now.

[subwoof]

Slight edit:

Al concentric surround/smooth dome (2440)
Al diamond surround/smooth dome (2441)
Ti diamond surround/smooth dome (2445)
Ti diamond surround/ribbed dome (2446)
Ti diamond surround/smooth dome/aquaplas (2450SL)

should be:

Al concentric surround/smooth dome (2440)
Al diamond surround/smooth dome (2441)
Ti diamond surround/smooth dome (2445)
Ti diamond surround/ribbed dome (2446 / 2450)
Ti diamond surround/smooth dome/aquaplas (475)
( there was no pro model 2" exit with a coated dia )

the 2450SL ( coated, smooth Ti ) was a 1.5" exit - and it had a different mounting bolt dia than the non-coated 2451. 2450SL-a was the coated, ribbed Ti.

The newer 2452SL has the coated, smooth Ti but has a pair of special push terms added to a stock 2450SL dia.

:cheers:

[1audiohack]

Ok the 2445's that I like have D16R2445's in them, Ti, diamond surround, smooth dome.

Thanks guys!

[more10]

the 2450SL ( coated, smooth Ti ) was a 1.5" exit - and it had a different mounting bolt dia than the non-coated 2451. 2450SL-a was the coated, ribbed Ti.

The newer 2452SL has the coated, smooth Ti but has a pair of special push terms added to a stock 2450SL dia.


But will these go into any 2" exit driver?

[jerv]

But will these go into any 2" exit driver?

D8R2450SL diaphragms fits into all 2"exit drivers. I use them in 2445's with very good results.

2452SL diaphragms have different (integrated) terminals, and does not fit 2" exit drivers.

[pos]

these terminals can be removed without problem

[grumpy]

... and added. I've put a 2450SL dia in a 2452H body. I just reused the rubber 'plugs' and threaded terminals.

The 'different mounting bolt dia' referred to by 'beer is for the horn/driver interface,
not the diaphragm.

I haven't tried the TrueXtent dias in the 2452 body, but IIRC, someone here has
(perhaps requiring a trim of the rubber plug/gasket things, as the dia frame seems
a bit taller... I haven't measured them or looked it up).

[pos]

Cooky did it without major issue:
http://www.audiosmile.com/forum/showpost.php?p=289732&postcount=87

[JeffW]

I wish he would have taken one more set of pics showing how he hooked the terminals up.

[pos]

The rubber part will just stick out of the cap a bit, but still maintain seal :
http://www.audioheritage.org/vbulletin/showthread.php?26904-WTB-2452-SL-diaphragms&p=283226&viewfull=1#post283226

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=44868&stc=1&d=1269119900

[Herman Chigrin]

Has anyone compared the 4" Be diaphragms between the 2240-2451 JBL models and if the sonic character changes through the driver models?
Herman

[Earl K]

Has anyone compared the 4" Be diaphragms between the 2240-2451 JBL models and if the sonic character changes through the driver models?
Herman


I believe LHF members sebackman (& maybe POS ) have the most experience to offer on that subject.

:)

[engineerjoe]

Has anyone compared the 4" Be diaphragms between the 2240-2451 JBL models and if the sonic character changes through the driver models?
Herman
I might be mistaken about your post here. Do you mean the 2440-2451 JBLs?
This is obviously just my opinion!
I run my stuff for PA use. I have had 2440s, 2441s, 2445s, 2446s, and now I finally got a single 2450 to compare. I retired years back and left the field.
The phase plugs in the drivers changed over the years and there was definite differences (improvements) in the higher frequencies (like from 10 - 20k).
In the old days people used the bullets or slots, as we called them, to improve high freq on the 2440s. When I bought 2441s I ran them alone up top.
I now have 2 x 2445 and 2 x 2446 drivers right here and one of them sounds much better up high than the other 3 do? I had hoped to actually hear the difference in the phase plugs between the 2445 and 2446. I bought them used and can't verify the diaphragms other than sonically to my ears. I have the main EQ rolled up in the highs to compensate.

I don't have my old 2440/1 models anymore to compare with. Sold them off when I retired.
Can I ask what Be diaphragms are? I'm not familiar with the letters.
I haven't compared the 1 1/2" drivers against the 2". Years back I compared the JBL 1" 2425/6 to the 2" 2445/6. I felt the 1" sounded too harsh and the 2" had better much clarity in large rooms Bars and Auditoriums. It maybe preconceived by me but I still feel the 2" is best for large PAs. I am still reluctant to try the 1 1/2" drivers against the 2" versions for that reason.
Almost everyone's posts here seem to be about home use. Being retired I finally use my stuff in the house and yard and I stand firm in my beliefs. I may be too old here.

[Robh3606]

I am still reluctant to try the 1 1/2" drivers against the 2" versions for that reason.

They are identical difference being throated vs. throatless. Drivers like the 2450 vs 2451 are a perfect example same phase plug the 2450 has the typical throat with a recessed screen. On the 2451 there is no throat extension and the screen is right there.

Be stands for Beryllium a very expensive diaphragm material used it TOTL systems.


http://www.lansingheritage.org/html/jbl/specs/pro-comp/pro-comp.htm


http://www.audioheritage.org/vbulletin/showthread.php?33568-476Mg


Rob:)

[engineerjoe]

Thanks Rob.
So is the final exit throat diameter of the 2450 2" and the throat of the 2451 1 1/2" or do I have that wrong?
I'm interested if it adds harshness to higher output volumes coming out of a smaller exit.
I saw that they can use the same diaphragm and I didn't know that.
I recently got even more confused when I thought I saw a used set of 2450 drivers without the throat extension?
Then there's another version 2450sl? which I believe is 1 1/2 throat?
It will be fun to compare and see the sonic differences.

[Robh3606]

So is the final exit throat diameter of the 2450 2" and the throat of the 2451 1 1/2" or do I have that wrong?

Yes


I'm interested if it adds harshness to higher output volumes coming out of a smaller exit.

The 2" throats had a decades old flare rate. The new throatless design is actually supposed to reduce distortion. There is a Technote about it

http://www.cieri.net/Documenti/JBL/Technical%20Notes/JBL%20Technical%20Note%20-%20Vol.1,%20No.31.pdf



I recently got even more confused when I thought I saw a used set of 2450 drivers without the throat extension?
Then there's another version 2450sl? which I believe is 1 1/2 throat?

You are not alone I got confused as well, there are 2 versions.

Rob:)

[engineerjoe]

I did get a set of the new type bells for comparison. One thing for sure, it beats the heck out of lugging around the old huge aluminum models.
84998

[engineerjoe]

I have these for comparison as well.
84999
85000
85001
85002
BTW I was going to use those 1 1/2" horns for stage monitors. If they throw well and sound good, they'll be on FOH.

[JeffW]

I recently got even more confused when I thought I saw a used set of 2450 drivers without the throat extension?
Then there's another version 2450sl? which I believe is 1 1/2 throat?


The 2450SL is similar to the 2451, different mounting bolt pattern, both 1 1/2" exit (no throat on either). I think it's sebackman tried both the 2450SL and 2451 w/Be phragms and preferred the 2451 by a slight bit.

I don't see anyplace selling the Truextent Be Diaphragms. Reconing speakers has them listed with call/email for price/availability. Used to get them for $500 ea, seems like I heard $800 ea recently?

https://reconingspeakers.com/product/bex4016-truextent-beryllium-diaphragm-16-ohm-copy/

[engineerjoe]

for anyone interested in opinion!
The Selenium drivers on those EV bells sound very sweet to me. They aren't harsh and seem nicer close up in the house at high freq.
Outside I had the system turned up a bit, and to me, the 2" 2445 on their bells sounded like they cut thru better in the upper mids to highs, and still did not sound harsh in all freq. heard (used above 1200? if I remember the points?).
That's where I noticed that a few of the 2" drivers seemed to be rolling off early and I boosted the EQ at the top of the range. As I stated, I just don't know what diaphragms are in what because it was all bought used. One of them sounded much better up high and I wish I could ID that diaphragm.
I didn't mark the driver so I would have to set it all up again for a good listen. To be fair, I would also have to swap out stuff to eliminate any other variables in the system. I just found it interesting that 1 of 4 drivers sounded better up high.
I too should wait for others who have tested to chime in here. It's just my ears and I am getting old! Urrggg. sorry for the rambling...