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yggdrasil
06-02-2005, 12:33 PM
About 6-8 weeks ago I made a pair of protoype Smith horns for my DIY JBL's. They were simply laid on top of the speakers, the L91's were removed and the holes blinded. "It will stay like this for a while." I told my wife, thinking 2-3 months. "OK" she said. 6 days later - "Time's up" she said (She also claims it was 8 days). :banghead:

Anyway I concluded that the DIY had to leave the living room (to another place with no wife interference) and be replaced by speakers that would not be subject to research & development. :D

Last week a pair of C-60's came up in Denmark, which is just (short) trip.

I have started looking over the cabinets and drivers.

First I hooked them up at very low volume. All drivers play. The lansaloy is gone completely, and was replaced by tape. I have now removed the tape.

Step one is obviously to order new surrounds. Is it possible to get JBL surrounds?

The speakers have been stored in a humid environment. Much of the lacquer is gone. There are a few deep cuts. I have spotted small dark spots all over the speakers (see close up). Are these spots ment to be there?

Also the back panel and the baffle needs repainting as the particle board is starting to come through the paint.

Do anyone have recommendations / schematics for new crossovers?

Lots of work to do, but it's worth it for house peace.:D

saeman
06-02-2005, 12:59 PM
Hello Johnny: I have restored/attempted restoration on a few pairs of Sovereign I's/Sovereign II's. Depending on your desired end result, restoration is possible. The pair you have is in Golden Oak. The early sov's finished in the lighter option were called Golden Pecan and shortly after they changed to Golden Oak. To my knowledge all were made from white oak but finished in different styles. Your pair looks to be 1974 vintage or later. In 1974 they started mounting the 15" drivers using 8 fillister head screws with tee nuts behind the baffle, instead of the traditional 4 clamp arrangement that they continued to use on their pro systems. The Sovereign was dropped from the product line in 1974 but was still available for a couple years after that on special order basis. The black specs in the finish are factory original. They were applied to the surface after the first coat or two of laquer. That was a very popular finish technique with Spanish/Mediterranean furniture in the late 60's and 70's. I have duplicated the black specs by taking a small brush with black paint on it (trial basis) and while holding it over the surface, tapping it with a stick to cause small specs of paint to splatter on the surface. If you look carefully at the existing finish you will notice that the base wood was not stained before being laquered. It appears that JBL used laquer with an added tint. Doing that they could achieve more depth of finish with additional coats of spray. After the desired color/shade was achieved they would finish with a clear product. When you strip the cabinets you'll see just how many coats they did use. I would say 8 - 10 minimum. I stripped a dark Country Oak pair that took me forever to strip thru the finish (never again), well maybe. If I can be of any additional help don't hesitate to ask. Rick

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saeman
06-02-2005, 01:06 PM
An additional comment on the back and baffle. On your Sovereigns the Baffle and Back are made of particle board. P.B. does not do well when subjected to excessive moisture. What you are seeing is the surface starting to crumble and rub off with the paint. Sand both surfaces and apply two coats of polyeurethane varnish to seal the wood surface. Then sand them smooth and repaint with black - good for a long time. Consider doing the same to the exposed cabinet bottom too. Rick

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Steve Gonzales
06-03-2005, 10:32 PM
Can't add much to Rick's input. I would LOVE to have a go at restoring them!!, Good Luck with them and I can't wait to see some pictures, Best Regards,
Steve Gonzales

saeman
06-04-2005, 11:58 AM
Further info on the black specs in the finish - On the first pair of sovs I restored I didn't bother with the black specs in the finish. The restoration came out real nice but something was missing with the appearance - it was the black specs. Don't let the seemingly tedious job of applying the specs turn you off. If you apply them after the first two coats of laquer are on and dry, any mistakes can easily be wiped off with a cloth lightly dampened with thinner. After doing a few you'll get the hang of it. I practiced before hand on a piece of cardboard just to make myself feel better.

If you want to achieve proper end appearance use laquer and not polyeurethane and make sure the laquer is SATIN and not semi-gloss or gloss. If you don't have a spray gun - RENT one for a couple of days. Laquer dries fast and you can spray several coats a day.

In my previous post I stated that Sovereigns were all made from white oak - Not necessarily true however white oak is what their production run cabinets were made from. Keep in mind that if you asked JBL for something special they would happily do it if possible. I bought a pair of Sovereign II's a few years back and found that they were made from Red Oak (entirely, not just the trim). These could well have been a special order. Has anyone out there seen anything else besides white oak ??? Rick

Steve Gonzales
06-04-2005, 12:31 PM
I do a bit of restoration work myself and remember using a toothbrush to make spatters. You need to thin your material to the right viscosity and put a small amount into a very shallow pan, then dip just the first 1/8" of the ends of the bristles into the material and then hold it over the surface that's to be spattered and run your thumb across all the bristles quickly, the same as if you were trying to get all the water out of it. Works for me, SG.

rloggie
06-04-2005, 12:39 PM
In restoring Soverigns, is it ever advisable to "spot" refinish? I purchased a mint condition C63 console cabinet recently. Mint except it has a water mark the size of my hand on the top edge. Can I refinish just the area damaged using the materials you've indicated? Or do I have to do the entire top at once?
Further info on the black specs in the finish - On the first pair of sovs I restored I didn't bother with the black specs in the finish. The restoration came out real nice but something was missing with the appearance - it was the black specs. Don't let the seemingly tedious job of applying the specs turn you off. If you apply them after the first two coats of laquer are on and dry, any mistakes can easily be wiped off with a cloth lightly dampened with thinner. After doing a few you'll get the hang of it. I practiced before hand on a piece of cardboard just to make myself feel better.

If you want to achieve proper end appearance use laquer and not polyeurethane and make sure the laquer is SATIN and not semi-gloss or gloss. If you don't have a spray gun - RENT one for a couple of days. Laquer dries fast and you can spray several coats a day.

In my previous post I stated that Sovereigns were all made from white oak - Not necessarily true however white oak is what their production run cabinets were made from. Keep in mind that if you asked JBL for something special they would happily do it if possible. I bought a pair of Sovereign II's a few years back and found that they were made from Red Oak (entirely, not just the trim). These could well have been a special order. Has anyone out there seen anything else besides white oak ??? Rick

saeman
06-04-2005, 12:56 PM
Hi Robin: Post a couple of pics showing the whole top and the area of concern. Refinishing a small area to match existing is way out of my league. Might also be too much for a very skilled antique restoration guy. Remember - the cabinet is 30 + years old and the UV has been hitting it all these years. Finish color and hardness has changed. I've tried all sorts of tricks on small spots and had very little luck. My very first choice is to always preserve the original finish and appearance coz you can NEVER totally duplicate it (just come close). Makes you wish it was just oiled walnut. Oak with multiple, multiple coats of aged laquer presents a real chalenge. And you're talking a spot as big as your hand. My bet is that you'll never hide it. Damn these people with wet booze glasses and flower pots anyway. Rick

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rloggie
06-04-2005, 12:58 PM
I'll post a picture later tonight when I'm home. This cabinet is really pretty. I didn't have a use for it, just happened on it.

Robin

Audiobeer
06-04-2005, 01:29 PM
Ifyou want to duplicate the spatter finish there is a product in an aerosol can i have used for spot repairs or complete refineshes and works really well. It's like any other paint can except it has a tip that spits the material in a consistant pattern. I would have to say on a finish that old it would be easier to strip it and start over. Wish you lived local as Steve said. That would be a enjoyable weekend project!

geowal3
06-04-2005, 04:54 PM
Audiobeer, can you ID "the product"? Thanks!

Audiobeer
06-04-2005, 06:25 PM
HPI Products off Fee Fee Road in Maryland Heights Missouri sells it. It's just called black Spatter distressing paint. If you need it I could pick you up a can the next time I go there and ship it ground. As for as spot repairs go on this forget it. The laquer has lifted just about everywhere. If you felt real lucky you could try some cheeze cloth and a apply laquer thinner one side at a time until you get all the laquer loose and pretty much melted away via rinsing and what's left will act as a sealer coat. Then scuff sand with some 360 tri mite cabinet paper just letting it slide across the surface without weight. Fill your spray cup with a cellulose laquer thinned and add a little orange NGR stain to it. Scuff sand it again. Apply another clear sanding coat, scuff sand and apply your "Distressing spatter paint" as it's called. Then top coat it. If and only if your lucky there will not be any fish eye on the surface due to contaminets. I say you will have a 1 in 10 chance that it works. You could try (It would work!) what is called a french polish but that takes finnese from experience. If you had a finisher local he could try what I am talking about and have it completed (One side whether it be a top or whatever) in two hours with the correct humidity.

yggdrasil
06-09-2005, 03:01 PM
Last week I got around to remove the drivers. Both cabinets smelled from long time humidity.

The cabinets were turned upside down and sanded slightly on all black areas. Then all the oak was masked. The paint have been sprayed on. I had hoped one coat would be enough, but tonight I have sprayed on coat 3.

The picture with both cabinets were taken after coat 2. Very large cabinets for my little workshop.

The drivers have signs of moist. The bullet on the 075's do not shine at all. The aluminum ring just under the back cap of both the 375's and LE15's have yellow fine flourish substance on them.

I had to sand (very fine sand paper) the bullets on a pair of 2402's used in a project I did this winter. It was very difficult to keep the direction of the sand paper at all times. Maybe they could be mounted on my wood turning machine? Will probably have to split the drivers, and remove the red wax seals. Any thoughts?

saeman
06-09-2005, 04:37 PM
Hi Johnny - Your problem with P.B. that has been exposed to excessive moisture will most likely not be solved by overcoating it with spray paint. Sanding it smooth and then spraying over it doesn't eliminate the surface and sub-surface layers that are soft and crumbling from the moisture. The spray paint goes on too thin and dries too fast. In an earlier post I mentioned using polyeurethane varnish (or something similar). Right now the P.B. is soft and crumbly on the surface and you can most likely dig into it with your fingernail. If you take a thinned and brushed on coat of varnish and let it soak in while it dries you will secure the P.B. surface layer and deeper layers depending on the drying time of the varnish and how heavy you brush it on. Let the first coat dry and apply another. Then sand smooth and spray black. Without first securing the surface you will most likely still be able to scratch thru the spray paint and remove P.B. with your fingernail. Leave a pair of speakers sitting in the garage for a couple of years and that's what you get. I've seen it many times. Rick

yggdrasil
06-09-2005, 04:45 PM
In an earlier post I mentioned using polyeurethane varnish (or something similar).
I overlooked that. But I do not understand what polyeurethane varnish is... Language barrier you know.:banghead:

Could it be a waterbased laquer?

saeman
06-09-2005, 05:18 PM
Hi Johnny: Polyeurethane varnish is just where the varnish industry has gone in recent years. It's nothing special and very common. Claimed to wear well, exibits good resistance to moisture and is poly (plastic) based in composition. It's available in different drying times and in different finish sheens. For your purposes on this project, ANY varnish (not Laquer) will do the job but get one that has a slow dry time, and thin the first coat, to allow maximum penetration into the P.B. Put the second coat on heavier with no thin added. Make sure the second coat is MAX dry and then block sand to a flat surface. It's possible that a third coat might be possible. I'm sure that you'll be pleased with the results. Regards - Rick

Audiobeer
06-09-2005, 05:19 PM
In Europe it is more commonly reffered to as Urethane product. Do you have that available? Europeans are ahead when it comes to switching over to the less toxic products and tend to use the waterbased topcoats.:D

saeman
06-09-2005, 05:23 PM
In Europe it is more commonly reffered to as Urethane product. You have that right?

Hi Audiobeer - We need to hook up some day - we're only a few hours down the road from each other and we share two similar passions - SPEAKERS and WOOD.

Audiobeer
06-09-2005, 05:24 PM
Sorry Riessen. I didn't see your post when I started the reply. What he said! :D

saeman
06-09-2005, 05:27 PM
Sorry Riessen. I didn't see your post when I started the reply. What he said! :D

The More The Merrier or If One Opinion Is Good, Two Is Better or or or or or

Audiobeer
06-09-2005, 05:44 PM
We will have to get together some time. Are you in Missouri, Il, or Kansas?

saeman
06-09-2005, 05:57 PM
We will have to get together some time. Are you in Missouri, Il, or Kansas?

Beer: I'm in Illinois, SW of Chicago. Only about 4 - 4 1/2 hours from Bush Stadium.

Zilch
06-09-2005, 07:14 PM
The drivers have signs of moist. The bullet on the 075's do not shine at all. The aluminum ring just under the back cap of both the 375's and LE15's have yellow fine flourish substance on them.

Any thoughts?Use 3M "Scotchbrite" metal finishing pad. A small piece (1" X 2") will let you control where you're polishing.

The yellow or white powdery corrosion is common. It comes off easily.

I would avoid opening the drivers if at all possible....

yggdrasil
06-10-2005, 12:40 AM
Use 3M "Scotchbrite" metal finishing pad. A small piece (1" X 2") will let you control where you're polishing.

The yellow or white powdery corrosion is common. It comes off easily.

I would avoid opening the drivers if at all possible....

Thanks, will look for it later today.

yggdrasil
06-10-2005, 12:42 AM
Hi Johnny: Polyeurethane varnish is just where the varnish industry has gone in recent years. It's nothing special and very common. Claimed to wear well, exibits good resistance to moisture and is poly (plastic) based in composition. It's available in different drying times and in different finish sheens. For your purposes on this project, ANY varnish (not Laquer) will do the job but get one that has a slow dry time, and thin the first coat, to allow maximum penetration into the P.B. Put the second coat on heavier with no thin added. Make sure the second coat is MAX dry and then block sand to a flat surface. It's possible that a third coat might be possible. I'm sure that you'll be pleased with the results. Regards - Rick
Ok. Have contacted a norwegian paint producer. Will have to wait and see if I get an answer.

bbrown
06-10-2005, 07:08 AM
You can also get expoxies that would work. Very, very thin, so it soaks into the PB and bonds everthing together. In the U.S. you can W.E.S.T. Sytem products. (W.E.S.T. = Wood Epoxy Saturation Technique). It was developed for marine use, i.e., strip building.

http://www.westsystem.com/

Bruce

yggdrasil
06-16-2005, 03:55 PM
I had already sprayed 3 coats of oil-based black matt paint on them. It was very thinned and soaked in well. After almost a week of hardening - the result is good.


I have started sanding on the top. One is very nice. The other one has a few loooong scratches. The grain has been cut. On some places probably through the veneer. Any advice?

On the second picture you see that some areas of the edge is gone. Any advice?

yggdrasil
08-16-2005, 01:48 PM
I just finished sanding today.

We have had some cold days now, so I got a lot of hours in the workshop.

Underneath the lacquer I found several wounds in the veneer. They were probably there from factory (see picture 2).

Anyway I have filled all the wounds.

yggdrasil
09-22-2005, 02:22 AM
Drivers cleaned. Woofers refoamed.

Had to break the red wax seals on one of the 075's to clean the gap.

yggdrasil
09-22-2005, 02:25 AM
That's a happy wife!

Small speakers does the trick every time...:blink:

yggdrasil
09-22-2005, 02:28 AM
All the drivers fit right back in.

yggdrasil
09-22-2005, 02:30 AM
In daylight.

yggdrasil
09-22-2005, 02:32 AM
This is what's left of the biggest wound in the veneer.

yggdrasil
09-22-2005, 01:42 PM
First I did 2 coats of lacquer.


Then I added the specks. Used a toothbrush.

Then I added a little color to the lacquer, thinned it a lot and added 14 coats...

Finished up with 2 coats of lacquer to give them a little glow.

I have played them a little now, and the first impressions are great.

But, will have to do something with the crossovers, probably build new ones.

yggdrasil
09-25-2005, 03:29 PM
These babies have been playing a few days now. I'll try to make a short summary.


Bass response is fast, with a good punch. Not quite as low as my much larger DIY's, but still very good.

Midrange is very dynamic, quite hard, with the ability to scare the shit out of the listener.

The high frequencies feel cramped.

What now?
My thoughts with these speakers was to keep them original, or at least very close to original.

Rebuilding the crossovers with new, high quality components will do something with both the midrange and high frequencies.

Do you have any recommendations/thoughts?

Ken Pachkowsky
09-25-2005, 06:33 PM
Ya did one heck of a good job on those. Congratulations:applaud:

Its obvious you spent many hours on it.

Ken

yggdrasil
09-25-2005, 08:45 PM
You've got what, LX5 and N7000?

Point being, I'd want to be able to restore everything to original at a later date.

Thanks for your input Zilch.

Yes, it is both LX5 and N7000.

And yes, I want to be able to restore everything to original.

In this step I am going to look at the crossovers. I have some ideas. At this stage it is more questions than answers, and a hell of a lot more complicated than the work intensive cabinet restoration.


Build new crossovers and put the old ones aside.
Rearrange them to avoid two crossovers in series.
Maybe change crossover frequenzies.
Maybe upgrade to newer design/other slopes.

I will be listening to them a lot since they have been placed in the living room, hooked up to the TV and everything...

Zilch
09-25-2005, 08:54 PM
Consider using full active crossovers with them. That way you can adjust everything until you get them sounding the way you like.

The 375 is acting as a direct radiator at the lower frequencies on that short horn....

yggdrasil
09-25-2005, 09:03 PM
Not a bad idea. Then I would be have to collect some more gear!

Used an Accuphase vintage electronic crossover ten years ago. Changed to passive with a very good result. Sold the Accuphase afterwards.

yggdrasil
10-27-2005, 05:03 PM
As I had the test equipment hooked up it was time to see if there was hard evidence to my ears scepticism....


I have set the LX-5 to lowest positon. The woofers has no chance of keeping up with the 375's.

In the first graph the N7000 have been set to minimum, i.e. only LE15 and 375 in this picture. Sampling rate is 48KHz.

Notice the top at 7KHz and the shift at 3KHz.

In the second graph I have set the sampling rate to 22KHz in order to emphasize the mid and lower frequenzies. I allways felt they are a bit thin.

:jawdrop:

It seems there has to be done some serious work on new crossovers.

Caledon Ken
12-02-2012, 08:39 AM
I realize this thread has been quiet for years but as my topic fits I thought I would post here rather than starting new thread.

I have a couple of Sovereign C60 S8R's, serial # 10892 and 10893. ( I tried to find that database someone was starting so I could add them and the components.) I live outside of Toronto Canada. I have some of the original instructions that came in an envelope on the speakers. They used to be attached to a very large Macintosh system which unfortunately is long gone.

Suffice to say they have been in the family for years and need some obvious work on the cases, especially the tops and bases. Not sure but was thinking of removing and replacing veneer.

In reading these forums it sounds like they also have to be reconed. They work at a basic level and they are used regularly. Twenty ones years ago I replaced one of the LX5's. Had to turn in the original as part of the fix.

I have some basic questions I was hoping to have answered to help me decide on a path forward... restore or leave alone.

1) For those that have restored the cases, about how many hours of labor did it take? Did you strip veneer or just rework?
2) Assuming a I get the pair of LE15A's reconed about how much should this cost?
3) Would I also need to get the PR15's done?
4) Are here any known pitfalls I should watch for in getting the above reconed? (Everyone you call is an expert and given these are forty plus years old most experts weren't even born.)

I'm reasonable good with my hands and electronics although I would be considered a rookie from what I read on these forums. Lot of very dedicated people.

Any advise, help or comments would be greatly appreciated.

HCSGuy
12-02-2012, 10:38 AM
First, post some pictures and LH members can give you input on the veneer.

I will give my input on the LE15's, as I have already travelled that road. I assume yours have the yellow "Lansalloy" surrounds, that harden over time. If yours have hardened but not cracked, you can try carefully softening them up with brake fluid - do a search on this forum for more info. If they have cracked, but the spider is flat and they are otherwise intact, you can replace the surround with a new foam one, which I'd recommend you have professionally done for your first one, as your drivers are valuable. If they have not been subject to moisture and the spider is flat, you shouldn't have to recone them just due to age. If you choose to have them reconed, make sure you specify (get it in writing) that a factory JBL kit is to be used, and also that it specify the impedance - yours are probably 16ohm, so make sure the 16ohm kit gets installed or your crossover point will change. A recone is probably $300 these days, and you may have to wait a while for a kit, if they are still being produced (I had to wait 6mos, but this was about 8yrs ago). Again, if you post pictures, you will get valuable feedback.

The PR15's should not need any work - your vintage should have the folded fabric surround that holds up fine.

Hope this helps...

Caledon Ken
12-02-2012, 12:27 PM
Thanks for the info.

The PR15's do have a sticky black fabric cloth where the yellow "Lansalloy" would be on the LE15A's. Apart from some cat hair from long ago and some real spider webs they look fine. Should be a pain to clean but doable.

The LE15A in what I will call the left hand cabinet, the 075 on the left, is showing minor cracks. The rest of the speaker looks good. I opened the case, by removing the PR15, and the spider looked okay but I did not remove. The LE15A on the right hand cabinet unfortunately is showing more age and there is a large crack around six inches long at the very edge. It shows bigger hair line cracks.

If I go with recone is that a "Lansalloy" replacement and replacement of the spider or just the "Lansalloy" for $300? Thanks for the advice on the JBL specific parts. If I proceed I will heed this advice.

I guess the bigger question is what do I do if JBL parts are not available? Is there another quality replacement?

I've taken your advise and I have included photo's of the enclosure tops. Everyone will notice these cabinets are dark brown. They have been in my possession for twenty five years and I did not refinish them and I can say with almost 100% certainty that my brother in-law did not refinish them. He just wasn't the type. I want to make them a dark reddish wood grain to match some other units I have.

HCSGuy
12-02-2012, 02:06 PM
I assume you mean cracks in the Lansalloy surround, and not tears in the actual cone. If the Lansalloy is cracked, it is not repairable and needs to be removed and replaced with new aftermarket foam, which my tech charges me $50 per driver to do. $300 is my estimate to replace the cone assembly (Cone, surround, and voicecoil) - if you have a really good tech who can recharge the magnet at the same time, you'll basically have a new woofer. Le-15A's don't degauss from use, but maybe overtime the magnet has lost some strength - I'm not sure I'd worry about it unless your tech has the facilities to do something about it. When they replace the foam, have them check the spider for sag.

Caledon Ken
12-02-2012, 02:34 PM
Thanks.

You sound as though you have really good tech. I will have to see if I can find one.

One last question... lets say it does have to be reconed and JBL parts are not available. Is there any other vendors you would feel comfortable with using.

Thanks again for all the information. I didn't even know you could get a magnet re-charged.

HCSGuy
12-02-2012, 06:00 PM
First find a good tech to have the driver evaluated. They should also be able to tell you if a recone kit is still available. Here's a link to another discussion looking for a tech in Canada - they're not far away from you:

http://www.audioheritage.org/vbulletin/showthread.php?33723-2245-re-cone&highlight=ontario

If you need a recone, which I doubt, and recone kits are no longer available, I would start watching Ebay for good condition replacements - there is no aftermarket kit with identical behavior.

Caledon Ken
12-03-2012, 06:05 AM
Yes the dealer in Mississauga isn't to far and I have to go to Mississauga to pick up an air compressor part.

Not much action on the pictures I've posted and I've started reading about wood refinishing. The actual enclosures don't look that complicated to build, of course that would take away from the authenticity.

Would you know if they made them from Particle Board for the sound qualities or to to keep costs down.

Thank you for your help, I call Audio Operations today.

Caledon Ken
12-08-2012, 12:45 PM
New issue. I was doing more exploring and investigation and determined that one of my 075 horns wasn't working. After an hour of switching horns between cases and then restoring them to their original cases I've determined the 075 horns are working. That is the good news, I guess.

So I started to study the wiring and it appears the amp drives the LX5's and the high end of the LX5 drives the N7000's. The N7000's drive the 375 and the 075. In the case where the 075 is not working the 375 is working.

Is it safe to assume this means the LX5 is okay and that the N7000 is faulty?

After searching this forum I assume they are repairable? Saw some pictures of the insides and found wiring diagram? Assuming it is the caps that are dead, or at least one, what is the best type of replacement capacitor that I can use to keep the original sound? Checked ebay, no N7000's for sale.

Thanks

yggdrasil
12-09-2012, 03:03 AM
Yes, it is safe to assume that the problem lies with the N7000. I would start with checking the L-pad.

The crossovers are the inferior parts of your speaker, and would benefit the most from an upgrade. Original caps are not that good, and the mechanical parts are worn by age. You could e.g.

replace l-pad's with fixed resistor l-pad
bypass cap's in all crossovers (easy) or replace the caps (not quite so easy, but still not complicated). IMO moderately priced polypropylene caps offers a good combination of price and performance.
hard-wire the selector of the LX-5

Johnny

Caledon Ken
12-09-2012, 10:11 AM
Thanks for the response Johnny. I did a search last night on one of the sub forums and found 256 threads using the word "Capacitor". Saved twenty threads that related to this subject. There is a ton of information out there but really no consensus. A number of different capacitor types id'ed, some people said they were to bright, some not bright enough, okay to parallel them, not okay to parallel, go with the originals as the designers had that sound in mind. Sort of like reading the financial markets.

I read a number of threads and I'm pretty sure I remember your avatar on threads discussing the "By-Pass" and that it should also be done in the LX5's. If I posted the LX5 and N7000 wiring diagrams would you be willing to tell me exactly where these by-pass caps should be place? (I will search N7000 on the forum for possible replacement part suggestions.)

I read the thread "N2400 Reveal" by Baron030. It was really informative although I'll bet the parts are not the same for the N7000. Still the pictures and concepts make me feel more comfortable. I am more than willing to replaced the entire guts of all the components as I'm expect this failure rate to continue and I would rather deal with this once and for all. I replaced one of the LX5's 20 years ago so I can only expect the other to fail and I'll bet the other N7000 is just waiting for the restore to be completed before it decides it is time. That said I don't have the knowledge to design so it will mean a lot more reading and posting.

Have you ever removed the "stuff" from an LX5. I've seen it called potting tar and wax in these forums. Seems nasty? Another search which I hope will produce results.

Thanks again for responding. Let me know if you would be willing to pinpoint bypass points and I will post wiring diagrams.

Ken

BMWCCA
12-09-2012, 11:42 AM
So I started to study the wiring and it appears the amp drives the LX5's and the high end of the LX5 drives the N7000's. The N7000's drive the 375 and the 075. In the case where the 075 is not working the 375 is working.

Is it safe to assume this means the LX5 is okay and that the N7000 is faulty?


I think you meant the N7000 controls the 075. It has (almost) nothing to do with the 375.

Check this thread: http://www.audioheritage.org/vbulletin/showthread.php?20826-Rebuilding-a-JBL-N7000-Possible

I'd focus on the L-pad in the N7000 and simply work it back and forth either dry or wet (Deoxit) with NO signal and see if that clears it up. Happened to my 55-year-old N2400s, too.

Caledon Ken
12-09-2012, 12:34 PM
Thanks. I will give it a try. Second person to suspect L-Pad. Spent the afternoon reading articles on N7000 and every other crossover. Looking to see if I could find a modern replacement that would give nice sound.

I must go down and check wiring again. I know the N7000 is connected to two drivers.

Interesting user name, I was a member many, many years ago.

BMWCCA
12-09-2012, 01:17 PM
Thanks. I will give it a try. Second person to suspect L-Pad. Spent the afternoon reading articles on N7000 and every other crossover. Looking to see if I could find a modern replacement that would give nice sound.

I must go down and check wiring again. I know the N7000 is connected to two drivers.

Yes, that's correct but the L-pad only effects the 075. Here's the correct wiring:
http://www.audioheritage.org/vbulletin/showthread.php?13986-Am-I-hooking-up-the-crossover-correctly

The 375 connects to the N7000 at the LF connectors, the 075 at the HF. The LX HF output goes to the N7000 input. I'm sure you have it correct.

Caledon Ken
12-09-2012, 01:47 PM
Thanks. Agree with all your wiring statements. My use of "Control" was to general.

I've done a search and I don't seem to see any posts on an easy way to open the L-Pad. ( Unless there is another way to get a cleaner into it. )

Failing any restoration of the L-Pad does anyone know the electrical specs on this unit. I see in the wiring diagram that one side is 8 ohms, the other is 60 ohms but no mention of wattage. The original parts states it is part number 13359 which I doubt I can use any more. I will continue to search.

Thanks you all for the help.

BMWCCA
12-09-2012, 03:57 PM
Failing any restoration of the L-Pad does anyone know the electrical specs on this unit. I see in the wiring diagram that one side is 8 ohms, the other is 60 ohms but no mention of wattage. The original parts states it is part number 13359 which I doubt I can use any more. I will continue to search.

The first reply I sent had a link to a page here that mentioned replacement L-pads from Parts Express:


If you have problem of scratches with the pad, try this :
http://www.partsexpress.com/webpage....ctGroup_ID=196 (http://www.partsexpress.com/webpage.cfm?webpage_id=3&CAT_ID=48&ObjectGroup_ID=196)

model : 260-248 OR 260-262

the 262 are big ones !

yggdrasil
12-10-2012, 12:23 AM
Attached is a wiring diagram for LX-5 with how to hard-wire for middle position.

4313B
12-10-2012, 05:35 AM
Thanks for the response Johnny. I did a search last night on one of the sub forums and found 256 threads using the word "Capacitor". Saved twenty threads that related to this subject. There is a ton of information out there but really no consensus. A number of different capacitor types id'ed, some people said they were to bright, some not bright enough, okay to parallel them, not okay to parallel, go with the originals as the designers had that sound in mind. Sort of like reading the financial markets.
Well... you could just bias Solens... :D

The components you have are good enough to bother.

Caledon Ken
12-10-2012, 06:51 AM
Thanks BMWCCA for the specifics on the L-Pad. Guess I didn't read the thread thoroughly. So now I have the L-pad solved. This looks like the same L-pad that Baron030 used in his N2400 Reveal thread.

Thanks Johnny for the wiring diagram on the LX5. Understand the red wires, they are jumpers. Is the lime green in the drawing a polarized capacitor and if so would you have any suggestions on its properties?

I know I still don't understand where to by-pass caps in N7000's. Is it as simple as soldering in a by-pass capacitor for each existing capacitor in series with the existing capacitor? (Would a 0.01uF Theta AudioCap be acceptable for this by-pass?)

Yes 4313B, I would like to restore. The costs are starting to mount and I haven't really investigated the cabinet restoration. That is where the real labor will come in. It's starting to snow here so I will have the time.

4313B
12-10-2012, 07:45 AM
Is it as simple as soldering in a by-pass capacitor for each existing capacitor in series with the existing capacitor? (Would a 0.01uF Theta AudioCap be acceptable for this by-pass?)Yes.

grumpy
12-10-2012, 10:32 AM
... in parallel.

4313B
12-10-2012, 11:26 AM
:rotfl:

Glad you're paying attention Grumpy!

Caledon Ken
12-10-2012, 01:38 PM
Thank you all. I have taken the liberty to redraw this simple change on the wiring diagram from the library. The original owners maintain all their rights to the original wiring diagram and maintain any implied copyrights.

In my previous note I suggested 0.01uF Theta AudioCap which I borrowed from Baron030's post.

Could I ask that members look at this drawing and comment. If it is wrong I will remove and redraw. Thanks

yggdrasil
12-11-2012, 12:38 AM
The drawing is correct. The values of the bypass caps are not important as long as it is less than ~1/10 the value of the capacitor it bypasses. Beware that the effect of bypassing in the N7000 is limited unless you do the same in LX-5. Reason : crossovers are daisy chained.

Picking up on your question in another thread:

(There were actually lots of items in this thread that peaked my interest, the horn discussion between 500-1200Hz and the better crossovers)

If there is a better cabinet that would produce a better sound I would be interested in determining whether it would be easier to acquire rather than refinish.
There are many issues you could address in your speakers. However - if you want to take them all on - you need to ask yourself: Do I want to use these drivers? The point being - A complete rework with new cabinet and crossover design deserves a set of drivers that address the shortcomings in this driver combination.

That being said: The C60/S8R is more than good enough to be enjoyable for many years with modest crossover uprgades.

Sanding down the cabinets, staining and varnishing is not a small job on these cabinets with all the cabinet details. But then again it is nothing compared to designing new cabinets and building them from the ground up to furniture quality.

Caledon Ken
12-11-2012, 08:20 AM
Thanks Johnny.

Re the LX5's. In another thread I learned these are potted in bee's wax and another member discussed how to melt and remove. This will allow me access to components.

I have two separate questions.....

In post #56 of this thread you posted an LX5 drawing. In post #58 I asked you about a question on the lime green in the drawing. This wiring diagram you provided was for the bypass of the LX5. Two red wire jumpers and I think the lime green is a capacitor. Could you confirm and provide values.

Given I'm going to by-pass the N7000 caps as per your recommendation and in keeping with your recommendation to bypass LX5 caps could you tell me which of the four caps need to be by-passed in the LX5. From by limited knowledge I assume it is just capacitor C4, with a value 16uF, which is part of the HF circuitry.

It could be the answers to the two questions are the same. Your lime green cap, or what I think is a lime green cap, between e6 and s12 in effect is a parallel bypass of C4 if I'm reading the drawing correct.

For these by-pass caps I saw your 1/10 recommendation of the cap being bypassed, thank you, but for voltage I assume anything will do, eg, 250v, 400v, 600v? The .01uF seem to have very high voltage ratings.

Thank you again for your help.

yggdrasil
12-11-2012, 04:42 PM
The drawing is a simple wiring diagram showing the physical layout inside a LX-5.

The lime green is a capacitor. Just solder it in like the drawing. Solder in the red hard-wiring. Put the selector in middle position and leave it there. I believe I used 1.5uF bypass cap in the LX-5.

The voltage rating of polypropylenes are normally more than sufficient. 50V should do the trick, so any of the suggested ratings are good.

Johnny

Caledon Ken
12-12-2012, 04:19 PM
Thank you sir. I really don't want to "Kill" the LX5's so I will just install the capacitor. I assume this will allow the signal through to the N7000 and I will put by-passes on each of these.

Thanks everyone for your help.

I'm going to start a new thread on the refinishing of cabinets.

Mr. Widget
12-13-2012, 09:06 AM
Thank you sir. I really don't want to "Kill" the LX5's...From your other threads, I think I have a handle on what you are after. I would seriously consider pulling the original crossovers out of the circuit and build new ones from the ground up. Even if yours are working properly, simply bypassing, cleaning etc. will not offer the best sonic performance the drivers are capable of. I had a ten year old pair of S7s back in the '70s. I realize they are not quite the same, but close enough... I had LX5s and N8000s and slots above my mids... they never sounded as good as I thought they should until I built entirely new crossovers. I just built textbook second order butterworth networks with higher quality parts and no autoformers and the sound improved markedly. With today's crossover design software a much more sophisticated design could be implemented and an even bigger improvement could be realized.


Widget

Caledon Ken
12-13-2012, 02:39 PM
Mr. Widget, thanks.

I would build XO's right from scratch, if I had a design. I started down the path of reading about how to design but quickly got frustrated as I simply did not have the test gear or sound generation to sample the drivers as it was being outlined. Finding the individual driver specs on this old gear proved to be great practice for my internet skills but provided no usable data. I never got to software as I just figured it would be looking for values that I could not provide.

Is there a particular version of software you could recommend. I would be more than willing to research to see what is involved in designing. As I've stated I'm expecting issues with the LX5's and N7000's as they are all very old components, some of which have already failed. Even finding replacement parts that fit the boxes is proving a challenge, especially the inductors.

I got some bad news yesterday, from one of the members, that very little of the cabinets is solid wood so refinishing these cabinets may turn out to be a real challenge. I think you called them "furniture". Through the excellent knowledge in this forum I've learned about the sound gap of horn and overall elevation issues.

If the glass was half empty I would be looking at under performing XO's with dying parts, a missing sound band with difficult to refinish cabinets that have a very low center of gravity.

If the glass was half full, I enjoy these speakers, I like their sound and I would really like to make them even better.

If you could point me to the XO software or vendor name I can Google and explore XO design.

Thanks again for responding. I appreciate the help and wisdom everyone is sharing.