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View Full Version : Phenolic diaphragms for my JBL 2441s?



Doogster
06-28-2008, 02:01 AM
Hi chaps

I've been using JBL 2441 midrange drivers for the past couple of years in round tractrix horns over the range 800Hz to 5kHz. They have wonderful dynamics and presence, but I hanker for my old Tannoy dual concentrics (in GRF cabs) in the midrange. The JBLs are a little lean, and I'd like some meat on my bones (which is what the Tannoys did so well, despite their other flaws).

Seeing as the Tannoys employed phenolic drivers in their midrange/HF horn, I thought I'd try some phenolic drivers in my compression drivers. The problem is that although I have some 2482 diaphragms, I don't have any 2482 drivers (nor can I get hold of any locally).

Does anyone know if there are any commerically-available replacement diaphragms made of phenolic (or similar) which would fit 2440/2441/375/376 drivers?

Many thanks. Doug

Maron Horonzakz
06-28-2008, 06:07 AM
What makes you think going to phenaulic will give you "more meat" You can xover lower with phenaulic but will loose bandwidth on top. All with the loss of clarity... Lots of trade offs. All have certain colorations of there own...."Remember If it moves it distorts",,, But you dont want it to distort absolutly.

speakerdave
06-28-2008, 08:24 AM
The phenolic diaphragms for the JBL 248X series do not fit in the 244X series drivers. They are not cross compatible.

cooky1257
06-28-2008, 10:00 AM
Hi chaps

I've been using JBL 2441 midrange drivers for the past couple of years in round tractrix horns over the range 800Hz to 5kHz. They have wonderful dynamics and presence, but I hanker for my old Tannoy dual concentrics (in GRF cabs) in the midrange. The JBLs are a little lean, and I'd like some meat on my bones (which is what the Tannoys did so well, despite their other flaws).

Seeing as the Tannoys employed phenolic drivers in their midrange/HF horn, I thought I'd try some phenolic drivers in my compression drivers. The problem is that although I have some 2482 diaphragms, I don't have any 2482 drivers (nor can I get hold of any locally).

Does anyone know if there are any commerically-available replacement diaphragms made of phenolic (or similar) which would fit 2440/2441/375/376 drivers?

Many thanks. Doug

Hi Doug,
I'm just curious as to which DualConcentrics you refer.
The 12" and 15" Golds/HPD's had Duralumin hf diaphragms.
Cheers
Cooky

Doogster
06-28-2008, 07:14 PM
The phenolic diaphragms for the JBL 248X series do not fit in the 244X series drivers. They are not cross compatible.

Thanks, I'm aware of that, hence my enquiry as to whether there any other diaphragms out there which would fit the 2441s.

Cheers. Doug

Doogster
06-28-2008, 07:16 PM
What makes you think going to phenaulic will give you "more meat" You can xover lower with phenaulic but will loose bandwidth on top. All with the loss of clarity... Lots of trade offs. All have certain colorations of there own...."Remember If it moves it distorts",,, But you dont want it to distort absolutly.

Hi, I think I suffer from audiophilia nervosa, so I therefore have an insatiable desire to upgrade and/or change my speakers on a regular basis. LOL. But anyway, I hanker for my Tannoys, but only in the midrange. I guess I'm after something warmer and more seductive. The JBLs do wonderful things, but they do sound a tad lean at times. I want to keep my crossover points (800Hz and 5kHz).

Cheers. Doug

Doogster
06-28-2008, 07:18 PM
Hi Doug,
I'm just curious as to which DualConcentrics you refer.
The 12" and 15" Golds/HPD's had Duralumin hf diaphragms.
Cheers
Cooky

Hi, I had 15 inch Golds. I was always under the impression they used phenolic or impregnated linen or something similar. I could be wrong.

Cheers. Doug

cooky1257
06-29-2008, 07:47 AM
Hi, I had 15 inch Golds. I was always under the impression they used phenolic or impregnated linen or something similar. I could be wrong.

Cheers. Doug

Hi Doug,
I trawled back over some Yahoo Tannoy posts from last year and found we've corresponded via your 'better than tannoys' thread(still a Tannerd at heart then;-)If you look at my avatar you'll see where I've ended up-spooky eh?
Here's the oracle of all things Monitor Gold
http://www.44bx.com/tannoy/hfunit.html
Cheers
Cooky

Akira
06-29-2008, 07:27 PM
There are no phenolics for the 2440/41.
But, I do agree with you, there is more as you say, "meat" in the operating range with a trade off of HF response.
When speaker response was more limited in the 'olden days' and P.A. systems were commonly 4 & 5 way affairs, most of us live guys would use a phenolic for the upper mid range for that very reason, with a metal horn diaphram on top. Thus the popularity of 2482's. The best of them all (IMO) was the 1" 2470 phenolic. High SPL, great sound, more like paper up to 9-10K with slots on top! My personal fav...at least back then.

Pic below shows one side of right stack with the lense plate covering the shorter 'near stage' throw & the radials covering the longer
throw to the outsides of the stack.
mid/high 'near stage' 2x12" compression loaded mid with 2441/large slant plates (2404 added later)
mid/high 'far stage' 2x12" compression loaded mid with 2470/ 2405 (x2)
Compression loaded Bass in middle 2x12" ATC 2xJBL2225

Doogster
06-29-2008, 08:10 PM
There are no phenolics for the 2440/41.
But, I do agree with you, there is more as you say, "meat" in the operating range with a trade off of HF response.
When speaker response was more limited in the 'olden days' and P.A. systems were commonly 4 & 5 way affairs, most of us live guys would use a phenolic for the upper mid range for that very reason, with a metal horn diaphram on top. Thus the popularity of 2482's. The best of them all (IMO) was the 1" 2470 phenolic. High SPL, great sound, more like paper up to 9-10K with slots on top! My personal fav...at least back then

Hi Akira

Thanks for your reply. I actually have a pair of 2470s without diaphragms, but I had discounted them as being inferior to the 4 inch drivers. Perhaps I should check them out further. One of the drivers has a defect on the top structure where the diaphragm sits, so it might be a waste of time (I might post a pic to see what you guys think).

Cheers. Doug

Doogster
06-29-2008, 08:12 PM
Hi Doug,
I trawled back over some Yahoo Tannoy posts from last year and found we've corresponded via your 'better than tannoys' thread(still a Tannerd at heart then;-)If you look at my avatar you'll see where I've ended up-spooky eh?
Here's the oracle of all things Monitor Gold
http://www.44bx.com/tannoy/hfunit.html
Cheers
Cooky

Hi Cooky

Yes, I think I will always be a Tannerd at heart, even though I sold my Tannoys six months ago (sob, sob). I've never felt such remorse at parting with any other speakers I've owned (including the mint pair of Quad ESL 57s I had).

Cheers. Doug

subwoof
06-29-2008, 08:38 PM
I also used the 2470 for just about everything. It was the only driver that tolerated mistakes / screaming vocals and just who the F*%@ needed above 10K in a stage monitor?? An added advantage was corrosion resistance for the inevitable beer dousing.

For the few big outdoor gigs we had the 2482 on long throw community horns ( squirrel killers ). It was for vocals only ( ran the mix from an aux send ) and worked great.

As far as the "meaty" issue the biggest problem I found was the horn's performance at or near the cutoff made the real difference. If your horn is too short, no diaphram will correct this.

Another simple alternative is to use the coated 2445 diaphram. The coating really helps the "harshness" and it is quite robust at high SPL's.

The part number is D8R2450SL for the smooth and -1 for the ribbed.

sub

PS - those "perkins" bins were fine for 150 to 600 but you really needed the double scoops or leviathans ( with extenders ) to get those bass notes...

4343
06-30-2008, 12:50 PM
I also used the 2470 for just about everything...
An added advantage was corrosion resistance for the inevitable beer dousing.
...
...

When I bought my pair of 2470's in the late '70's, the sales guy at Leo's told me that the 2420 would "eat it" long before the 2470... He was right, I did have to replace the AL dia in one of my 2420's, while the 2470's kept right on going, even after being driven hard enough to hit the phase plug... Unfortunately one of the 2470 diaphragms was corroded away (copper wire just gone) when I opened them last year, now I have titanium in 'em, with a spare phenolic. Must have been that gig on the Russian river with all the fog that did 'em in, that and not drying them out after I guess. 2461's still going strong though! Heard 'em hit the phase plug when a performer dropped a mic just a few months ago too!

I've noticed that some 1" dia's have small spacers under the mounting screws that forms a set of three gaps between the mounting points. Is that for better airflow past the VC? All of my phenolic ones have them, but none of the cracked AL ones I have in sight do. Not sure about the working AL's or the Ti's...

hmolwitz
06-30-2008, 07:29 PM
I just picked up a pair of Tannoy monitor Gold 12's, one has a bad diaphragm. I examined it very closely and it is indeed aluminum 2"vc with roundwound aluminum wire spliced to copper at the former, Tannoy crosses these at 1000. Same phragm for the 15s