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LE15-Thumper
02-07-2004, 06:44 PM
I feel like a fool here. I have homemade L-300's I bought from a cousin. LX5 and N7000 crossovers. LE15H, LE85 and 2405 (pro 077) . I am not sure if my cousin had hooked up the xovers correctly. The woofer is connected to the LF of the LX5. The input to the N7000 connects to the HF of the LX5. The horn connects to the LF of the N7000 and the 2405 to the HF of the N7000. Is this correct ? What if I hooked the horn to the HF of the LX5 and then just hooked the input of N7000 to the main (amp) input at the LX5 and then connect the 2405 to HF of the N7000 as if adding a super tweeter ?
Which is the best way ?
Also, I have seen many posts about phase and running the mid out of phase. If I hook up the horn plus to plus and neg to neg would it be in phase or out ? Has JBL thought of this in advance or is it up to the user to reverse the leads to the mid ?
TIA

4313B
02-07-2004, 07:04 PM
Hello and welcome to the forum :)

LX5 and N7000 hookup

4313B
02-07-2004, 07:06 PM
LX5 schematic (http://www.jblproservice.com/pdf/Network%20Schematics/LX5.pdf)

N7000 schematic (http://www.jblproservice.com/pdf/Network%20Schematics/N7000.pdf)

hoto
08-05-2004, 12:29 PM
Hi

is the above connections apply to ALL JBLs set-up??

My home made 4343 have the following parts:

LE15a
2121
075
375/2309/2310
LX5
n7000
custom made 250HZ crossovwr (external) for the LE15A

my current connection are RED to RED, BLACK to Black which EXACTLY the same as the above connection, BUT, should I connect SOME with RED to BLACK to have the CORRECT set-up...Pls advise.

Thanks

Tom

boputnam
08-05-2004, 12:55 PM
Originally posted by LE15-Thumper
Has JBL thought of this in advance... :yes: Just "plug and play" - that is, follow the wiring scheme as on the schematics and the other diagrams Giskard posted here. Should be all good... I would not cross RED and BLACK unless you're inventing something...

Guido
08-05-2004, 02:15 PM
Hey Bo you were short this time :duck:

smartpolo
02-02-2006, 11:29 PM
:yes: Just "plug and play" - that is, follow the wiring scheme as on the schematics and the other diagrams Giskard posted here. Should be all good... I would not cross RED and BLACK unless you're inventing something...

I'd followed the connection as Giskard posted here, but I found the low is muddy. The woofers move inward when I connect the battery + to + and - to - terminals of crossover. I want to know if this connection method is still correct.

Anyway, I find it's much better when I connect the + output of xover to - input of woofer and - output of Xover to + input of woofer. Should I also need to inverse the polarities of MF and HF? :blink:

toddalin
02-03-2006, 09:06 AM
You have it correct and the woofer is supposed to move in on a positive signal. If you have a sound level meter, play tones in the crossover range and try chaning the horn wires between the terminals. Whichever way produces the louder signal is usually correct. Do same for horn to tweeter interface.

That said, it becomes apparent that when you adjust the horn, it has a profound effect on the tweeter. When I used N1200s and N7000s (and later N8000s), the horn was too "hot" even on the lowest setting, which of course made the tweeter very low. My solution was to wire it as shown and run the N1200 at full, but to put a 16 ohm L-pad across the horn letting me run the crossover full out (to the benefit of the tweeter) while reducing the horn.

I'm sure that many here will scoff at this, but the resulting sound was far and away superior superior ot the stock set-up.

4313B
02-03-2006, 10:17 AM
I'm sure that many here will scoff.I doubt it. A lot of those canned networks were pretty awful even back then so anything goes in the attempt to make them work how you want them to work. Neato cans though. If JBL has come anywhere in the past 60 years it's definitely in network design. For example, the latest network designs for the Array Series and the xxxxxxx xx are fantastic.

Zilch
02-03-2006, 10:46 AM
I'm sure that many here will scoff at this, but the resulting sound was far and away superior superior ot the stock set-up.Naw, L-Pads EVERYWHERE here; fixed resistors hanging on compression driver inputs, mostly.

I use adjustables for preliminary testing/evaluation only. Their impedances are rarely optimum.

The fundamental system voicing derives from the balance of levels between/among drivers. An RTA certainly facilitates getting it right, tho....

smartpolo
02-03-2006, 05:49 PM
I'd followed the connection as Giskard posted here, but I found the low is muddy. The woofers move inward when I connect the battery + to + and - to - terminals of crossover. I want to know if this connection method is still correct.

Anyway, I find it's much better when I connect the + output of xover to - input of woofer and - output of Xover to + input of woofer. Should I also need to inverse the polarities of MF and HF? :blink:

I have used the RTA to measure the phases; and I found all drivers are negative when all drivers are red to red and black to black. The woofers become positive when I cross the wiring. Now, I'm confused. Can someone tell me which connection is right?

4313B
02-03-2006, 05:51 PM
The connection that's right is the connection that sounds right. It's that simple.

smartpolo
02-03-2006, 06:32 PM
The connection that's right is the connection that sounds right. It's that simple.

But it seems to be abnormal compare with modern speaker when the woofer is reversed.

Zilch
02-03-2006, 06:40 PM
Try this: Reverse the midrange phase only from the standard wiring scheme above.

How does that sound?

I'll quote you the reference on that, if you'd like....

smartpolo
02-03-2006, 07:39 PM
Try this: Reverse the midrange phase only from the standard wiring scheme above.

How does that sound?

I'll quote you the reference on that, if you'd like....

Do you mean the woofer still keeps red to red and black to black? But, is it normal when the woofers move negative?

Zilch
02-03-2006, 08:30 PM
Do you mean the woofer still keeps red to red and black to black? But, is it normal when the woofers move negative?
Yes. Keep the woofer and tweeter in phase. Reverse the midrange only.

"The connections shown for the components of a three-way system will result in correct electrical phasing. If the component voice coils, however, are not in the same plane or arc, proper acoustical phasing should be determined experimentally,"

i.e., what Giskard said....

Most vintage JBL systems move negative. The sound reinforcement products have been changed to conform with contemporary AES standards.

Read and weep here:

http://www.jblpro.com/tech-library/JBL_TechNoteN1V12C_v5.pdf

majick47
02-04-2006, 08:24 AM
I experienced the same issue as LE15 Thumper with my L200b when I installed 3106 crossovers to run add on 2405 tweeters. The L pad for the LE85 horn was also controlling the output of the 2405 tweeter and I could barely hear it. As suggested I went with "what sounds right". I left the L200b crossover in its original wiring configuration to the LE85 and 136a, running the N200b power wires to the input of the 3106 crossover and I wired only the 2405 tweeter to the HF of the 3106. The resulting sound of the L200b speakers was a 100% improvement and I am able to adjust the LE85 and 2405 independent of each other. Now comparing the modified L200b to my L300 the L200b sounds very respectable. I know it's not by the book but by the book sounded awful and having limited technical ability this worked out very well for me.

toddalin
02-04-2006, 10:15 AM
I experienced the same issue as LE15 Thumper with my L200b when I installed 3106 crossovers to run add on 2405 tweeters. The L pad for the LE85 horn was also controlling the output of the 2405 tweeter and I could barely hear it. As suggested I went with "what sounds right". I left the L200b crossover in its original wiring configuration to the LE85 and 136a, running the N200b power wires to the input of the 3106 crossover and I wired only the 2405 tweeter to the HF of the 3106. The resulting sound of the L200b speakers was a 100% improvement and I am able to adjust the LE85 and 2405 independent of each other. Now comparing the modified L200b to my L300 the L200b sounds very respectable. I know it's not by the book but by the book sounded awful and having limited technical ability this worked out very well for me.

Initially, I did this same thing with my N1200/N7000. But on this site I had read horror stories of leaving a speaker tap left "untapped" and how in some cases at some frequencies, this presents a dead short across the amp.:biting:

So, I connected it all up as shown in the literature, but put an L-pad across the horn. This way I could run the crossover at "full" to the horn to the benefit of the tweeter, and just reduce the horn volume directly at the horn.

Zilch
02-04-2006, 10:31 AM
"Note that the attenuator of the mid-frequency network will vary the acoustic outputs of moth midrange and igh frequency drivers simultaneously."

[Both here, and above, I'm quoting from the 3100A family instruction manual.]

There should be plenty of UHF SPL available using the cascaded connection, and there is an advantage to having the MF and UHF "track," once established, when balancing against the LF.

The 3105/3106 have a LF filter in the midrange leg to prevent the UHF from going to the mid driver. It's important; therwise, both the mid and UHF play the same range, to the extent that the mid is capable of doing so.

Further, Majick47 did not eliminate the stock N200b HF boost circuitry, as I recall, as Toddalin did in his recent new derivative crossover design, also complicating the situation....

swire1953
02-23-2006, 05:28 PM
please email back info on where and how to get lx5's and n7000's for my just about perfect sovereign s8r's
scottswire@comcast.net

johnaec
02-23-2006, 07:05 PM
please email back info on where and how to get lx5's and n7000's for my just about perfect sovereign s8r's
scottswire@comcast.net (scottswire@comcast.net) Both those crossovers appear fairly regularly on ebay.

John