Thoughts on the JBL 2395 slant plate lens ?

[doucanoe]

I've been a long time sucker for horns. Sucker, meaning my fascination of different designs and design philosophies, leads me to want to try them all in DIY projects. While many have been successful endeavours, some have turned out to be a swing and a miss.

A couple of days ago I decided to pick up a pair of JBL 2395's that were available locally. These as you know, are probably too big for their own good but the "sucker" in me won out and I grabbed them ;)

I was wondering if anyone would like to share their experiences with them used in a home audio application. What worked well, what didn't etc.

Also, tips or suggestions from any members have taken the time to dissassemble them for refinishing. I haven't had the time yet to determine how the plates and spacers work together so I'm reluctant to just start off unbolting things.

Thanks
RC

[jcrobso]

http://www.jblpro.com/pub/obsolete/acoustic_lens_family1.pdf
I have the 2391 and the sound very good. But the 2395 is whole different class, yes they are BIG! Post some photos when you have a chance!

[badman]

http://www.jblpro.com/pub/obsolete/acoustic_lens_family1.pdf
I have the 2391 and the sound very good. But the 2395 is whole different class, yes they are BIG! Post some photos when you have a chance!

Not surprising since it exhibits much less beamwidth tapering.

[doucanoe]

Well, here are some pics of one of them anyway.

Please forgive the frilly, non-audio guy table lamp cover. I needed some place large enough to set one of these on for pics and my wifes sewing table was available. This table has been deemed off limits for audio gear but she's upstairs at the moment so... no see, no foul ;)

They need a little tune up but are in pretty nice condition overall.

RC

[SMKSoundPro]

What drivers will you bolt on to these?

[scott fitlin]

Do you have the front mounting legs, and the H brackets?

[doucanoe]

What drivers will you bolt on to these?

I have 2441's but am currently using them in my main system and I don't see that changing. That leaves me with my EV DH1A's. They are only other pair of 2" compression drivers I have at the moment.

RC

[doucanoe]

Do you have the front mounting legs, and the H brackets?


I have been speaking with LG about a pair of H brackets he has available but I'm not familiar with what the front mounting legs are.

Are these needed and what did they do exactly? I can see where the brackets would come in handy but if this is to be free standing, do the legs do something other than elevate?

RC

[scott fitlin]

They are supposed to have mounting legs on the front at the bottom of the 1st slant plate. You will see screw holes on the bottom of the rectangular frame the slant plates attach to and they legs hold the lens up OFF the cabinet they are on, and facilitate secure mounting as well.

[doucanoe]

They are supposed to have mounting legs on the front at the bottom of the 1st slant plate. You will see screw holes on the bottom of the rectangular frame the slant plates attach to and they legs hold the lens up OFF the cabinet they are on, and facilitate secure mounting as well.


Thanks Scott.


Hmm, I'm not seeing any screw holes, assuming that I am looking in the right place at least. I'll have to give them a better look later.

I guess a guy could fabricate something to accomplish the same. Thats something that happens around here quite a bit ;)

RC

[doucanoe]

Anything on this page look like what we are talking about here?


RC

[doucanoe]

The JBL literature states " The JBL 2395 is a slant-plate acoustic lens for use above 800Hz". Does that mean that that this horn and lens will do well down to 800 or should it really be crossed over much higher?

I realize that I would not get ideal HF used in a two -way regardless of x-over point with the EV DH1A but am wondering if crossing over around 1200 would make more sense. I'm not sure where people have has good results for use in a home audio application.

Please keep in mind that I'm just horsing around with these at this point. I just want to get a feel for what this horn/lens sounds like but still want to give it a fair shake at the same time.

RC

[louped garouv]

The JBL literature states " The JBL 2395 is a slant-plate acoustic lens for use above 800Hz". Does that mean that that this horn and lens will do well down to 800 or should it really be crossed over much higher?

I realize that I would not get ideal HF used in a two -way regardless of x-over point with the EV DH1A but am wondering if crossing over around 1200 would make more sense. I'm not sure where people have has good results for use in a home audio application.

Please keep in mind that I'm just horsing around with these at this point. I just want to get a feel for what this horn/lens sounds like but still want to give it a fair shake at the same time.

RC

Historically; in the nightclubs at least....
(and in my basement too)
it was/is common to cross them somewhere near 800Hz with 18db slopes;


i also had more than satisfactory results crossing them at 1200Hz with 12db slopes

[scott fitlin]

We always used 800hz as the xover point, and later on in the 80,s we changed to 750hz at the suggestion of Lew Feldman, a sound designer, using the Richard Long gear, set up and concepts. We use the JBL 2441J on our lenses and I have tried other drivers, and also own some other drivers. Crossover frequency is NOT carved in stone, though, I find 750hz 18db or 12db butterworth sounds great with the 2441, but a slightly higher 800hz frequency sounds better with my TAD 4002 drivers. So, I think it depends on what driver you use, and what, through experimenting, sounds best to you. I also roll them off where the tweeter comes in, and it is said the lens is not good above 10k anyway.

What will the rest of your system be comprised of that the 2395 will be part of?

[doucanoe]

Historically; in the nightclubs at least....
(and in my basement too)
it was/is common to cross them somewhere near 800Hz with 18db slopes;


i also had more than satisfactory results crossing them at 1200Hz with 12db slopes



Hey LG, I have a pair of Altec N801-8A networks kicking around here somewhere to play around with but those are 2nd order top and bottom. Maybe I'll have to build something.

RC

[louped garouv]

Doucanoe, the post with the H brackets does not show the front mounting legs. But these can be made by ANY metal machine shop. They are simple small steel bars with 2 short sharp bends.


kinda like the brackets on the bottom of the baffle board in the MA25 set?

[scott fitlin]

kinda like the brackets on the bottom of the baffle board in the MA25 set?YEAH, THATS THEM, attached to the rectangular frame the slant plates are attached to!

They can be made by a metal machine shop, and will not cost you much.

Thanks, Dave, I missed them completely! :dont-know:

[louped garouv]

Hey LG, I have a pair of Altec N801-8A networks kicking around here somewhere to play around with but those are 2nd order top and bottom. Maybe I'll have to build something.

RC

you may be OK...

i have some passive yamaha DN-2800 8K units if you want to play around with a tweeter too...
(and don't have the appropriate filters already)

[louped garouv]

YEAH, THATS THEM, attached to the rectangular frame the slant plates are attached to!

They can be made by a metal machine shop, and will not cost you much.

Thanks, Dave, I missed them completely! :dont-know:

no worries Scott...

hope the boardwalk is rocking this summer!

[scott fitlin]

Hey LG, I have a pair of Altec N801-8A networks kicking around here somewhere to play around with but those are 2nd order top and bottom. Maybe I'll have to build something.

RCI kinda like 2nd order xover on these horns myself! You gotta try 2nd and 3rd order filters and see what they sound like and then you can decide.

I will tell you this, one time, when I had a BSS 366t in my system, I made a mistake programming my unit, and accidentally set the horns filters to to 1st order, 6db slopes! And I ran the system this way for a few days till I caught my mistake, BUT WOW, IT DID SOUND VERY VERY GOOD!

Something I am fond of is 2nd order Butterworth filters on my 15,s and horns, and 3rd order Butterworth on the tweeter., :D

[doucanoe]

I figured that it was what was shown for the MA25 kit but the frame shown threw me off a bit.

10K max, eh.

Other than the inductors, I think I have enough to breadboard a 2nd order Butterworth for woofer and horn. I'll have to give the tweeter some more thought but certainly could go 3rd order on the tweeter for 3-way.

Where would you bring the tweeter in at if a guy were to go that route?

What I have on hand right now that isn't built into something would be a pair of E145's and Gauss 4583F's for woofers and a pair of Fostex T90A's or Yamaha JA4281B's for HF.

The bass cabs would probably end up being a not so pretty pair of Caberet that are close to the internal volume of the JBL 4507's.

With those cabs, it wouldn't end up being a "for show" set up but get me started anyway. My basement looks like a war zone anyway so they should fit in nicely with the decor in my audio area down there ;)

RC

[scott fitlin]

Well it depends on the tweeter. Right now I am at 7k between the 2395/2441 and the 2404 bi-radial.

I am installing some brand new TAD ET-703 tweeters, they should arrive here next week. I, at the recommendation of others, including Mr. Widget whom I bought these from and he also uses them, will change to 8k when I install the 703,s!

So, depending on what tweeter you use.

[doucanoe]

Thanks guys! Great info. for me to work with now :)


RC

[Lee in Montreal]

The thread is 18 months old, but I think that I can contribute by presenting how to make the front stands and spending only a few bucks. That solution was inspired by Shorty on his DJ rig. The stands are 6" wide and 4.5" tall. I will sand them and paint them a dull black when I have time. The front stand are very sturdy.

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0968.jpg

[doucanoe]

That looks like a pretty slick way of handling it, Lee. If and when I get back to horsing around with mine, I'll steal that idea and run with it myself :)


So far, I built crossovers based in the of the suggestions presented and have played around with them running with 4507 cabs with E145's. If it goes any further, I will probably run them with my 4560's or build something.

I was messing around in Sketchup a while back and came up with this. Dim's are close but that wasn't the focus. I just wanted to get a visual representation of what was bouncing around in my melon ;)

[Akira]

One thing that people forget is the "era" gear sounds and works best with "era" components. The iconic Klipshorn (forget the model) that sat in the corner is a prime example of a speaker that never delivered it's potential using the latest high powered Brystons and Crowns but, came to life with a 25 watt 70's tube amp.

That said, I found the rather horrid 2482 phenolic driver an excellent match with the large slate plate lens. Something about that combination just works. The lens seemed to tame that overly powered driver making it sound like a speaker-- smooth. One thing that I do remember about the 2395 lens is how wide and even the coverage was--double width VS height. You can't duplicate that with a cone driver. So my guess is it would work well in a house. I have never used the setup in such small confines but, loved the results when combined with an additional radial horn handling the long throw coverage for P.A. I also started off my career in the early 70's disco era using them at the Ramada Inn clubs...the only job I showed up early to, so I could play these systems for my own pleasure and indulgence.

I have fond memories of the 2395...they seem to get romanticized in my memory as I age-- a bygone era.

[Lee in Montreal]

Greg Lake of "Emerson, Lake and Palmer" fame. I hope he wears earplugs...

2 x JBL 4520 + 2 x 2395 + 4 x 2345 + 1 x 2350

54516

[Eaulive]

Greg Lake of "Emerson, Lake and Palmer" fame. I hope he wears earplugs...

2 x JBL 4520 + 2 x 2395 + 4 x 2345 + 1 x 2350

54516.

Oh yes! That'll do it for me :applaud:

[louped garouv]

Greg Lake of "Emerson, Lake and Palmer" fame. I hope he wears earplugs...

2 x JBL 4520 + 2 x 2395 + 4 x 2345 + 1 x 2350



plus the wedge! ;)