Adding the Hartsfield Horn and Driver to 4345

[ngccglp]

Hi,

I have been offered a pair of hartsfield horn/lens with 2441 drivers. I am thinking of a project to put the hartsfield horn on top of my 4345 and create a 2 way system using active crossover and biamping the 2441 and 2245 only. Crossover frequency would probably be 500-800 hz.


Based on your experience with Hartsfield, Do you think I will get good results from this combination?

Thanks.

[speakerdave]

What is it you are finding deficient in the stock 4345?

[Earl K]

Hi,

I have been offered a pair of hartsfield horn/lens with 2441 drivers. I am thinking of a project to put the hartsfield horn on top of my 4345 and create a 2 way system using active crossover and biamping the 2441 and 2245 only. Crossover frequency would probably be 500-800 hz.


Based on your experience with Hartsfield, Do you think I will get good results from this combination?

Thanks.

Well, based on my experience, I'd say that you are in for a disappointment .

But apart from my nay-saying, I think you should buy this driver-horn combo & then experiment all you can / it's the best way to learn ( as long as you can afford the tuition fees ) .

:)

[martin2395]

So you want to drop the 4-way 4345 and make it 2-way with the 2245 on the lows?

If I were you I'd put the 2441 in the 4345 and use the H93 / 2312 + lens combo like in the 4355.

[speakerdave]

The 2441 mounted on the 2311 won't clear the dogbox for the 2122. But I agree with that approach. The 2450 will work, and with a dusted diaphragm it is a significant improvement. Imagine what it would be like with Be installed! I also tried some TAD 2001's in mine, and that was very nice. You also might try some new aluminum 2421 diaphragms. I understand what you mean about the midrange CD as is, though.

[ngccglp]

I've heard the 2-way hartsfield and thought that it was a very different presentation compared to the 4345. Bulk of the difference I think boils down to the HF driver and I am aware of the limited HF extension of the 2441, but there is something special about the 2-way design that is very appealing. There's so much more "texture" to the music compared with the 2421.

Also check out the model S300S in this link:

http://www.bellwoodlansing.co.jp

[martin2395]

The 2441 mounted on the 2311 won't clear the dogbox for the 2122. But I agree with that approach. The 2450 will work, and with a dusted diaphragm it is a significant improvement. Imagine what it would be like with Be installed! I also tried some TAD 2001's in mine, and that was very nice. You also might try some new aluminum 2421 diaphragms. I understand what you mean about the midrange CD as is, though.

Oh yes they will, try harder!!

(just kidding :D)

Not sure how big the 2122H dogbox is but the 2441 fits in my 4343A if you chip off a bit from the top of the dogbox.

[ngccglp]

Just collected the hartsfield horn/lens with the 2441. The 2441 is a monster! Got to be careful it does not cause any dents on my 4345.

Will borrow a 5235 with 800 hz card tomorrow to experiment. But I think 500 hz would probably be better.

Will post picture soon.

[speakerdave]

Oh yes they will, try harder!!

(just kidding :D)

Not sure how big the 2122H dogbox is but the 2441 fits in my 4343A if you chip off a bit from the top of the dogbox.

I might have been able to do the same thing, but was reluctant, and because I had the 2450's I never had to make that decision.

[ngccglp]

62560

[ngccglp]

62561

[ngccglp]

62562

[ivica]

Just collected the hartsfield horn/lens with the 2441. The 2441 is a monster! Got to be careful it does not cause any dents on my 4345.

Will borrow a 5235 with 800 hz card tomorrow to experiment. But I think 500 hz would probably be better.

Will post picture soon.

So You want 2245 to push to 500Hz (?), my be too high, or can try with 2242 instead for over 300Hz bass usage.

regards
ivica

[ngccglp]

The tech sheet for 2245 says recommended crossover frequency 800hz. I'm currently using 800 hz card and it sounds quite good. But I want to hear more of the 2441 and think 500 hz is the way to go. Just like hartsfield. Better for the 2245 too.

[ivica]

The tech sheet for 2245 says recommended crossover frequency 800hz. I'm currently using 800 hz card and it sounds quite good. But I want to hear more of the 2441 and think 500 hz is the way to go. Just like hartsfield. Better for the 2245 too.

Hi ngccglp,

You have to be aware of that 2241J has aluminum-diamond-shape diaphragm suspension,
so such combination is fragile for larger diaphragm amplitude, and can be destroyed.

I have done some FR measurements 2241J-AL with 2311 horn (without 2308 lenses)
and it can be seen that under 1200Hz there is not so good. may be 2311 is too small...but...

regards
ivica

[Mr. Widget]

I have done some FR measurements 2241J-AL with 2311 horn (without 2308 lenses)
and it can be seen that under 1200Hz there is not so good. may be 2311 is too small...but...
I don't think accuracy is the point of this exercise. ;)


Widget

[Mannermusic]

I don't think accuracy is the point of this exercise. ;)


Widget

:) Bravo! I still have a pair of those babies in the closet and get them out about once a year for yet another listen. Last time in my 43xx 4-way (my horns sit on top of a separate main cab so I can try anything at will). They ain't perfect, but they are fun. Big, symphonic - musical in spades. My fav for those, however, would be a tri-amp with 15" crossing at 700-800 Hz into 375 (2440) and then 7000 Hz into 077. Also, they love the Marantz 7 + Crown D style amps. Anyway, it's a great exercise and definitely worth pursuing. I'm gonna get 'em out again. Mike

[Mannermusic]

62561

You are missing the mandatory baffle that inserts between the horn and the lens. It's 2' wide and 8" high X 3/4" thick with a rectangular opening the size of the horn outlet. There was a kit available in the ancient past - MA25 - but you will be lucky to find it. However, it's not difficult to make. But, the horn will not work properly without the baffle. Not an option. Perhaps this is one of the reasons you so often hear negative comments re the sound of the horn. ;)

[Lee in Montreal]

The tech sheet for 2245 says recommended crossover frequency 800hz. I'm currently using 800 hz card and it sounds quite good. But I want to hear more of the 2441 and think 500 hz is the way to go. Just like hartsfield. Better for the 2245 too.

If you can get clean bass up to 300Hz with the 2245, then consider yourself lucky. 500Hz is way too high. Look at the cone. It is aquaplas'ed and very heavy. Personally, I wouldn't use a 2245 beyond 200Hz. If you are into "older" woofer, then the 2240 could do the job. And with a respectable Fs of 30Hz, it remains a good home woofer. And it goes higher than a 2245, cleanly. If you have a big horn, 500Hz can be your cut-off frequency. With the Hartfields, you may want to add a large baffle to get down to 500Hz.

Just sayin' ;-)

[ngccglp]

Hi guys,

definitely accuracy is not the goal ( that's why I want to be able to switch back and forth between this and stock 4345),

its for the passion and emotion of the music...

ok, I will fabricate the baffle. Can I confirm the dimensions is 2' x 8" x 3/4" thick?

Thanks.

[Lee in Montreal]

ok, I will fabricate the baffle. Can I confirm the dimensions is 2' x 8" x 3/4" thick?

Thanks.

And if you make that baffle bigger, it will lower the cut-off frequency, which is what you need to reach 500Hz. Even the huge JBL 2390 slants needed the rear baffle to reach 500Hz, and people were making them even bigger than original. No baffle, they were limited to 800Hz.

[Mannermusic]

Hi guys,

definitely accuracy is not the goal ( that's why I want to be able to switch back and forth between this and stock 4345),

its for the passion and emotion of the music...

ok, I will fabricate the baffle. Can I confirm the dimensions is 2' x 8" x 3/4" thick?

Thanks.

Yep - and digest Lee's insight above (#21). Baffles make a big difference - and they interact with the room as well so it is a "tuneable" device. There are many "toys" to try - you may end up building another enclosure to play with . . . we all do (don't hack up the 4345!). Remember, there is no perfect solution. Have fun. Mike

[ngccglp]

Ok.

Have Horn, Will Experiment ! :D

Thanks.

[ivica]

I don't think accuracy is the point of this exercise. ;)


Widget

May be You are right but this have to be in mid:

"...You have to be aware of that 2241J has aluminum-diamond-shape diaphragm suspension,
so such combination is fragile for larger diaphragm amplitude, and can be destroyed.
..."
I am sure that You know what had happened when 4" diamond-shape aluminum diaphragms had been shown for the first time by JBL....

Regards
Ivica

[ngccglp]

Does this mean that I should stick to 800 hz to limit the excursions of the 2441 diaphragms?

also , does the thickness of the baffle board matters? Can I use 1/2" instead of 3/4" thickness?

thanks.

[Lee in Montreal]

1/2" plywood will work. The 2390's baffle is soft 1/32" aluminum with wool felt at the front.

[ngccglp]

Thanks Lee.

[Mr. Widget]

Does this mean that I should stick to 800 hz to limit the excursions of the 2441 diaphragms?You can de-rate the max power level and go with a lower crossover, but to be safe 800Hz is more prudent.



Widget

[Lee in Montreal]

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.

http://i191.photobucket.com/albums/z127/spinefixr/S5002440.jpg

[grumpy]

Ti
steep slope

[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 :confused:

[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 :confused:

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/vbulletin/showthread.php?3233-Compression-Driver-Diaphragm-Longevity&p=29097&viewfull=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/subwoofers/89960-cone-movement-vs-frequency-2.html#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.



6265662657

[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 :confused:

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.

http://i268.photobucket.com/albums/jj35/MacFangio/jblnews/43432390quer.jpg (http://s268.photobucket.com/user/MacFangio/media/jblnews/43432390quer.jpg.html)

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..

http://i268.photobucket.com/albums/jj35/MacFangio/JBL 2350 Horns/th_DSC0043_2.jpg (http://s268.photobucket.com/user/MacFangio/media/JBL 2350 Horns/DSC0043_2.jpg.html)

[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!




Widget

[ngccglp]

Hi all,

Just went to listen to my friend's pair of Ocean Way HR3 speakers driven by custom external XO w what must have been 20 bands EQ. Driven by AR for horn, Viola for bass, AR for Sub. I must say that the basic character of the OW is very similar to the new JBL Studio Monitor sound. Despite its lack of a supertweeter, it has quite nice extended high frequency and cymbals still maintained that nice sparkle. Bass from the 15 inch woofer seemed to slightly lean and needs to be supplemented by the sub to sound full. Mid bass was bit lacking in absolute punch but overall a very nice sound indeed.

But for the price I would settle for a 4365 or M2 anytime. :D

Hi Widget, indeed. I did many A/B switching back and forth, the stock 4345 just sounds smaller and instruments lacks weight when compared with the Hartsfield Horn combination. Because the Hartsfield Horn Combination lacks the 2405, it is slightly rolled-off. Other than that it can't be faulted as being the more musical. My Ocean Way friend couldn't believe the bass he heard on the single 2245H when compared with his augmented 15 inch bass.

[subwoof]

No matter all the discourse on dia material, baffling, power, crossover, etc etc etc it STILL requires a DEEPER horn length to properly function in the crossover region....and the corresponding flare rate / mouth.

LOOK at the depth of the 2360 from mouth to driver exit...and it was STILL derated for use at 500hz!!!!

The laws of physics does not change no matter WHO writes the internet article, scientific paper or for that matter, the marketing people at JBL...

period.

[ngccglp]

Hi Subwolf,

i'm still puzzled, how did JBL Hartsfield crossover at 500 hz?

thanks.

[hjames]

So - that's all related to Wave length, which is frequency dependent, right?
The Frequency determines the length of the waveform in the air ...

High frequencies are shorter waveforms, lower frequencies are longer ...
so, the lower the freq, the longer the horn has to be ...


No matter all the discourse on dia material, baffling, power, crossover, etc etc etc it STILL requires a DEEPER horn length to properly function in the crossover region....and the corresponding flare rate / mouth.

LOOK at the depth of the 2360 from mouth to driver exit...and it was STILL derated for use at 500hz!!!!

The laws of physics does not change no matter WHO writes the internet article, scientific paper or for that matter, the marketing people at JBL...

period.

[ivica]

Hi Subwolf,

i'm still puzzled, how did JBL Hartsfield crossover at 500 hz?

thanks.


Hi ngccglp,

JBL 2440 (375) has different diaphragm suspension in comparison to the 2441,
so can allow larger diaphragm excursion (when the loading is not optimal, due to the horn size vs applied frequency range)

regards
ivica

[ngccglp]

Hi ivica, ok I got it now. So there is a trade off when jbl introduced the diamond surround.