Adding the Hartsfield Horn and Driver to 4345

[ngccglp]

So I gathered the problem is with the 2441 and not 2440 because of the diamond surround?

also I noticed many of the early 2-ways are crossed at 500 hz

[Lee in Montreal]

So I gathered the problem is with the 2441 and not 2440 because of the diamond surround?

also I noticed many of the early 2-ways are crossed at 500 hz

Diaphragms between 2440, 2441, 2445 and 2446 are interchangeable. I have among other sets, a pair of 2441 on which I have fitted some Radian diaphragms, which are perhaps one of the two aftermarket diaphragms withh good results on a JBL compressor (including TrueExtent). The Radian diaphragm seems to have a polymer suspension which will not crease/crack, like an aluminum suspension. I think the titanium diaphragms also will not crack as easily...

[Mostlydiy]

I used the 2441 in my horn crossed at 450-500(24db slope) without a problem. I was feeding it with a 7W SET and thats enough to be able to play very loud, especially considering I use it in a "home environment". I do push the amp from time to time though

I currently use the 2482 and it can cope with a much lower cutoff but with that driver a 2 way wont work since they dont have much output over 5k.

The 2441 is an excellent driver and above 500Hz it should fit your "experiment" perfectly. I do believe that you need a baffle to that horn though to be able to make it go that low and I also think that crossing it directly to a 2245 is to much to ask for. A 15" would work better.

/Mostly

[ivica]

In theaters where the spl is usually high, didn't the 2445 go down to 500Hz coupled to a 2360 horns, and twin 2226 below (JBL 4675 system)? The horn is useable down to 350Hz to support that 500Hz crossover.

Hi Lee,

Do not forget that 2445 has Titanium diaphragm (diamond-shaped surround) not Aluminum as 2441 (diamond-shaped surround).

Look at the:
http://www.audioheritage.org/vbullet...ll=1#post29097

"......The following information is courtesy of JBL -

"The fatigue life of materials depends on amplitude of deflection. There is also a threshold. Meaning that if a diaphragm never sees more than a certain level it will never fatigue."
"It was felt that these diaphragms (aluminum) would probably last 2 hours at full power before starting to crack. The de-rating we believe to be that the life will extend about 10 times for each halving of power."
"The whole thing is of course complicated by spectrum. The above assumes the 2" drivers crossover around 1,000 Hz and the 4" drivers about 500 Hz."
"Titanium has about 10 times the fatigue resistance of aluminum. However the threshold is much higher as far as never fatiguing. Aluminum continues to fatigue at very low levels."
"The stress in the diamond surround is higher and thus would fatigue easier."
"The basic improvement of the diamond surround is that it moves the second resonance way up to 17,000 Hz or more. So they are simply broader band."..........."

May be I am wrong but diaphragm amplitude is inverse-proportional to the frequency squared ( two times less frequency four times larger amplitude ),
see: http://www.diyaudio.com/forums/subwo...ml#post1054013

so (in ideal case) (under the same SPL) diaphragm amplitude at 500Hz would be about 2.5 times larger then at 800Hz...
not to mention that the music has usually more amplitude at the lower frequency.

Reagrds
Ivica

[Lee in Montreal]

100% correct Ivica. As usual. ;-) My 2360 horns are bolted to some 2445 with those JBL titanium diaphragms (original set-up). I have reserved the 2441 with Radians for the 2397. My set of 2440 has aluminum diaphragms and not used (well, they were used with the 2350 which is a very, very efficient 500Hz horn requiring very little watts...)

[ivica]

1..... I have reserved the 2441 with Radians for the 2397. My set of 2440 has aluminum diaphragms and not used (well, they were used with the 2350 which is a very, very efficient 500Hz horn requiring very little watts...)

Hi Lee,

I have tried some 2441 with the JBL (Aluminum Diamond suspesion) and 2441 with the Radian (aluminum . poly...suspension). Up to about 10kHz+
they behave almost the same, but over 10kHz JBL outperform (in FR flatness) Radian very much.


Regards
Ivica

[ngccglp]

Hi all,

just to provide an update on my project. The biamping option did not sound as good and coherent. So I sourced for a 3115A and everything just falls in place nicely.

[ngccglp]

The instruments pitch is more true... I think this is the advantage of 2 way over 4 way... But power handling definitely behind 4 way.

[Mannermusic]

The instruments pitch is more true... I think this is the advantage of 2 way over 4 way... But power handling definitely behind 4 way.

Good show. Yes, instrumental timbre is the essence of true hi fi and that is mostly in the range above 1000 Hz (approx high C). Today, everything is more a matter of raw entertainment. Puffed up bass, etc., and above all, LOUD, LOUD, LOUD. Sounds like you are on your way. Bravo! Mike

[ivica]

So I gathered the problem is with the 2441 and not 2440 because of the diamond surround?

also I noticed many of the early 2-ways are crossed at 500 hz

Hi ngccglp,

I have no experience with 2440 drivers and their FR over 10kHz 9with JBL original diaphragm). From the old JBL doc about 2440 & 2350 it is said:

"Frequency response, measured on a terminated tube, shall be flat within +/-5 dB from 500 Hz to 9 5 kHz.
On 2350 horn, +/- 3 dB from 500 Hz to 10 kHz referred to 1 kHz...."

regards
ivica

[ngccglp]

Thanks Mike and Ivica.

I guess in a home environment I would never play that loud to threaten the diaphragms of the 2441.

I also checked the library and jbl spec the 2441 can go up to 18 kHz. For classic jazz I really do not miss the tizz of the 2405. It sounds just right judging from the timbre of the double bass solo... It still has enough highs to give the double bass pitch and attack.

and Joe Pass Virtuoso sounds wonderful as I'm writing...

[Fangio]

Congrats, good choice.

I'm still enjoying the Hartsfield Horn and 2" Combo too, on top of / integrated in 4ways as main speakers. I'm using Be dias in them.



Cheers

[ngccglp]

Hi Fangio,

thanks for sharing. The scale of the 2241/2245 presentation cannot be matched by the stock 4345, biamp or otherwise. I find it hard to go back to stock 4345.

[Fangio]

... I find it hard to go back to stock

Exactly the same here. I think I know what you are hearing, 2" works fine at lower levels. Mine are tube driven.

I do have another pair of horns to try with the 2441s yet. Unfortunately they are too wide to put on the '43s, its just visually not that appealing. Oh well, another project still to come..

[Mr. Widget]

Having lived with and played around with the serpentine horn/lens and several others of the vintage and having listened to 4345s and 4343s on numerous occasions, had you asked before heading down this path, I would have said don't waste your time. Since you are enjoying these so much, I'm glad you didn't ask.


This once again proves that there is no one solution for everyone. Keep exploring and enjoying! ...And keep up posted!




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