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D@VID
09-08-2003, 12:38 PM
A friend of mine got a ("very") second hand JBL L40 pair of speakers (despite my warning). One of the speaker terminals were broken so the speaker got to be opened... And then came (his) surprise (and explanation of the low price!). The Crossovers are all messed up (read: some kind of bad DIY work), on both speakers!
Now we need the schematic of the original crossover for this speaker so that we can "build" a "original" x-over.
Can somebody, please, help?

Best regards,
David.

P.S.
I'm new to this forum and this is my first post. But, i already enjoy it! Cheers!

4313B
09-08-2003, 01:14 PM
Here it is :)

D@VID
09-08-2003, 01:32 PM
WOW!!!
I am speechless... That was fast (&furious)!
Thank you very, very much Giskard!!!

Is there any recommendation/comment regarding the xover components and perhaps inner cabling?

Thanx again!
Best regards,
David.

4313B
09-08-2003, 01:38 PM
You're welcome. We aim to please, or at least to cause the least amount of collateral damage :p

Since the introduction of the JBL Ti series I've wired inside the enclosures with Monster Cable.

D@VID
09-08-2003, 01:45 PM
I am very pleased and happy especially since no collateral damage is done!:D :D :D

I've got some Monster XP speaker cable... I guess that will do.

You guys are awesome!

Cheers!;)

D@VID
09-11-2003, 02:08 AM
Hello again, Giskard!

I'm sorry to bother you again, but there's been a missunderstanding or to be more precise i didn't give you the right info. I didn't know that there are 2 (even more?) versions of the JBL L40! So i need the schematic for the (european) version of the L40 (three way speaker, no tweeter attenuation, around year 1995 model). Here's what the catalogue says (if that will help):

Drive unit complement:
- Woofer: 708G. 200mm driver with 50mm edgewound voice coil
- Midrange: 704G. 130mm polypropylene driver with 25mm voice coil
- Tweeter: 050Ti-1. 25mmtitanium dome with integral diamond surround

Crossover Frequencies:
- 350Hz/2.5kHz

Dimensions, mm (HxWxD):
- 650x300x330

Cheers,
David.

Robh3606
09-11-2003, 09:09 AM
Well this is the closest I could find. It should at least point you in the right direction. 2 of the 3 drivers match and the crossover points are close. Good Luck


Rob:)

Don McRitchie
09-11-2003, 08:27 PM
I believe this is what you are looking for:

4313B
09-11-2003, 08:54 PM
Did you get this sent to you from Service?
What was the original pdf name?

Don McRitchie
09-11-2003, 09:17 PM
I ripped it off the Harman Consumer site during the brief time that the tech sheet directory had public access. It was in a subdirectory called "International". I pulled off a copy of every file there. The file in question is named L40ts.pdf.

D@VID
09-11-2003, 11:25 PM
Hello Don,
Thank you very, very much!!!
By the way: this is a very informative and helpfull forum. And interesting too!
This world would be a much poorer (have i written it right?) place without you!
May you have happy listening sessions.

Thanx!!!

Best regards,
David.

4313B
09-12-2003, 04:37 AM
Ah! We no longer have access to the "International" stuff and I didn't bother to pull that directory off when the site was unsecured :p

D@VID
09-13-2003, 06:24 AM
Luckily someone did!:D

Cheers!;)

GordonW
09-13-2003, 09:28 AM
Isn't there an L40T3 in the US, that's basically the same thing as this? I ask, as I think I KNOW someone who has a pair of these...

Regards,
Gordon.

4313B
09-13-2003, 10:24 AM
Originally posted by GordonW
Isn't there an L40T3 in the US, that's basically the same thing as this? I ask, as I think I KNOW someone who has a pair of these...

Regards,
Gordon.
Yes there is an L40t3 in the U.S.
Here's the schematic to that model

GordonW
09-13-2003, 10:20 PM
Ah, OK, that's right... the L40T3 is only a 2-way, but with the 8" woofer.

Go figure, they're using the same basic model number for not TWO, but THREE different driver combinations over the years! :spin:

Regards,
Gordon.

spkrman57
01-12-2006, 08:45 AM
I am in the process of obtaining a pair of L40t3's and looked at the crossover for the L40t3 and looked at the crossover for the L80t3 and found the crossover similiar except for the coils.

L80t3 has 4 ufd cap and 2 mh coil

L40t3 has 4 ufd cap and .5 mh coil

(bypass caps .01 ufd are not mentioned as they have no part in my question)

Other than different attenuation resistors is the different coil in the crossover responsible for the crossover frequencies being so different from each other?

L40t3 is 2.5khz
L80t3 is 4.5khz

Can I have some comments/recommendations, I plan on using the 035Tia and LE14H-1 along with 5" mid for 3-way system similiar to the 240Ti!

Ron

Earl K
01-12-2006, 10:35 AM
Hi Ron,


Can I have some comments/recommendations, I plan on using the 035Tia and LE14H-1 along with 5" mid for 3-way system similiar to the 240Ti!

- Yes,,,
If cobbling together a 3-way using the le14h-1, 104h-2 & 035ti compontents , I would blend together the NL240Ti & NL80t3 networks. This would be my starting point before real-world tweeking. ( The NL240Ti would contribute its' woofer section of the blended network / with the NL80t3 providing the midrange & tweeter sections. )



I am in the process of obtaining a pair of L40t3's and looked at the crossover for the L40t3 and looked at the crossover for the L80t3 and found the crossover similiar except for the coils.

L80t3 has 4 ufd cap and 2 mh coil

L40t3 has 4 ufd cap and .5 mh coil

(bypass caps .01 ufd are not mentioned as they have no part in my question)

- Okay but I think you are quoting the wrong mH values for the coils found in the networks' tweeter section .


Other than different attenuation resistors is the different coil in the crossover responsible for the crossover frequencies being so different from each other?
FWIW;
- I read the tweeter coil ( in the NL80t3 ) as a .2 mH value / not 2 mH . A .2mH value makes electrical sense.
- These tweeter coil values ( .5mH & .2mH ) combined with the different fixed pad values will net the different crossover points that you mention ( as compared between the L40t3 & the L80t3 ).

:)

PS ; I would also include that nifty 3 position "pad" switches ( along with the extra resistors ) that are found in the 240Ti. I would also DC bias all the series caps in the networks .

EDIT It occurs to me that my comments to your query may be better placed over in the new "DIY" forum.

spkrman57
01-12-2006, 11:20 AM
Yes Earl, That would make sense, I just happened to be looking for the L40t3 crossover an posted without thinking.

My bad, can someone move my posts to the proper location?

Thanks, Ron:banghead:

artsound
06-12-2006, 01:16 AM
Hi all,

I got a pair of LE14A 16Ohms and Altec 808A+811 horn.

Do you have any schematic of crossover for LE14A and LE175. Cuz LE175 and 808 could be the same config?

And about data sheet of LE14A, in brochure, we can't get any data such as Qts or Eff... Do you know somewhere we can get it?

Thanks,

Phil H
06-12-2006, 09:47 AM
A bit different than the original thread about an L40, Anyway

At the bottom of the forum is a Links catergory(http://audioheritage.org/vbulletin/forumdisplay.php?f=60). In the consumer section there is a link to the tech sheet for the L101 that uses those drivers. In the professional section, the Thiele Small Parameters link has the LE14A listed. The Network Schematics link also has the LX10 used in the S1.

I hope this helps. I know very little about the DIY stuff. Others can probably give you better advice and perhaps some thoughts on a more modern network and the Altec driver.

Earl K
06-12-2006, 01:59 PM
Hi


I got a pair of LE14A 16Ohms and Altec 808A+811 horn.

- Those le14a(s) are most likely 8 ohm . Put a DMM ( Digital Multimeter ) on them and measure their DCR ( dc resistance ). Then let us know the reading .


Cuz LE175 and 808 could be the same config?

- Choose a network that primarily complements your choosen horn/driver combo / then modify it to accomodate the change in woofers .
- IME ,,, when using a full sized exponential/radial horn - one shouldn't use a network that was designed around a JBL compression driver working into 2301/5 type lense. For example; the LX10 has a 2-pole "bump filter" that gives boost ( gain ) in the 1500 hz region ( to compensate for the anemic midrange response of that DLH175 combo in that FR area . ) The 811/808 does not need boosting in this area / it needs some attenuation. Also , the LX10 lacks a low-pass network section for the woofer. Some may see this as a plus / maybe / but running the woofer flat-out presents another complication to smoothing the upper end response of the le14a .


And about data sheet of LE14A, in brochure, we can't get any data such as Qts or Eff... Do you know somewhere we can get it?

- Phil has pointed the way to some stats.
- To marry the Altec 811/808 combo with the JBL le14a means you're mating a horn device that's around 107 db efficient to a woofer that's approx. 92.5 db efficient . IMO, you need a network that includes fixed padding working with variable padding in the horn circuit ( the LX10 did have that going for it ) / along with a bit of HF compensation ( if you are running without a tweeter ) .
- The closest "stock" network I can think of is the N1201 from the Altec Model 19 . I'd like to see this network modified somewhat / unfortunately / I don't have the time to take on that task . Maybe someone else will take an interest in this coupling .

:)

artsound
06-12-2006, 08:01 PM
Thanks Earl K and Phil,

You're givin me so much helpful information. I'll build LX10 first then N1201. But LX10 just cut in 1500Hz, and my point is 800Hz, means we need a bigger caps than 12uF in circuit??? Could be 20uF, how do you think? And inductor, air gap is better, I think. 0.9mH => Height: 0.34in; Radius: 0.68in; turn: 135; Wire Dia: 0.021in; Power: 75W.

About DCR of LE14A, I'll check again t'nite. Cuz those're a pair of little bit heavy enclosure.

You'll get the result soon.

artsound
06-13-2006, 07:34 PM
You're rite Earl. DCR: 6.7 and 6.8 Ohms.

Bones
04-03-2011, 09:57 PM
Weird
I searched for "L40" in the Forum Search engine and I get the following message:
vBulletin Message

Sorry - no matches. Please try some different terms.

So then I do a Google search and it took me to this thread on this forum. I think my trust in the search engine on this forum has just evaporated (note - I did the search while logged into the forum - Doh!
Any ideas as to what's up?

4313B
04-04-2011, 05:06 AM
Any ideas as to what's up?The forum search has been broken forever. I always use Google to find anything.