JBL 2397 Curves

[Mr. Widget]

I recently bought an electro-acoustic measurement system called Clio. I still have a lot to learn about using it to do fancier measurements like THD, Polar Plots, etc., but I have been using it to do some basic frequency plots for the Project May effort and tonight I thought I'd give it a whirl on the popular JBL 2397 "Smith" horns.

Here is a plot of the JBL 2441 driver on the 2397 horn. The Blue plot is on axis and the Red plot is 30 degrees off axis. These plots have what is called 1/12th Octave smoothing. With smoothing it averages the response within the specified octave rate. The overall response is pretty flat (no speaker really measures flat at this resolution), and the 30 degree off axis response is surprisingly good. Realize that this horn is not really meant to be used below 800Hz.

Widget

[Mr. Widget]

Here is a comparison between the JBL 2397 and one of my Westlake clones. It is interesting how the the wider lips of the Westlake do seem to improve the lower response, but at a sacrifice at the top end. This explains why I always feel the need to EQ up a bit around 6-10KHz.

[Mr. Widget]

These plots are from the same measurements as above but with half octave smoothing. This is frequently the way we see response plots in catalogs as it looks better.:)

Widget

[Steve Gonzales]

Lovely piece of equipment there,Sir. Very interesting data too. With all due respect, I think you should be named Mr "Wizard". I've shown the drawings to some craftsmen I know and I'll be cookin' some test runs off those drawings you so kindly posted very soon. I love this new data because I really didn't know if there was truely a difference between the 2397's and the Westlake's . Can you plot spatially or is that a bad question? Also, when you say EQing, do you use an EQ in your main system (music). I have always got such a negative response when I tell friends that I use an EQ, but to my ears, when I use the EQ, the response is pleasing . I use both parametric and fixed band- subtlely . I am curious to know if you do too and to what extent, notch filter, full fixed band or parametric?

[Alex Lancaster]

:) That´s neat Widget!; Do You plan to compare the 2311/08 combo sometime?.

[paragon]

This is measured 12 years ago by "Audio-Technik" (Lowther Dist.) with a prof.
measure system.

[paragon]

This is my 2441 with the 2397. May use this from 800-10000 Hz.

Eckhard

[Earl K]

Yes indeed ,

- Nice stuff there Mr. Widget

FWIW - For General consumption; I'd go with 1/3 octave smoothing , along with 3db vertical scale increments . The reasoning ??? It was determined decades ago, that this is the most typical change in power and/or musical division ("resolution") that the majority of the population can sense ( hence the common adoption of the 1/3 octave RTA ) . Of course everyone has different personal calibrations. For Instance : I'm quite "aware" of broadlybased level-changes as small as .5 db when implementing a balance between components .

regards <> Earl K

[Mr. Widget]

Can you plot spatially or is that a bad question? Also, when you say EQing, do you use an EQ in your main system (music).
I do plan to do polar plots and waterfall plots at some point. I will need to get a turntable and a bit more experience using the system.

As for EQ. I have found the White 4400 1/3 octaves to sound pretty much invisible. I have tried a variety of other EQs and felt they did more harm than good. I obviously haven't tried all of the EQs out there, only a handful really, but anecdotally there seems to be a consensus that the rotary pot Whites which have recently been discontinued are among the very best if not the very best.

Widget

[Mr. Widget]

:) That´s neat Widget!; Do You plan to compare the 2311/08 combo sometime?.
I don't currently have one or any 1" drivers. If someone brings one by, I'd be curious to check it out with this objective measurement gear. Subjectively, I prefer the 2397/2441. A while back I had both and did AB comparisons and to my ears there was no competition. I suppose THD measurements comparing the big 2" 2441 vs. the 1" driver should be made too as that is likely a contributing factor.

Widget

[Zilch]

I don't currently have one or any 1" drivers. If someone brings one by, I'd be curious to check it out with this objective measurement gear.Now, you KNOW I have a nasty 'ol LE85 and a "special" horn for you to test. :D

Hang on. A coupla 2426's are on their way here on 2370A horns.

I'll strike while the toys are "hot," if you'd like to check them out....

[Mr. Widget]

Now, you KNOW I have a nasty 'ol LE85 and a "special" horn for you to test. :D

Hang on. A coupla 2426's are on their way here on 2370A horns.

I'll strike while the toys are "hot," if you'd like to check them out....
To quote the fearless leader, "Bring it on."

Widget

[4313B]

I recently bought an electro-acoustic measurement system called Clio.Very exciting! :yes:

[scott fitlin]

Impressive piece of electronics. Use it well.

:D

[lfh]

I do plan to do polar plots and waterfall plots at some point.

Thanks for posting those curves! It's most interesting to see the difference between the two flavours. I really look forward to see the polars and waterfalls later on. :yes:



Do You plan to compare the 2311/08 combo sometime?

As a matter of fact a 2441/2311/2308 vs 2441/2328/2397 shootout is on my to-do list, but it'll take a while since the 2308 lenses will ride in a '68 El Camino from LA to Stockholm. (Yes, I do have a pair of 2397s now - bought them yesterday! I'm sooo happy! :D )

[Alex Lancaster]

:) Widget: the 2311 is 2".

[Mr. Widget]

Yeah sure, whatever...:D

OK, so I wasn't paying attention. I would be interested in measuring one of those in comparison to the 2397.

If anyone could send me one with lens, (I bet I could borrow a lens locally) and the 2311 is a stubby little fellow so shipping wouldn't be much, I would be happy to run some curves of it. I could even do it with different baffle sizes to see the baffle effect.

Widget

[Steve Gonzales]

What is the suggested x-over point to the UHF driver. It seems that both the 2440 & 2441 have significant output well past the minimum x-over point of the 076 & 077 I would use. I realize that JBL made the N7000 and N8000's for this very application but due to my lack of knowledge, I can't help but wonder if using either a staggered (overlapped) x-over point or a custom 9-10k x-over point would allow use of the mid's substantial output past the typical 5-8k points and not waste that useable energy. Is there a dispersion problem or any other factors that prohibit this?

[Infredible]

In name of science you can get one of my 2308 for the plotting.

Fred.

[speakerdave]

I've got a spare 2311.

David

[Zilch]

:D Party!!!! :D

[Alex Lancaster]

;) Widget: ?

[Mr. Widget]

Excellent! Dave bring it by or ship it if you can't make it. Fred, I still have some of your Belgian beers, let's party.


Widget

[Ken Pachkowsky]

Some interesting plots Widgy. Made an attempt at doing a quick and dirty test of adding the 2405's to my Westlakes but failed. I tried using the HRX crossover up to 4.5k then crossing to the Ashly XR 1001 in 2 channel mode. I set a xover point of 8k and fed the lows to the 2426 on the small horns and the high side to the 2405's. The high side sounded fine but the low side was dead for reasons unknown (could be the XLR cables I picked up are wired opposite). I did not have time to trace before going on a business trip. We are def off now till Jan 15th so will try again today or tomorrow.

Ken

[lfh]

If anyone could send me one with lens, (I bet I could borrow a lens locally) and the 2311 is a stubby little fellow so shipping wouldn't be much, I would be happy to run some curves of it. I could even do it with different baffle sizes to see the baffle effect.

Wow, this is getting better and better! If you have the time, I think it would be extremely interesting to get measurements also without baffle and lens, as well as with baffle but no lens (at 0, 30 and 60 deg if possible...). All "in the name of science"!

I know that the 2311 needs the baffle - at least 12 in x 12 in according to the data sheet (BTW, I wonder how many guys that have used this exact size and put the horn in the middle ;)) and lens to function as intended, but the other day I listened to one without those and - not surprisingly - it sounded like the horn hater's worst nightmare. It would be interesting to see those curves...

[Chas]

Widget, this is too cool! Once you have a 2311/2308/2441 mounted on a baffle and measured, can you do an overlay on your 2397/Westlake graph?

Goes back to earlier PM's I had wth you. BTW: Can you measure harmonic distortion as well, or am I dreaming?:banghead:

[Mr. Widget]

BTW: Can you measure harmonic distortion as well, or am I dreaming?:banghead:
Yep. It will do 2nd and 3rd harmonic distortion in the Lite version that I currently have. If/when I spring for the whole package it will do up to 5th harmonic.


If you have the time, I think it would be extremely interesting to get measurements also without baffle and lens, as well as with baffle but no lens (at 0, 30 and 60 deg if possible...). All "in the name of science"! Well we will see. It is all possible given enough time. :)


I was just measuring my test amp. (an old Kenwood integrated) It was flat to 10KHz and down 0.10dB at 20KHz. Fun stuff. I measured it's second and third harmonic distortion too, but it is displayed in dB. I have the current version which is 6.5. Version 7 which was shown at the AES convention and should be out early in the year does distortion and linearity analysis and plots THD. It will also do wow and flutter analysis as well as a bunch of other tests. I might have to check out my old Oracle TT when V. 7 comes out.:bouncy:

Widget

[JustBuildLspkAS]

Hello Everybody.:)
I'm newface new JBLsfan and new member from Thailand.

:applaud: :applaud: :applaud: Thank you for many nice plots.....Waiting next plots



My system now.........Please check out my attatched pics.
4xLE15 (16Ohms).... with 7ft3 closed box and couple with 4 JBL passive radiators(still waiting 2nd pair of 2290s ....now I use D140Fs like the passive radiators)
2xLE85+H91
2x2405(0.2uF PP Cap in series the 2405s as super tweeter and parallel with LE85)
2x3110 ...800Hz Crossover

For my smallroom (11x 17 x 8 ft) these speaker can play lound with my DIY 2A3SE amp.

I planned to buy 2440+2328+2397 from my friend(I heared already and prefered them) and I'll have single 2441 soon.

I have a pair 2328 and for 2441 I'ld like tried to build 2397's copy by realwood(TEAK or redwood) ,
Everybody ,If you have some idea Please advise mee too.

[lfh]

Hello and welcome!

I think you have a very cool system and that you'll be pleased by the 2441/2397 combo.

In my current setup (active crossover @ 1.2 kHz, paired with 2405s with passive crossover @ 10 kHz) they have a "magnetic" effect on me: It's hard to stop listening! :)

As has been pointed out before in the forum, the wide horizontal dispersion may call for strategically positioned absorbers in a small room where otherwise reflected sound from the side walls could hurt the performance. Also the general rule of not running the horn too low in frequency applies of course, and Mr. Widget's measurements provide valuable info in this respect. As to tweeters, the 2405s you already have are a very good complement reflecting their polar characteristics that matches that of the 2397s, which yields a decent power response and a large sweet spot.

Regards,
Fredrik
Stockholm

[John W]

Welcome,
That is quite a setup in your picture. Building your own 2397 is a worthy project. I am just finishing up a pair myself.
This thread has a dimensional drawing of the horn.
http://audioheritage.org/vbulletin/showthread.php?t=5114
Try doing a search on 2397 for some of the construction techniques that have been used.

[Doc Mark]

Yeah sure, whatever...:D

OK, so I wasn't paying attention. I would be interested in measuring one of those in comparison to the 2397.

If anyone could send me one with lens, (I bet I could borrow a lens locally) and the 2311 is a stubby little fellow so shipping wouldn't be much, I would be happy to run some curves of it. I could even do it with different baffle sizes to see the baffle effect.

Widget

Hi, Widget,

I was perusing some old threads, and came upon this one, in which you had run some performance graphs on the 2397 + 2441 combination. Towards threads end, you were planning on comparing that combo to the 2311 + 2308 + 2441 performance. Did you ever complete that, Sir, and if so, where could I find the end results of your testing? This is in line with a question I asked earlier today, do whatever you gleaned from your testing and comparison, would be of great interest to me. Thanks, very much, and God Bless!

Every Good Wish,
Doc

[Earl K]

Doc,
- Here ya go, courtesy of 4313B ( some of us just know where to look ).
- ( It's the grey trace ) .
- The graphs are from this thread about the 475Be driver . (http://www.audioheritage.org/vbulletin/showthread.php?p=226117#post226117)

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=33790&stc=1&d=1218806961
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=33791&stc=1&d=1218806972

cheers><:)

[Doc Mark]

Evening, Earl,

Many thanks, and also to 4313B! It seems to me, that I've heard others say the 2397 sounds much smoother than some other horns, is that right? I'm not going to do anything, right now, but may do so somewhere down the line. Nice to have my ducks in a row, when and if I decide to jump into another pair of horns and adaptors. Thanks, again, and God Bless!

Every Good Wish,
Doc

P.S. There is one pair of 2397's, with adaptors, on FleaBay, right now. But, they don't look that nice to me. If I obtained a pair, I'd like them to be in outstanding condition.

[Mr. Widget]

I've heard others say the 2397 sounds much smoother than some other horns, is that right?I think so, but be aware that their wide dispersion requires careful placement and benefits proper room treatment.


Widget

[Mr. Widget]

Hi, Widget,

I was perusing some old threads, and came upon this one, in which you had run some performance graphs on the 2397 + 2441 combination. Towards threads end, you were planning on comparing that combo to the 2311 + 2308 + 2441 performance. Did you ever complete that...I never did measure the 2441s on other horns... I ended up selling the drivers.

I would take those early plots of mine with a grain of salt... these were some of my very first measurements and I wouldn't be at all surprised if they were not entirely repeatable. ;)


Widget

[Doc Mark]

Good Morning, Mr. Widget,

Many thanks for your further thoughts on this matter. Much appreciated. I will take a "wait and see" attitude on this, for now. As I wrote, the pair on FleaBay are not calling to me, as I do think they might have serious problems. I've asked the seller a very pointed question as to their condition, which had already been asked before and remained unanswered. Instead of responding as requested, the seller seemed offended by my asking this question again, and gave what seems like his stock answer to such things: Buy it now, or shut up and go away.... or, at least that's how his reply came across to me. I'd rather do business with someone who cheerfully and carefully answers any asked questions. "Time to buy, snooze, lose" doesn't get it, in my book!! ;):biting::blah:

Thanks, again, Widget. Your comments have told me what I needed to know, and I appreciate your experience with this horn. Take care, and God Bless!

Every Good Wish,
Doc

[Doc Mark]

Greetings, Friends,

Does anyone have a good recipe for crow??!! After thinking about this for a bit, and after the seller lowered his BIN price, I decided to go ahead and jump on the JBL Smith horns, plus their proper adaptors, that he was offering! SOOOO, tonight, I shall cook up a nice dish of boiled crow, and shall make myself eat every last bite, for being so sure that I would not be happy with the horns that I have just bought!! :o::blink::o:;):bouncy:

Thanks to Mr. Widget, Jerry_Rigged, and others, who jumped in to answer my questions about these horns. In truth, I had been saving some coin for a new pistol, but what the heck, eh??!! I'll let you know how the Smiths are, when they arrive here. Take care, and God Bless!

Every Good Wish,
Doc (still learning not to be so sure of his likes and dislikes.....!);):D

[Doc Mark]

Howdy, Friends,

Well, my "new" JBL 2397 Smith horns, with their proper adaptors, arrived today, safe and sound. Overall, I'm fairly satisfied. However, I must admit that the seller DID misrepresent the condition of these horns. In the photos he posted, it appeared to me as if one of the horns had been dropped on its front lips, and I asked him about that. He got huffy, and replied, in a fairly indignant tone, that the thing I thought I saw was nothing more than a paint problem, and that there were no depressions on the front lips. Truth be told, he lied, pure and simple! One look is all it took to verify that what I thought had happened, had happened, indeed! One horn does have a concussion mark on both horn hips. No, it's not really bad, but you can easily see that tiny fractures radiate backwards from the initial point of impact. Also, both horns have had extra screws added, as they seemed to have had a small problem in stability, probably caused by the fall they endured. One horn also needs some filling, sanding, and painting where those fractures are. Would I buy them again, for the price I paid, had the seller been more honest with me? Very probably not. But, now that I actually have the horns in hand, I see that, with a little work on my part, they will be look very nice, should function as new, and will be very satisfactory. I'm just disappointed that the seller deliberately lied to me about an honest question asked about his offering. I'm not sure if I can give him a positive feedback, or not. Though I can "make do" with his offering, and I am, overall, happy about how they will eventually turn out, I do not believe his dishonesty deserves a positive feedback. Am I wrong about that, Friends, being happy with the horns, themselves? I'd love to hear what you all think, if you would be so kind as to share your thoughts on all this.

I'll also take and post photos soon, so you can see the damage for yourselves. One note, all JBL logo stickers are in place, and in fairly nice shape, so that's a good thing! Thanks, very much, and God Bless!

Every Good Wish,
Doc

[cooky1257]

Hey Doc, I hope you like them-I really enjoy mine for sure.
They are only mdf and are easily damaged though they are an easy restore if its just surface dings-I used car body filler on mine and mdf is like caster sugar to sand, it's an easy job. The battleship grey was a problem to me so I masked off the decals and sprayed them stove black. Enjoy.
Cooky

[Doc Mark]

Hey, Cooky,

Many thanks! I'm looking forward to hearing these guys, and think I may well like them quite a bit. I've got the 2397's, a pair of 2380A's, and a pair of 2311's (with 2308 lenses), all to try with my 2445J drivers. So, lots of fun stuff in store. I do think that the 2397's just might be the best of the lot, in many ways, however. Time and listening will tell the tale, eh?! How has the wide dispersion of this horn been in your listening room, Cooky? Any troubles? What's the soundstage like? Large sweet spot, or no? How do they sound working with the 2405/077's? Are your woofers a pair of 2235H's in each cabinet? Where do you have them all crossed over to one another? Thanks for any thoughts and impressions you may have about listening to these neat Smith horns. Take care, and God Bless!

Every Good Wish,
Doc

[cooky1257]

Hi Doc, well they don't image like a point source that's for sure;-) They have a huge sweet spot in my room-of modest UK proportions 5.5mx4.5mx2m well toed in 15-20 deg to help avoid any close first reflections. They sound excellent wherever you sit, either side of the listening sofa-it's all good. In a reflective sparsely furnished room they splash all over the place and hardly image at all-so 'well furnished' is a good place to start.
The sound is on the large side, instruments within the mix are BIG. I'm using the 2441@800hz with the 2405 coming in at 11.5k(XTA active xover). I tried the 2441 out to 14khz recently, the system as a 2 way, and think I may prefer it-the imaging is certainly more focused.
Yep they are reconed 2231's to 2235's. My summer project is some cnc'd h9800's via my University workshops with 2435hpl's all mated to the dual 2235's again actively eq'd via the XTA.
Cooky

[Mr. Widget]

Hi Doc, well they don't image like a point source that's for sure;-)

The sound is on the large side, instruments within the mix are BIG.:yes:

I would add the sound is also slightly forward... like most JBL systems.



My summer project is some cnc'd h9800's via my University workshops with 2435hpl's all mated to the dual 2235's again actively eq'd via the XTA.I'll be interested in what you think of the comparison. I made a similar journey a few years back. Personally, I preferred the 2397 sound. The really big sound stage and natural sound quality.


Widget

[cooky1257]

Hi Widget,
On the h9800/2345 front I'm looking forward to finding out.
Could you shed any more light your own conclusions?(I must've read every 435/horn related thread on here) but I'd be interested in a quick recap if you have the time.
Cooky

[Mr. Widget]

I must've read every 435/horn related thread on here, but I'd be interested in a quick recap if you have the time.I can't give you a recap, but suffice it to say that I believe my view on the subject is likely in the minority. That said, I am not sure how many people who praise (or condemn) the H9800/435Be combo or the K2-S9800 have actually had them in their own homes and really gave them a long listen.

As for my subjective view, the H9800 with 435Be on it compared to the 2397/2441 is a lot like the difference between playing an analog record and playing the CD of the same music. In that analogy, some people prefer one over the other, but more specifically the H9800 combo is more center focused with a significantly shallower sense of stage depth than the 2397 combo.

For some people these attributes of CDs are insignificant for others, they are a big deal. For me they are important enough that while I much prefer the compact H9800 from a design standpoint, I really couldn't use it in my system.


Widget

[4313B]

And yet you seem to like the H4338 with the cheaper 435AL in the 1400 Array?

BTW, I suspect most people would prefer even the 4-inch 2452H-SL to the 3-inch 435AL, 435BE or 2435HPL.

[cooky1257]

while I much prefer the compact H9800 from a design standpoint, I really couldn't use it in my system.


Widget

Thank you, this summer's adventure should be interesting.
I'll hold off on selling on the 2397/2441 combo till I'm absolutely certain it's right for me.
Cooky

[Doc Mark]

Evening, Cooky,

Are you considering selling off your 2397/2441 combo, in an effort to search for that elusive "perfect" system? Best of luck, no matter how it turns out for you! Take care, and God Bless!

Every Good Wish,
Doc

[Mr. Widget]

And yet you seem to like the H4338 with the cheaper 435AL in the 1400 Array?I do like them... though I have only had a few rather brief listening sessions. I hope to have access to the SAM version in the not too distant future... I'll know them better then. I expect I'll continue enjoying them for a high end HT system... I am not sure how I'll feel about them for two-channel.

The short comings of the H9800/435Be as I see them may not be a problem at all in a 5.1 or 7.1 system. When you add surround processing and a center channel, the criteria for a successful design are not the same as those required for a superb two channel stereo system.


Widget

[cooky1257]

Are you considering selling off your 2397/2441 combo, in an effort to search for that elusive "perfect" system? Best of luck,

No, the combo is an excellent fall back position, I was merely saying I'll not be too hasty!
Cooky

[DAS]

Hello, I'm trying to find out what the "recommended cylindrical baffle" is...I have a pair of 2397's with adapters and 2425 drivers mounted in cases...sort of works like baffle but surely not correct...and I have another pair with 2445's which I'd like mount in cases, and get the baffles correct...using these for small PA systems and they sound sooooo smooth...help please!

Thanks!

[10 Watt Street]

The recommended cylindrical baffle extends 3" above and below the mouth. I believe that is tied to the 60 degree vertical beamwidth spec:
http://www.lansingheritage.org/html/jbl/specs/pro-comp/2397.htm

They employed it in the Cinetron system:
http://audioheritage.csdco.com/vbulletin/showthread.php?p=111188&highlight=cinetron#post111188

[pos]

I would take those early plots of mine with a grain of salt... these were some of my very first measurements and I wouldn't be at all surprised if they were not entirely repeatable. ;)

I found some more recent measurements by Widget (2005)
http://www.audioheritage.org/vbulletin/showpost.php?p=58582&postcount=32
http://www.audioheritage.org/vbulletin/showpost.php?p=58663&postcount=36

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=8265&stc=1&d=1118185174

[pos]

and here is an interesting post with measurements of 2435 on westlake smith horn with a P-Audio adapter.

It looks really good! (measuring conditions unknown...)

http://www.audioheritage.org/vbulletin/showpost.php?p=247214&postcount=85

Cooky, are you starting to regret your 2397? ;)


I tried the 2397 with 2470, LE85 and 2435.
The LE85 was already way better than the 2470, but the 2435 is really a huge step forward in my opinion. My H9800 clones are now on the shelf (for some time at least...)

I am using the same P-Audio adapter:
http://www.audioheritage.org/vbulletin/showthread.php?p=259601

[cooky1257]

Cooky, are you starting to regret your 2397? ;)



:)No, I never tried the 2435 on the Smith but what they and the SAM1HF have in common is they don't sound like horns.
The 2397 very wide dispersion is a major issue for my circumstances however and in this the SAM nails it. Isn't there an issue with the 2397 that it starts to beam narrowly above about 11k so precludes its use as a 2 way?
The 2397's are off to their new Belgian owner once the funds have cleared as are the 2441's.
Cooky

[Mr. Widget]

:)The 2397's are off to their new Belgian owner once the funds have cleared as are the 2441's.I wouldn't have decided to send them off quite so quickly... while I tend to agree with the direction you've headed I would have thought a series of proper comparisons would have been good.

While I never did sell off my 2397s or the first pair of Westlake clones I built that were pictured here years ago, I haven't played either of them since sometime in late 2004.



I tried the 2397 with 2470, LE85 and 2435.
The LE85 was already way better than the 2470, but the 2435 is really a huge step forward in my opinion. My H9800 clones are now on the shelf (for some time at least...)You should try the 2441 or better still, the TAD TD-4001. Unfortunately the TD-4001s are quite pricy... even if you pick up some blown drivers the diaphragms are $1500 ea. :biting:

A note about the 2397 plot of mine posted above... if you read the notes at the bottom of the plot you'll notice that both curves are of the 2397 with a TAD TD-4001. One is using the standard 2328 throat adapter and the other a custom made adapter. Had I used a JBL 2441, the curves would have been fairly similar but slightly less extended and less linear.


Widget

[cooky1257]

I hear ya,
Well the 2441/2397/2405 combo did me proud during the time I had them.
The change to the (still not fully dialed in) SAM1HF's was revelatory in terms of detail, precision and focus-an upgrade to the extent I feel I have a new cd collection, stereo image is very good in my listening room they project a wide stage into the room with good image depth.
It wasn't all one way however like most things in life it ain't all win win. The vintage combo had a presence, dynamics and scale that was extraordinary if ultimately false but oh so impressive and great fun, the stereo image was huge though a bit of a mess as if every instrument was competing to be huger than the next. Had I the luxury of finance and space I may have kept them for some future fun but to these ears the newer stuff is well worth investigating. To satisfy any 70's nostalgia cravings I just picked up some 4311's for the back room system.
Cooky

[Dr.db]

Here is a comparison between the JBL 2397 and one of my Westlake clones. It is interesting how the the wider lips of the Westlake do seem to improve the lower response, but at a sacrifice at the top end. This explains why I always feel the need to EQ up a bit around 6-10KHz.



I know it´s been a long time since...

But I have one question; did the Westlake clones use the 2328 throat-adapter as well ?
Could this cause the difference at the top end ?
If the Westlake clones didn´t use this adapter, I guess their inner height was bigger? Probably 2" height for the westlake and 1,5" height for the 2397....!?

[ivica]

I know it´s been a long time since... But I have one question; did the Westlake clones use the 2328 throat-adapter as well ? Could this cause the difference at the top end ? If the Westlake clones didn´t use this adapter, I guess their inner height was bigger? Probably 2" height for the westlake and 1,5" height for the 2397....!?


Hi Dr.db,

I would expect driver to horn adapter something like on the figure
or 2" horn height as explained in the:
http://www.audioheritage.org/vbulletin/showthread.php?5425-Westlake-HF-Horns&p=49874&viewfull=1#post49874

regards
ivica

[Mr. Widget]

I know it´s been a long time since...

But I have one question; did the Westlake clones use the 2328 throat-adapter as well ?
Could this cause the difference at the top end ?
If the Westlake clones didn´t use this adapter, I guess their inner height was bigger? Probably 2" height for the westlake and 1,5" height for the 2397....!?Yes, the early Westlake horns that I copied did use the JBL 2328 adapter. I copied them exactly and also used the JBL adapter.


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[Dr.db]

Thanks a lot, both of you have been a big help :)

[Dr.db]

Are the later westlake horns without the 2328 throat adapter ?
Is their inner height 2" and what´s the advantages of these modifications?

[Mr. Widget]

Are the later westlake horns without the 2328 throat adapter ?
Is their inner height 2" and what´s the advantages of these modifications? The later ones are much simpler with a simple hole bored into a piece of aluminum… I'm not sure if this was better or just easier for them to make.


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[Dr.db]

So these would have a bigger inner height of 2 inch, right?


I`m just digging on this, because the crossover on the earlier modells were 1000hz and the newer modells have lower crossovers of 800hz :)

[Mr. Widget]

So these would have a bigger inner height of 2 inch, right?


I`m just digging on this, because the crossover on the earlier modells were 1000hz and the newer modells have lower crossovers of 800hz :)Depending on the document you look at JBL recommends different crossover frequencies for the 2397. In my opinion (based on measurements and listening) I prefer a 1200Hz crossover frequency for them and the original Westlake horns. I have no opinion on the later Westlake horns as I have no experience with them.

As a point of reference I feel the Altec 811B is best above 1200 Hz and the 511B is best above 800Hz. In my opinion, most of these horns get very "horn like" if used close to the specified low end crossover frequency.


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[Dr.db]

Thanks a lot for your instant help! :)
I`ll go with the 1200hz crossover then and stick to the approved design.

As the original Westlakes had less output in the upper frequency band than the JBL 2397, which diaphragm would you prefer for these horns?
The 2441 has extended highs but seems to gently rolls of from 6000hz.... is this really a smart match with the westlake horns?
The old style 2440 hasn`t extended highs, but has about 4-5db´s more efficiency from 6000-9000hz.
Do you think the 2440 would compensate the sacrifice in highs of the Westlake horns?

[Mr. Widget]

The best sound I ever heard from my Westlake clones or JBL 2397 horns was from the TAD TD-4001s. The difference between the 2397 and Westlake is measurable but not particularly audible.


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[Dr.db]

I just bought a pair of 2446 drivers and want to mount either new 2441 or 2440 diaphragms, which of these would you choose ?

[Richard Long]

Does anyone made curves with truextent Dia´s ? What´s the top end for the 2397 ?

[Maron Horonzakz]

Depends on the driver..

[pos]

... and the listening axis :p

[Lee in Montreal]

Does anyone made curves with truextent Dia´s ? What´s the top end for the 2397 ?

I think the limitation is not the driver or the diaphragm, but the combing effect which appears to hit at 10KHz

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=50773&stc=1&d=1301933450

[Richard Long]

Thx for the response.

i have the choice between 2441 and 2450.

I am interested in the difference of the curve with aluminium/truextent between 1.2khz to 10khz. at the moment i drive my 2441 with 2397 from 1.2 to 6.5 and after 6.5 i drive with a Fostex T925. next step is to change to truextent in the 2441, up to 10khz and over 10khz i will change to a Foste T500A MKII.

[ivica]

Thx for the response.

i have the choice between 2441 and 2450.

I am interested in the difference of the curve with aluminium/truextent between 1.2khz to 10khz. at the moment i drive my 2441 with 2397 from 1.2 to 6.5 and after 6.5 i drive with a Fostex T925. next step is to change to truextent in the 2441, up to 10khz and over 10khz i will change to a Foste T500A MKII.

Hi Richard Long,

Why to change 2441Aluminum diaphragm with anything, I would suggest You to change the 2397, with something like Yuichi A290 or A290S, like Tad TH4003.
I have seen a pair of A290S, seems the price OK

http://www.ebay.de/itm/DIY-YUICHI-A290-S-Horns-for-TAD-JBL-Fostex-BMS-Beyma-Radian-TOA-Altec-/111749822578?hash=item1a04cef872

regards
ivica

[Richard Long]

@ lee

thx for the curve, the red one looks quite good :)


@ ivica

i´m thinking about to change the horn but i have to do some tests ... and to buy some different horns :) - thx for the link!

[Flemming Skov]

I just bought a pair of 2446 drivers and want to mount either new 2441 or 2440 diaphragms, which of these would you choose ?

The 2446 diaphragms! I dare to ask, why would you change?

[Dr.db]

I´ve listened to the 2445 with titanium dia´s and didn`t like them as they tend to sound harsh...

I know the 2446 dia´s have ripple´s to stiffen the dia but they are still titanium.

[ivica]

I´ve listened to the 2445 with titanium dia´s and didn`t like them as they tend to sound harsh...

I know the 2446 dia´s have ripple´s to stiffen the dia but they are still titanium.

Hi Dr.db,

Any of them up to 10kHz, are relatively smooth, and FR response has 'bouncing' mainly influenced by the applied horn (length, shape, mouth "termination").
If you would to use it over 10kHz, then 2441 AL would be the best, then 2445 and the last 2446.I would not suggest Radian 1245 over 10kHz. SL and Be(Trex), may be can be used up to 14kHz. That are my personal experience, based on the higher resolution measurements, as You can see here on my the forum posts.
2446 diaphragm (ribbed) does not break too much up to 12-13kHz, but at the higher frequency its FR 'bouncing' is much larger the 2445 diaphragm (non-ribbed).

regards
ivica

[Ian Mackenzie]

I always mounted a 2405 slot under the bottom lip and it worked fine,

Without the 2405 it sounded muffled regardless of any EQ.

[Dr.db]

@ ivica: Have you had the chance to compare 2440 with 2441 diaphragm below 10khz ? Any advantage of the 2441 below 10khz ? Has it less distortion?

[ivica]

@ ivica: Have you had the chance to compare 2440 with 2441 diaphragm below 10khz ? Any advantage of the 2441 below 10khz ? Has it less distortion?

Hi Dr.db,

No, I have no opportunity to see, neither to measure 2440 driver.
Owing to it shape of aluminum suspension I would expect that it can
easily reproduce lower frequency mirage, but from the JBL data
2441 would easily reproduce sound even over 10kHz.
may be interesting:

http://www.diyaudio.com/forums/multi-way/157538-some-observations-regarding-jbl2440-2441-diaphragms-including-radian.html#post2028009


regards
ivica

[Dr.db]

Thanks for the link ;)