Cool 2397 Smith horn set-up

[Steve Gonzales]

My Bud in N.Y. just picked up these original JBL 2397's with rare 2329 dual throat adapters. He is beginning the initial trial runs with the 2435 HPL Be. Vertec drivers installed with aftermarket repro 1.5 to 2" adapters. I thought you would get a kick out of seeing these. Enjoy:)

[Steve Gonzales]

more

[Steve Gonzales]

cool stuff.

[Alex Lancaster]

:) Awesome, pls lt Us know how it sounds.

[JBL Dog]

very cool!

:applaud: :applaud:

So, what kinda of do-it-yourself JBL project is it sitting on?

:hmm:

This message comes from JBL Dog :dj-party:

[Steve Gonzales]

I know that the enclosure(s) is a L200 with a 136a, a 2202(?), 2312/2420, 2405 originally. I'm not really sure about the midbass, I'll have to ask him again. Super cool guy, very humble about his stuff and quite a private person, I've tried to get him to join the LHS but he prefers to just do his own thing ,although he does admire the LHS site and monitors the Forum from time to time. He has owned MANY pairs of 4343's,4333's,4315,L200L300's and just about EVERY great JBL model both PRO and Consumer. He purchased some L250 crossovers and a UREI 525 electronic crossover and some sweet 300B tube amps so it is time to tinker to see what he can put together. He is responsible for my newfound love of compression drivers. He consulted me when I first tried to figure out the Summit horn swap into my L222's. I first installed the LE85's with HL87 1500hz horns attached and was VERY,VERY dissappointed. He said that I needed a longer horn and so I researched the conical horn info on the LHS and Jammin' Jersey site to find the correct 800hz horn and have NEVER looked back. I will fill in the blanks as the project progresses along for those with interest.

[Mr. Widget]

Those dual entry throats were meant to generate massive SPLs not audiophile nirvana, but what the hell... they do look cool. :applaud:


Widget

[paragon]

You never need this in your home !!
No, i doen´t want use this dual throat.
The phase ??

[Mr. Widget]

In my best Dr. Smith voice from Lost in Space, "Oh the phase, the phase!"


:applaud: :applaud: :applaud:


Widget

[Steve Gonzales]

Yeah, they have a lot of SPL potential for sure, but the same was said about my 2395/375's too and I find that they can play at normal levels just fine AND really knock your socks off when you turn it up. Neat toys. What do you think about a staggered crossover point? These amazing Be. drivers don't start to break-up until 15khz opposed to about 9-10k for Titanium. He is just exploring all the possibilities. Heck, you could almost live with using one for UHF duties right? Most people can't hear over 15khz anyways. Question: if the 2435HPL is rated at 117db @ 1w/1m, does the second one increase that to 120db 1w/1m? Is the consumer version using the same 3" Be. diaphragm? Hey Mr. Widget, did you buy some 076 lenses from Mike C.?

[Zilch]

JBL Tech Notes say don't do it.

[Except to make air raid sirens, etc., maybe....]

[Steve Gonzales]

That's funny Zilch! what the heck?, he's gonna tinker and see what it does. He is like one of us, if it doesn't sound good then he won't keep it that way. Ya can't blame a guy for trying right?;)

[paragon]

Nothing can beat the 2397 wood horn, believe me !! It´s the (prof) HiFi horn for your home !!:D

Eckhard

[Mr. Widget]

Most people can't hear over 15khz anyways.
I hope that's not true for most people.


Question: if the 2435HPL is rated at 117db @ 1w/1m, does the second one increase that to 120db 1w/1m?
Basically yes. It is also horn dependant.


Is the consumer version using the same 3" Be. diaphragm?
I believe they are different in the amount of Aquaplas, but I may be making that up.

Hey Mr. Widget, did you buy some 076 lenses from Mike C.?
Yes. I also ordered some proper diaphragms. As soon as I get the diaphragms I will compare them to my 077s.


Widget

[Steve Gonzales]

Thanks Mr.Widget for catagorically answering all my questions and I look forward to your comparison tests of the 076/077. thank you Paragon, he has been wanting the2397's for a long time. He originally bought some homebuilt wood horns that were simular to the 2397's but didn't really like them. Don't you have 2397's?

[paragon]

Yes, Steve, 2397 and 2390 i compared to them. I had the 2390 in the early 80`s and sold them for a pair of 2397. Now i paid the same price for them if they are new in the early 80`s:biting: . But the sound of them is bad compared to the 2397. If i get a pair of low price 2395 i will also compare them. But i think they will have no chance to beat the 2397 (use for HiFi !!).

Eckhard

[Steve Gonzales]

I don't believe the 2395 has enough vertical dispersion in a small enviroment to compare to the 2397's. I love how SMOOTH the 2397's are and they don't have such a small vertical sweet spot like the 2395's do

[paragon]

I love the 2395 and 2390 !! But i think the 2397 is the better choice !
Doen`t kill me !:D

Eckhard

[paragon]

The first hearing of the 2397 was : "Oh Good, what have you heared before ?".
Really !!

Eckhard

[Steve Gonzales]

I like the looks of the 2397 too and the dreamy-wide horizontal dispersion. My friend is also tinkering with how and what mounts to use and how high to place them. Any suggestions?

[paragon]

Your 220 are in your bedroom ? So you use the bass for other things ?:D
This is it ! Playing now in Radio. The 2397 are on top of my 4530 with a little angle down to the hearing position. That`s all.

Eckhard

[Steve Gonzales]

Hey, at 42, Ineed all the help I can get.They don't call them Disco's for nuthin';)
thanks for the info.

[Mr. Widget]

I like the 2397 right at ear level. I used them on top of the cabinets with no baffle and toe them in toward the listening position.

They do not sound good with the 2327 1" to 2" adapter. I have no idea about the 1.5" to 2" adapter, but my recommendation would be to use one 2" driver and the 2328 adapter.


Widget

[Steve Gonzales]

He will tinker with the present until he figures out what he likes. He does own a nice pair of 2445J's so, if it doesn't work out to his liking, he'll probably go with your suggestion of the 2328/2445J. thanks

[paragon]

Hey Steve, i need it more than you, cause i`m 47 !:D
I use a "boom" sub !

Eckhard

[johnaec]

I just got off the phone with Steve's bud in NY, (on another subject), and he said he plans to use these dual-throat 2397's as 2-way, with one driver handling the low portion and the other the highs. That ought to be interesting!

John

[Mr. Widget]

It may work out for him. Definitely an interesting experiment. I would expect there to be some severe cancellations as the two drivers' outputs mix in the throat. The response will certainly be a bit erratic.

I wonder what HF driver(s) he will try. None of the 1", 1.5", or 2" drivers really go "all the way up."

Widget

[lfh]

Neat experiment, indeed. It would be fun to bolt on a ring radiator with some kind of adapter and cross at say 12 kHz.

BTW, isn't there a German manufacturer that makes 2-way large format drivers?

[guest]

It may work out for him. Definitely an interesting experiment. I would expect there to be some severe cancellations as the two drivers' outputs mix in the throat. The response will certainly be a bit erratic.

I wonder what HF driver(s) he will try. None of the 1", 1.5", or 2" drivers really go "all the way up."

Widget

1-20k sounds like "all the way up" to me since the 2405 only goes to 21.5K Hmmm, maybe I did my homework.

http://www.jblpro.com/vertec1/vertec_manual/Vertec%20Chap%204A.pdf

http://www.jblpro.com/pub/components/2405.pdf

[johnaec]

I would expect there to be some severe cancellations as the two drivers' outputs mix in the throat. The response will certainly be a bit erratic.Why would you expect cancellations with two identical drivers? Assuming -3dB at crossover, wouldn't they just add normally? I really don't know - is there some phase issue?

John

[Mr. Widget]

Why would you expect cancellations with two identical drivers? Assuming -3dB at crossover, wouldn't they just add normally? I really don't know - is there some phase issue?

John


There will be some cancellations and peaking even in the situation you describe... i.e. using the forked throat as intended, but to use it as essentially a two-way, these issues will be exacerbated. At higher frequencies even slight variations in phase will cause the output to add and cancel more noticeably due to their short wave lengths.

Widget

[Mr. Widget]

1-20k sounds like "all the way up" to me since the 2405 only goes to 21.5K Hmmm, maybe I did my homework.


Not all specs are created equally. Due to the laws of physics, no one yet has made a 1" or larger compression driver that has a frequency response to 20KHz +/- 3 dB without external EQ.

Beyond that in all of my own personal experimenting even once you do add the necessary EQ, the quality of that UHF sound is not as good coming from a large compression driver as it is when produced by a dedicated UHF device. I am speaking in terms of ultra critical monitoring/playback... for PA use, hell yeah, turn up the EQ and let her rip.

Widget

[Mr. Widget]

BTW, isn't there a German manufacturer that makes 2-way large format drivers?


BMS 4590 http://www.bmspro.com/downloads/

[Zilch]

Not the "Siren" reference I'm looking for, but see pages 7-8 here:

http://www.jblpro.com/pub/technote/PD%20HF%20TechNote.pdf

{Wonders if "destructive interference" could be used to cook stuff....}

[lfh]

BMS 4590 http://www.bmspro.com/downloads/

Thanks for the link - I had forgotten the name of the company.