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View Full Version : JBL L110 restoring crossover-networks



jan_slagman
07-15-2008, 04:42 AM
Hi everybody,

Lately my JBL crossovers have been restored with MKT capacitors.
The pics show you the difference.

Kind regards,

Jan Slagman
The Netherlands

http://img152.imageshack.us/img152/8742/jbll110crossovermg5.jpg (http://imageshack.us)
http://img143.imageshack.us/img143/7117/jbll110crossovernetworkdt9.jpg (http://imageshack.us)
http://img143.imageshack.us/img143/7117/jbll110crossovernetworkdt9.74e2927fd8.jpg (http://g.imageshack.us/g.php?h=143&i=jbll110crossovernetworkdt9.jpg)http://img152.imageshack.us/img152/8742/jbll110crossovermg5.3376daba69.jpg (http://g.imageshack.us/g.php?h=152&i=jbll110crossovermg5.jpg)

coherent_guy
07-15-2008, 07:23 AM
Luckily, most of those MKT's fit in the space provided for the old caps! Looks like yours are early L110's like mine, without bypass caps, but now they have them! How do they sound now?

How did you get the network boards out of the cabinets, I haven't touched my L110's yet as I've been working with compression drivers, horns, and CC X-overs on my L300 wannabees, but I might get to them this winter.

Are you doing a restoration, or just an improvement?

jan_slagman
07-15-2008, 04:05 PM
Hi Coherent Guy,

The JBL L110's sound more balanced and detailed now, without a trace of harshness. They produce a pretty wide soundstage. You can losen the six screws at the backside of the speaker, but first you have to remove the loudspeakercomponents. You can reach the X-over through the hole of the removed bass-speaker. It is partial a restoration and partial an improvement. The JBL L110's missed the bezels and knobs to adjust the mid-and high frequencies. Research pointed out one midrange had broke down and one of the tweeters had minor dents. It was member Larry Bacon who helped me to gather the parts. Without his support it wouldn't have been that easy to finish the JBL L110's and i really appreciate his help in this matter. By the way you can download the service manual from the internet. See the URL mentioned below.

http://www.retrevo.com/support/JBL-L110A-Home-Theater-Systems-manual/id/597dj382/t/2/

Kind regards,

Jan Slagman
The Netherlands

coherent_guy
07-16-2008, 08:30 AM
Yes, you sure need to take them almost completely apart to access the network, but not a bad job at all really. Thanks for the link to the service manual, it may come in handy, the network schematic is available on this site of course.

Do you have any plans to change any of the inductors to air core types, that is usually an improvement worth doing. I sure wish I could get new diaphragms for the 033's, but I doubt they exist. Mine still work but are a bit old... the woofers have been reconed although I don't know if that can be done anymore either.

I've always liked the LE 111A woofer although it is a bit odd in some respects. Seemingly very fast on transients, it does not have the capability of loud very low frequencies, being rather excursion limited. I've always dreamed of it matched with an 18" woofer crossed at about 50 Hz.

I would recommend (if you haven't done this) putting the '110's on low stands. I use some 18" (45cm) high ones.

Good luck with your tune up!

jan_slagman
07-18-2008, 02:20 PM
Hi Coherent Guy,

For the moment I don't have any plans to change the inductors. You probably won't find any diaphragms and you just have to search for parted out 033's on Ebay.
As far as i am informed the woofers can't be reconed anymore, have a look at:

http://www.jblproservice.com/pdf/Transducers%20Parts%20List/Transducer%20Parts%20List.pdf

I already have the JBL L110's on heavy duty stands !

With kind regards,


Jan Slagman
The Netherlands

4313B
07-18-2008, 03:34 PM
Very nice Jan!


As far as i am informed the woofers can't be reconed anymore, have a look at:All the recone kits are still listed...


LE10H $200.00 C8RLE111H 31385 21813 1-P-6 A6 Wt 3
LE10H-1 $238.00 C8RLE10H-1 31385 21813 1-B-6 Wt 3
LE111A $230.00 C8RLE111A 31385 21813 M 1-B-6 Wt 3
LE111H $200.00 C8RLE111H 31385 21770 1-B-6 A6 Wt 3


Do you have any plans to change any of the inductors to air core types, that is usually an improvement worth doing.His are all air cores (JBL did also use iron cores in early runs). Furthermore two of them have very specific DCR's necessary (~ 7.5 ohms) for the network to function correctly.
I sure wish I could get new diaphragms for the 033's, but I doubt they exist.New kits are long gone. :( Fortunately they are phenolic. :)

I've always liked the LE 111A woofer although it is a bit odd in some respects. Seemingly very fast on transients, it does not have the capability of loud very low frequencies, being rather excursion limited. I've always dreamed of it matched with an 18" woofer crossed at about 50 Hz.It is odd, way too powerful for its own good. I think the Qt on that thing was very near the Qt on the old 124/2203, another transducer that was extremely over damped. The 136/2231 was less so only by virtue of its larger size. The 2235H was less powerful and better balanced. The LE10H/LE10H-1/LE111H found in the last version of the L110 was less powerful and better balanced. All the ten-inch systems seemed to work very well crossed to B380's or B460's back then.

jan_slagman
07-19-2008, 01:47 AM
Hi 4313B,

Thanks for your valuable addition ! Can i change my 111A woofer for a 111H without any consequenses regarding the crossover network or other adjustments ?

Kind regards,

Jan Slagman
The Netherlands

4313B
07-19-2008, 05:22 AM
Your network is the N110 network (I can tell by the 36 uF cap in the photo above). You would want to use the N110A network with the LE10H, LE10H-1 or LE111H.

You might send a PM to LRBacon (http://audioheritage.org/vbulletin/member.php?u=5073) and ask him if it would be worth the trouble. I think he has both and can A/B them.

coherent_guy
07-19-2008, 07:58 AM
How could I forget the inductors are air cores, as noted on the schematic, which I have! They kinda don't look like it at first glance in the pics. The small ones always call out to me to be replaced, but the designed-in resistances are a factor, as you mention.

4313B, I don't get your point that the 033 dia's are phenolic... they are, but so? :o:

Too powerful for their own good... I know what you mean regarding the LE111A's. One of mine would occasionally experience a strange phenomenon, where, on a low bass tone at high volume, would seemingly have such a long over-excursion, the voice coil would leave the gap and then the cone would get stuck outwards, the rear of the VC resting on the pole piece! No sound would come from that transducer afterwards! I was able to get the VC back into the gap by some miracle of careful manipulation, and it did not seem to scrape afterwards. That one was a recone done by some place in Orlando, FL., if that could be a factor, the amp a mere 100 watt Adcom.

Have you ever heard of such a thing, or experienced it? I'm assuming the VC was resting on the pole piece, what else could it be? I think I only had that happen to the one speaker, I haven't done that in years fortunately... or tried to! :blink:

The recone kits are available, excellent!! Better get some while I still can, although I need a pro to do the work, I guess. My '110's are due for an overhaul.

Thanks for the info 4313B, the L110 being their great grandfather or something like that.

Come on Jan, keep the LE111A, they aren't bad, just an over-achiever ;)

jan_slagman
07-19-2008, 10:49 AM
Hello Coherent Guy and 4313B,

Larry already informed by mail. Thanks for your input guys ! No, i won't sell these L110's that soon. I just will keep them in my collection.

Kind regards,

Jan Slagman
The Netherlands

jan_slagman
07-20-2008, 02:22 PM
Hi Coherent Guy,

For the moment I don't have any plans to change the inductors. You probably won't find any diaphragms and you just have to search for parted out 033's on Ebay.
As far as i am informed the woofers can't be reconed anymore, have a look at:

http://www.jblproservice.com/pdf/Transducers%20Parts%20List/Transducer%20Parts%20List.pdf

I already have the JBL L110's on heavy duty stands !

With kind regards,


Jan Slagman
The Netherlands

Sorry Coherent Guy,

I overlooked the recone kits because i forgot the addition LE !

With kind regards,

Jan Slagman
The Netherlands.

Hadro
07-26-2008, 04:49 AM
Folks, I am new here ,so I apologize if I am asking things that have been asked before.

I have a pair of 4313b's I inherited from a sibling. The cabinets have a slight water damage on the bottom (mild expansion), but are otherwise fine and whole.

The woofers need re-edging and maybe reconing, eventhough the paper looks just fine.

At the risk of sounding heretical, I would like to ask: should these woofers need reconing, how important is it from the perspective of sound quality to use original jbl kits for the recones? I was told by some that aftermarket kits sound just as good but cost half the price. Others say there is significant difference. I would very much appreicate if anyone could shed some light.



Very nice Jan!

All the recone kits are still listed...


LE10H $200.00 C8RLE111H 31385 21813 1-P-6 A6 Wt 3
LE10H-1 $238.00 C8RLE10H-1 31385 21813 1-B-6 Wt 3
LE111A $230.00 C8RLE111A 31385 21813 M 1-B-6 Wt 3
LE111H $200.00 C8RLE111H 31385 21770 1-B-6 A6 Wt 3

His are all air cores (JBL did also use iron cores in early runs). Furthermore two of them have very specific DCR's necessary (~ 7.5 ohms) for the network to function correctly.New kits are long gone. :( Fortunately they are phenolic. :)
It is odd, way too powerful for its own good. I think the Qt on that thing was very near the Qt on the old 124/2203, another transducer that was extremely over damped. The 136/2231 was less so only by virtue of its larger size. The 2235H was less powerful and better balanced. The LE10H/LE10H-1/LE111H found in the last version of the L110 was less powerful and better balanced. All the ten-inch systems seemed to work very well crossed to B380's or B460's back then.

LuckyST
03-02-2010, 09:00 AM
Hi. I recently reconed my l110s and discovered one other problem.

there's something wrong with the crossover. While I'm turning the tweeter crossover, I can hear noise, and the midrange doesnt seem to produce any noise at all (I tried it on its own, and the speaker is alright).

could you give me some tips on how to reach the crossover panel without damaging the speaker?
and do you have any idea what might be the problem?

also,... while I'm already in there, any other things I could do to the crossover to make sure it's at its best :)

robertbartsch
03-02-2010, 09:35 AM
I would not repair a busted vintage JBL speaker without a genuine JBL OEM kit (VC, spider, cone, surround, etc.) where the labor is done by a JBL service center.

If only your surrounds need replacement, this can be done without much expense. Surrounds last about 15 or 20 years, at most.

If I had a busted woofer and no OEM kit was availible, I would (i) look for a replacement pair of woofers being sold from a source such as Fleabay, (ii) replace the surrounds on these, if necessary.

jcrobso
03-02-2010, 10:49 AM
Hi. I recently reconed my l110s and discovered one other problem.

there's something wrong with the crossover. While I'm turning the tweeter crossover, I can hear noise, and the midrange doesnt seem to produce any noise at all (I tried it on its own, and the speaker is alright).

could you give me some tips on how to reach the crossover panel without damaging the speaker?
and do you have any idea what might be the problem?

also,... while I'm already in there, any other things I could do to the crossover to make sure it's at its best :)

Did you try turning them back and fort slowly a few times? Many times this will clean the contact surface and the will work.

LuckyST
03-02-2010, 03:29 PM
Did you try turning them back and fort slowly a few times? Many times this will clean the contact surface and the will work.


I'll try to do it some more, but I doubt it. (would feel fullish if that fixed it :D )
The biggest problem is the midrange speaker - I removed it from the system and it works, so I guess the crossover doesnt seem to be letting the signal reach it.


edit: tried it and nothing happened. the tweeter dial still makes a "scratchy" noise, and the midrange speaker still doesnt get any signal.

LRBacon
03-03-2010, 08:06 AM
I'll try to do it some more, but I doubt it. (would feel fullish if that fixed it :D )
The biggest problem is the midrange speaker - I removed it from the system and it works, so I guess the crossover doesnt seem to be letting the signal reach it.


edit: tried it and nothing happened. the tweeter dial still makes a "scratchy" noise, and the midrange speaker still doesnt get any signal.


Still no output from the midrange if you turn the L-pad all the way clockwise? If you get output at the full clockwise position and nothing up to that point, that L-pad is probably open. If still nothing at full clockwise position then the wiper may no longer be contacting the resistor.

To access the L-pads you must remove the woofer, then the plastic bezel, which is glued in place on the cabinet around the shaft extension, gently with a flat blade screw driver. The black plastic shaft extension should pull off easily with a pair of pliers. The L-pad is held in place by a nut and a flat washer on the threaded section of the shaft. You could use a deep socket wrench to remove the nut but you may also use needle nose pliers. Once the L-pad is loose use a wire jumper between the middle and the right terminals (shaft side facing you with terminals down) and see if you get some audio out of the midrange speaker, be sure to tape the ends of wires for the woofer so they don't touch. If you get some audio out, then the L-pad is defective. If no audio you have a problem with X-over network. I do have some spare X-over parts, mostly N110, not N110A. The L-pads are the same in either system. I may be able to help you out with parts, PM me if you do.

Larry

LuckyST
03-04-2010, 08:50 AM
I did a test with a multimeter, and seems that the 2.5ohm resistor failed.

I bypassed it with a wire, and the speaker worked. I still need to check the Lpad just to be safe.


anything about ordering resistors I should worry about?
btw, my board is n110.


edit:
any tip on where I might find the correct resistor 2.5ohm,10 watts,+-10%? I have trouble finding the exact match.

LRBacon
03-04-2010, 11:08 AM
I did a test with a multimeter, and seems that the 2.5ohm resistor failed.

I bypassed it with a wire, and the speaker worked. I still need to check the Lpad just to be safe.


anything about ordering resistors I should worry about?
btw, my board is n110.


edit:
any tip on where I might find the correct resistor 2.5ohm,10 watts,+-10%? I have trouble finding the exact match.

If you can't find one send me your address and I'll mail you one.

Larry

LuckyST
03-05-2010, 07:26 AM
I replaced the 2.5Ω10W resistor with a 2.5Ω9W one and the speaker came to life. No more crackling noise when turning on the tweeter lpad, and the midrange speaker is working.

I'll still try to find a 2.5Ω10W one, since I'm obsessive compulsive about these things.

also, how will this 1W reflect?

LRBacon
03-05-2010, 07:34 AM
I replaced the 2.5Ω10W resistor with a 2.5Ω9W one and the speaker came to life. No more crackling noise when turning on the tweeter lpad, and the midrange speaker is working.

I'll still try to find a 2.5Ω10W one, since I'm obsessive compulsive about these things.

also, how will this 1W reflect?


I doubt it will make that much difference as long as you don't play them at their maximum all the time.

Larry

grumpy
03-05-2010, 07:34 AM
~ 0.5dB less regarding how loud you can play... long term... on average...
i.e., nothing at all except how you feel about it. :)

LuckyST
03-07-2010, 07:28 AM
the tweeter lpad is still makes noise when I'm adjusting it. I guess there's some dirt in it? Any good way of cleaning it out?

also, I took a closer look at the N110A and mostly the difference is that they added .068uF caps on top of N110 ones?

what are the benefits of those changes?

LRBacon
03-07-2010, 08:30 AM
the tweeter lpad is still makes noise when I'm adjusting it. I guess there's some dirt in it? Any good way of cleaning it out?

also, I took a closer look at the N110A and mostly the difference is that they added .068uF caps on top of N110 ones?

what are the benefits of those changes?

Just follow those directions I posted earlier, except remove the L-pad for the tweeter. Just spray some contact cleaner such as Deoxit into the vent holes on the back of the L-pad and turn it back and forth several times. You could also turn the L-pad numerous times back and forth through its rotation without removing it. This may clean off the corrosion on the contact area. As long as the tweeter does not cut out, once you've set the level where you want it, you could just leave it alone.

The N110A network is an updated version of the original N110 for the use of the LE111H woofers which are different acoustically from the LE111A woofers used in the original L110 and also incorporated the use of bypass capacitors (the .068 uF capacitors). Check out these links:

http://audioheritage.csdco.com/vbulletin/showthread.php?t=3555

http://audioheritage.org/vbulletin/showthread.php?t=14034&highlight=bypass+capacitor

DonQuixote99
12-03-2015, 08:42 AM
Yes, you sure need to take them almost completely apart to access the network, but not a bad job at all really.

It was bad for me, someone left a broken allen-wrench end in one of the midrange screws. Had to basically drill it out. The screws are hardened....

But here's good news for others out to recap this speaker. Having done that, I find you don't have to remove the mid-ranges to work on the network. You don't even have to remove the L-pads from the front of the cabinet. There is enough slack in the connecting wires to enable you to get the network board out of the woofer hole and work on it on top of the cab.

The network board may seem like it's glued-down, but it isn't. After you remove the six screws, just give it a rap on the back and out she comes.

You probably do want to pull the tweeters to disconnect them--those wires seem just a tad short to leave them hooked-up. And I'd recommend pulling the L-pads to apply deoxit to them, even if they seem OK. But at least you don't have to mess with the midranges....