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bugust
03-05-2009, 09:46 PM
Hi All,
Glad to be a newbie, though familiar with alot of the cool JBL stuff!
I just beautifully scored for $100 a good condition pair of large speakers with the following combination of drivers:

LE 15 Woofer
PR 15 passive radiator
075 Horn
N2400 crossover.

Please help with identification.
Thanks,
Bruce.

Mr. Widget
03-05-2009, 10:07 PM
That is a very peculiar combination. The 075 and N2400 can be used together with an extended range woofer like the D130, and the LE15A and PR15 were designed to work together, but not with the N2400. Either someone has switched some parts on you or they had no idea what they were doing. Regardless of what anyone thinks of vintage systems... these components will not work out very satisfactorily. The 075 tweeter will be too hot and there will be a big dip in response between ~800Hz or so and ~2.5KHz.


Widget

bugust
03-05-2009, 10:12 PM
Thanks for the info. I read one of your previous posts and noticed that you said the LE 15 (not the LE 15A) is quite rare. The drivers in this are the LE 15, no "A" designation is present on the drivers...will this make a difference?

Mr. Widget
03-05-2009, 10:28 PM
The drivers in this are the LE 15, no "A" designation is present on the drivers...will this make a difference?Not in performance and probably not in resale value. If you intend to use these, realize the surrounds on the LE15s need to be treated or replaced as they are now stiffer than they were originally. For optimum performance they should probably be reconed, but that is not an inexpensive proposition.

FWIW: The LE15B is an entirely different beast and the LE15H is a newer generation LE15A with a ferrite motor.


Widget

bugust
03-05-2009, 10:45 PM
the boxes look factory, or is this unlikely?
ohm ratings:
LE 15 8 ohm
075 8 ohm

...by the way - my huge mistake - they ARE LE15A, whew, can I just put my head in the sand now?

How would you suggest treating the surrounds?

Mr. Widget
03-05-2009, 11:24 PM
the boxes look factory, or is this unlikely?
ohm ratings:
LE 15 8 ohm
075 8 ohm

...by the way - my huge mistake - they ARE LE15A, whew, can I just put my head in the sand now?

How would you suggest treating the surrounds?8 ohms is only useful in approximately dating these things... all LE15As are the same impedance as are all 075s... some say 8 and others 16. 8 ohms means they are from the '70s.

Look for your cabinets and other info here: http://www.lansingheritage.org/html/jbl/catalogs/jbl-catl.htm

As for treating the surrounds, I don't recommend it unless you have a very steady hand and know how to measure the woofer's Fs. Do a search for DOT 3 on this site. You will find several threads.


Widget

subwoof
03-06-2009, 07:38 AM
Yet again, a picture is worth a thousand words. factory could mean anything.

bugust
03-06-2009, 01:01 PM
So I have this frankenstein system in a big 8+ cubic foot sealed box. Would it be a further obscenity to mount in a spacer and put a D123 in where the LE15A was being used? Will this close my crossover gap? Will the passive radiator still be ok for this application?

bugust
03-06-2009, 01:30 PM
I actually have a choice. I have a pair of D123s and a pair of 123a-1s. Which would go better in a big box with a 15" passive radiator and a n2400/075 top end?

Lawrence HF
03-06-2009, 01:57 PM
Is it possible that a LE85 or 375 is present that you did not "see".

Mr. Widget
03-06-2009, 02:03 PM
So I have this frankenstein system in a big 8+ cubic foot sealed box. Would it be a further obscenity to mount in a spacer and put a D123 in where the LE15A was being used?Yes it would.

I don't suppose you are related to the original owner?


Widget

bugust
03-06-2009, 02:07 PM
OK. Define Obscenity.

Mr. Widget
03-06-2009, 02:11 PM
OK. Define Obscenity.I know it when I hear it. ;)


Widget

Titanium Dome
03-06-2009, 08:46 PM
OK. Define Obscenity.

It's your word choice, so you probably should define it, but I'll give it a swing.

Let's say your speaker walks into a party in its underwear, everyone looks at it and points, a few ladies cover their eyes or turn away, and your speaker yells, "What the h#!! are you looking at?"

In scene two, your speaker shows up at a party completely naked, everyone looks shocked, women scream and faint, men curse and tell it to leave, and it shouts out, "Just what the f@#k are you looking at!?!"

The second would be a "further obscenity" both in action and language.

Now, Bruce, I'm only funnin" you a bit. You got a great deal just on the components alone, and you have the foundation of a nice system, especially if you do a little horse trading for things that you need in exchange for things that you don't.

You should check the archives, the library, and search old posts to see the combos that really shine, then aim to recreate those combos.

Here's an example of what you can find:

http://www.lansingheritage.org/html/jbl/catalogs/1974-home.htm

Good hunting.