Restoring wife's father's/grandfather's JBL C38 WX

[milkshake]

I'm new to the forum here, I hope to share some of the documentation for the speakers that was passed onto my wife, as well as get some info about where to start with these speakers.

My wife's father recently passed away. He was a wonderful man, always helping others selflessly and putting his family before his own needs. His wife has many stories of him using bonuses from work or prize money or other windfalls to buy her a sewing machine or a clothing dryer instead of getting anything for himself. The whole family has stories of his selfless bravery in the face of danger -- I swear half the family members had a story about how he literally saved their life -- sometimes on more than one occasion! One of his great loves was music played on high quality speakers, and he always told my wife stories of how incredible these speakers were, which he inherited from his father. He told her that he hoped to "get them going" again someday. No specifics on what might be wrong with them.

Some folks at audiokarma forums have made a couple suggestions such as using butylene treatment on the surround, and PVA to repair a small spot of damage on one of the subs. (Any recommended sources for these compounds?) They've also helped me ID some of the parts -- I have C38 cabinets with D130 woofers and Wolverine CR35 crossover + tweeter.

Having trouble with the file upload in the forum here, so this is a link to a Google Drive folder with all the pics.

So far I'm planning to purchase an amplifier for testing, I have basic electronics/soldering skills and can follow instructions with a multimeter, but am by no means an expert. Is there a good place to start with testing beyond plugging them into an amp and seeing if I get sound?

I've learned from past experiences working with old beloved tech -- consult the experts first, they often know everything to look out for and how to get started.

Any guidance is greatly appreciated -- I'd love to get these going again for my wife in honor of her father's memory, and because I too appreciate good speakers and music! I've been an avid listener and vinyl collector since I was 8 (mid 40s now), and a DJ since I was 18. Between the wife and I (she is also a vinyl DJ) there are quite a few records in the house, in fact that's all we listen to. Even when we're cooking or cleaning we still bother with the changing of the records despite the extra hassle! Would love to hear tunes on these and see the smile on her face when her family's speakers are working again.

Any assistance or info greatly appreciated.

Thanks,

--M

[speakerdave]

Welcome to the forum and good luck with your project.

I'm going to jump ahead with my first response, and that is to forewarn you that if you try to use these speakers for DJing, you will ruin, i.e. tear, the integral paper surrounds on the D130's, especially if you use high sound level, rapidly if you try to boost the bass with EQ. Those cone/surrounds diaphragms are irreplaceable except with third-party product.

The tweeter is like the Electro-Voice T35, but if it is Wolverine like the crossover, it may not be exactly like; Wolverine was E-V's budget line.

The Cabinet is, I believe, the smallest one available from JBL in that era. A fifteen-inch driver is in fact cramped in that volume.

As items for sale, should you decide to go that way: If the D130's are good, they have some value in the used market because there is a diminishing number of them and they are sometimes preferred for light-duty guitar use. The T-35's, if they are that, will also find a buyer if they have the original diaphragms, which they probably do, because good replacements are, at this point I believe, no longer available. The last business that could successfully service those tweeters to factory standards has been closed and it is unknown what will happen to the tools and inventory.

Not a huge windfall, but you could get some useful cash.

I would not put a lot of money or time into trying to make these speakers useful for hi fi by today's standards. As a nostalgia rush, on the other hand, they may do quite well. Vinyl Elvis Pressley or Hank Snow, say.

[milkshake]

Welcome to the forum and good luck with your project.

I'm going to jump ahead with my first response, and that is to forewarn you that if you try to use these speakers for DJing, you will ruin, i.e. tear, the integral paper surrounds on the D130's, especially if you use high sound level, rapidly if you try to boost the bass with EQ. Those cone/surrounds diaphragms are irreplaceable except with third-party product.

The tweeter is like the Electro-Voice T35, but if it is Wolverine like the crossover, it may not be exactly like; Wolverine was E-V's budget line.

The Cabinet is, I believe, the smallest one available from JBL in that era. A fifteen-inch driver is in fact cramped in that volume.

As items for sale, should you decide to go that way: If the D130's are good, they have some value in the used market because there is a diminishing number of them and they are sometimes preferred for light-duty guitar use. The T-35's, if they are that, will also find a buyer if they have the original diaphragms, which they probably do, because good replacements are, at this point I believe, no longer available. The last business that could successfully service those tweeters to OEM standards has been closed and it is unknown what will happen to the tools and inventory. Not a huge windfall, but you could get some useful cash.

I would not put a lot of money or time into trying to make these speakers useful for hi fi by today's standards. As a nostalgia rush, on the other hand, they may do quite well. Vinyl Elvis Pressley or Hank Snow, say.

Thanks for the info Dave!

We have good DJ speakers for when we want to get loud and heavy, I imagined these for light listening duty. The D130s look good to my eye, just a small spot of damage near the edge of one. Another expert on Audiokarma suggested it could be repaired easily w/ PVA compound.

[MoD]

Mm, not a really hi-fi... but, build JGBL 4530 and put them in. It might sound decent. Decent with flavor. See If You like it.

[Riley Casey]

Looks like a fun project and a worthwhile bit of nostalgia as these were likely pretty prominent pieces of furniture in your wife's house growing up.

First step is to learn what kind of shape they're in. Any amp including one you might currently use for DJing will server for testing. Get a tone generator app for your phone - https://studiosixdigital.com/audioto...ools-platform/ - is the industry standard but there are probably free ones as well. Connect the phone to the amp and sweep a sine wave tone from 50 hz to about 5000 hertz and listen for any distortion or extraneous sound like buzzing. The volume should be slightly annoying but no more as excess level from pure tones can easily damage speakers. This test will inform your next steps. Cabinet joints may be loose and require reglueing. The tweeter level control will likely be oxidized and require cleaning with contact cleaner like DeOxit. The capacitors in the tweeter crossover cans may require replacement. Latter versions of these woofers came with a rubberized compound all the around the 'W' shaped surround so repair with butylene wouldn't be out off order.

One question you'll want to decide is if you want to keep these as 'museum' piece examples in memory of their original owners or 'tart them up" with parts and modifications that will make them more hifi and better examples of the speakers of their day. Plenty of opportunities for new and better rabbit holes here.

...-- I'd love to get these going again for my wife in honor of her father's memory, and because I too appreciate good speakers and music!....

[BMWCCA]

You didn't ask value questions, but you're going to get those answers anyway! Good on you for wanting to play them.

My D130s date back to my Dad when I was but 5-years-old. And they're still playing strong. Your cabinets are about as small as they come for the D130, and that was on purpose for wife acceptance. I have the larger C35 and C37 and even with that volume the D130 is really not a capable woofer in the realm of today's music. It is an extremely pleasant speaker to listen to acoustic guitar, cello, and most orchestral recordings. And don't tell the Grateful Dead that it can't rock!

But your cabinets will cramp it and, at least within the past few years, the legs on your cabinets have been worth more than the entirety of the rest of the system. The D130 was actually sold as a full-range speaker without a tweeter as a basic system that could add the tweeter later. Without seeing your crossover wiring, it could be connected that way now. Or at least you'd have no problem hooking it up that way for testing/listening if there's a problem with the Wolverine setup.

Repairing a tear in a D130 cone can be easily accomplished by saturating some thin paper in a diluted glue (Elmer's, Aleene's) and patching from the rear where it won't be seen in front. Then enjoy them with some fully instrumented recordings. It's probably not worth the money to attempt to add the original JBL 075 tweeter and crossover they were normally paired with. You can buy entire new/used systems that will perform better for less than the cost of those components.

Have fun and keep them for what they are. I still have mine—as well as dozens of other JBL pairs. But the D130 is what got me started!

[milkshake]

... Connect the phone to the amp and sweep a sine wave tone from 50 hz to about 5000 hertz and listen for any distortion or extraneous sound like buzzing. The volume should be slightly annoying but no more as excess level from pure tones can easily damage speakers. This test will inform your next steps. Cabinet joints may be loose and require reglueing. The tweeter level control will likely be oxidized and require cleaning with contact cleaner like DeOxit. The capacitors in the tweeter crossover cans may require replacement. Latter versions of these woofers came with a rubberized compound all the around the 'W' shaped surround so repair with butylene wouldn't be out off order.

One question you'll want to decide is if you want to keep these as 'museum' piece examples in memory of their original owners or 'tart them up" with parts and modifications that will make them more hifi and better examples of the speakers of their day. Plenty of opportunities for new and better rabbit holes here.

Much appreciated!

I do have a tone generator, but surprisingly no amp in the house to try them with. All of our current speakers are powered monitors with built-in amps and no output for other speakers. I suppose I could crack them open and grab a feed off the amp but I found a cheap amp locally I should be able to get this week for testing the JBLs.

Do you have a suggested butylene treatment? So far haven't found direct links to anything, but RoyC's comments in this thread https://community.classicspeakerpage...oth-surrounds/ are interesting.

I suppose to answer the question of museum vs tarted-up... I'll have to see how they sound. If the D130s are sounding nice and the Wolverines are off I may try recapping the crossover. Have read of people enjoying the sound of them once repaired.

Thanks again for the info, much appreciated!

[milkshake]

You didn't ask value questions, but you're going to get those answers anyway! Good on you for wanting to play them.

My D130s date back to my Dad when I was but 5-years-old. And they're still playing strong. Your cabinets are about as small as they come for the D130, and that was on purpose for wife acceptance. I have the larger C35 and C37 and even with that volume the D130 is really not a capable woofer in the realm of today's music. It is an extremely pleasant speaker to listen to acoustic guitar, cello, and most orchestral recordings. And don't tell the Grateful Dead that it can't rock!

But your cabinets will cramp it and, at least within the past few years, the legs on your cabinets have been worth more than the entirety of the rest of the system. The D130 was actually sold as a full-range speaker without a tweeter as a basic system that could add the tweeter later. Without seeing your crossover wiring, it could be connected that way now. Or at least you'd have no problem hooking it up that way for testing/listening if there's a problem with the Wolverine setup.

Repairing a tear in a D130 cone can be easily accomplished by saturating some thin paper in a diluted glue (Elmer's, Aleene's) and patching from the rear where it won't be seen in front. Then enjoy them with some fully instrumented recordings. It's probably not worth the money to attempt to add the original JBL 075 tweeter and crossover they were normally paired with. You can buy entire new/used systems that will perform better for less than the cost of those components.

Have fun and keep them for what they are. I still have mine—as well as dozens of other JBL pairs. But the D130 is what got me started!

Great info, much appreciated! It's amazing to hear that these cabinets are considered small, with some of the modern speaker tech I've heard you can get quite full bass response from very small monitors these days -- just goes to show how much tech changes.

Re: crossover, it's definitely connected inside -- hi running to the tweeter and lo running to the D130. Once I have an amp in hand for testing I'll see if anything is still making sound, fingers crossed!

I believe once I get them running my first listen will be some Galt MacDermot records... seems like a good pairing. =) (Guessing most people here once they heard "DJ" imagined boring techno... not in our house!)

I also have a 12" of The Rolling Stones' "Miss You" remix that was done by Bob Clearmountain -- sounds VERY good, curious what the JBLs will sound like with that?

Appreciate all the info very much and hearing about your father's speakers!

I knew it was a good idea to sign up here =)