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JBL L46


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NOT "Classic New England Speakers" I know but I haven't gone over to the Dark Side ;)

A friend's brother asked if I could repair them because "the woofer on one of them blew out." I figured it was the surround and told him to send them my way.

I'd never worked on JBLs before and found some surprises: They're nice looking, with real walnut veneer. The tweeter is covered with a mesh dome. Woofers are very substantial cast aluminum frames. Nice. Ported of course. Dimensions are 20.5" x 12.5" x 10.5". Smaller than an AR-2ax, about the size of a Dynaco A-25.

The L46 appears in a 1982 JBL brochure. Because the NPE capacitors are over 30 years old I decided to replace them with film. Each xo has two 14uF caps and one 7uF. In addition there are 0.0038 film bypass caps on 2 of the NPEs (according to the brochure; "The network makes use of polypropylene bypass capacitors for better resolution of complex transient waveforms, and therefore clearer, more accurate sound." I doubt it but I left the bypass caps in place. YMMV). I replaced the NPEs with caps I had on hand: A Madisound "surplus" 10uF + two "surplus" 2uF caps for one of the 14s, a 10uF surplus plus a Dayton 4uF for the other and a Carli 6.8uF + a Nichicon 0.2 for the 7. Side note: I really like the surplus 10uF caps but the surplus 2uF caps have maddeningly short leads! No mistaking polarity on JBL drivers. The + terminal is male and the - is female (or maybe the other way around, but you can't make a mistake!).

Got new surrounds from John at MSound. He's no longer on ebay but can be reached at msound@shentel.net. Also bought new dust caps and the "trim" external gaskets. The surrounds are rear-mounted to the cones. I'd encountered that before with Advents and it wasn't too difficult. I did try front-mounting first but it just looks better rear-mounted with the white cones (again from the brochure "the woofer cone is coated with Aquaplas, an exclusive formulation which creates a laminated construction with ideal damping characteristics").

First surprise: TWO dust caps! Roy said this is not unique but I'd never seen it before. I cut the inner cap and hinged it back for shimming, then glued it back in place when finished. The outer dust caps I ordered were the same diameter as the originals, which was a mistake on my part but I just trimmed the originals as close as possible, glued the new ones on and later filled in around the flange with white glue to give a smooth transition.

Roy says all those clamps were not needed. Makes sense. I was just following some old MSound instructions but the glue (Aleene's Tacky) really grabs well.

The cabinets had been well taken care of but there were a couple of whitish scuff marks and the wood was kind of dry so I first wiped them down with Howard Restore-a-Finish, rubbing the white marks with some steel wool. The next day I applied a coat of Minwax Antique Oil followed by a second coat the following day.

Put them back together and fired one up. UGH! Is this the "West Coast sound?" All bass an no highs. Oh wait--time to get out the ol' stethoscope and listen to the tweeter. Duh. Dead tweeter. I pulled it out and did a couple of tests to be sure. Yup. One good tweet, one bad. These tweeters can be rebuilt but JBL no longer has the diaphragms and after-market ones from Simply Speakers are $25 so I just bought a second-hand JBL 034 tweeter on ebay.

NOW let's give a listen. Very nice. I have not done an A/B comparison with my AR-3a's but these are nice speakers (when the tweeters are working) :lol:

Total cost of the restoration was about $70. Not bad. A few pics attached.

-Kent

post-101828-0-61442300-1431726090_thumb.

post-101828-0-86676800-1431726100_thumb.

post-101828-0-72812700-1431726110_thumb.

post-101828-0-31228700-1431726130_thumb.

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Follow-up:

Very nice, with good build quality but they won't be replacing my ARs. They seem quite bright, even to my old ears.

Found a write-up here, which is pretty consistent with my observations: http://www.audiokarma.org/forums/showthread.php?t=134980

AK member thedelihaus wrote;

"I loved them for this. Drum and bass, techno, hip-hop, heavy metal, and many other flavours of music are embraced by these dynamos. But put them on a diet of jazz, or female vocals, or male vocals, acoustic, or folk, and the JBLs are not my cup of tea."

Since I never listen to techno, hip-hop or heavy metal I can't comment on that but I agree these do not excel with the music I listen to most: Jazz, "classic" rock, acoustic and classical. The AR-3a OTOH does very well with all of those.

The JBLs are very very nice but as thedelihaus wrote, just not "my cup of tea."

YMMV

-Kent

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I was shopping at a community garage sale last weekend and found a pair of JBL Studio Monitor 4410's for $5. I couldn't resist. All the drivers work but the woofers need foam. The mids and tweeters on these each have a pot for level control (I wish the pots on my 3's worked this well) so I should be able to get a good balance. I plan on selling them but I'm gonna drive them first. I'll be working on these alongside a pair of 3a's I acquired 3 weeks ago (the 3a's are staying!)

Jeff

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Nice write-up, Kent. I enjoyed reading about this project, and as usual, you did a really nice job with those crossovers - - I take it that the x-o panels were easily removed with four screws? I know very little about the extensive JBL line-up of speaker models, but I find it interesting that the product literature actually mentioned the bypass caps. Apparently, this was not an uncommon component found in many JBL's of a certain vintage, and I know there are an equal number of believers and detractors when it comes to this issue of bypass caps. I have to believe that JBL engineers had a strong rationale for adhering to this practice, but since I've never tried it, perhaps that explains why I am still tinkering to resolve the "complex transient waveforms" bouncing around my living room :P .

Full disclosure: even though I tend to be firmly planted among the 'east coast' speaker brethren, I, too, have come into possession of a pair of JBL's needing not very much work in order to re-furb them. Different model, but likewise, I'll probably replace the caps and I need one replacement tweeter (LE-25). Mine are the popular L-100's, and I certainly couldn't pass them up since I was getting change back from my Hamilton, but my biggest decision will probably be whether or not to purchase/fabricate a pair of the iconic waffle foam grilles. If I do, it will not be the orange or brown - - no, no! - - - but definitely the vibrant blue.

post-112624-0-47025500-1432688360_thumb.

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Thanks Robert

Yes--the xo boards came out simply, fastened with just 4 screws and no adhesive.

Here's a source for your grilles: http://www.foamspeakergrilles.com/

The L100s are legendary--a worthy project. Here's a brief write-up http://www.vintage-speaker-review.com/2012/02/jbl-l-100.html

Good luck and be sure to post pics!
-Kent

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  • 11 months later...

Hello JKent,  Could you please break down a part of your repair for someone with no experience changing caps/film(?)/etc.  I don't even have a soldering iron yet.  I'm not even sure where to buy the materials to fix my JBL L46. Based on the picture you included I'm guessing that the left is before and the right is the after.  (Correct?)  I re-foamed the pair after purchasing them 3 months ago and they have sounded wonderful, but this week, the right woofer has crapped out (rumble/rattle/or nothing) and my troubleshooting process has led me past my comfort level and into the realm of...things that may need to be replaced and soldered.    Any guidance/detailed breakdown of your repair description below would be much appreciated.    

Many thanks,

Gregg

 

The L46 appears in a 1982 JBL brochure. Because the NPE capacitors are over 30 years old I decided to replace them with film. Each xo has two 14uF caps and one 7uF. In addition there are 0.0038 film bypass caps on 2 of the NPEs (according to the brochure; "The network makes use of polypropylene bypass capacitors for better resolution of complex transient waveforms, and therefore clearer, more accurate sound." I doubt it but I left the bypass caps in place. YMMV). I replaced the NPEs with caps I had on hand: A Madisound "surplus" 10uF + two "surplus" 2uF caps for one of the 14s, a 10uF surplus plus a Dayton 4uF for the other and a Carli 6.8uF + a Nichicon 0.2 for the 7. Side note: I really like the surplus 10uF caps but the surplus 2uF caps have maddeningly short leads! No mistaking polarity on JBL drivers. The + terminal is male and the - is female (or maybe the other way around, but you can't make a mistake!).

 

 

 

                                                                                                                                  

 

 

 

 

 

                                                                                                                          crossover (3).JPG

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  • 3 years later...

Been a long time JBL guy from late seventies. My greatest failure was selling a mint pair of 4311b....stupid. Anyway, I purchased a pair of L46 that looks like museum pieces . No marks, pristine grills. The woofers were re-foamed by a guy in Utah that worked for JBL in their hay days. Perfection. 
 

 Was very surprised to hear the quality of their sound. I have been playing with a a pair of L3 that I assumed would be far superior. Nope. I loved the series with the white Aquaplas when I was young and poor. I really miss the old JBL. I have switched to RBH reference for my theatre, but these little guys will be my two channel for a while. 

E5328B02-EF55-44EA-AAE0-267883C3949A.jpeg

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  • 1 year later...
On 5/15/2015 at 2:48 PM, JKent said:

NOT "Classic New England Speakers" I know but I haven't gone over to the Dark Side ;)

A friend's brother asked if I could repair them because "the woofer on one of them blew out." I figured it was the surround and told him to send them my way.

I'd never worked on JBLs before and found some surprises: They're nice looking, with real walnut veneer. The tweeter is covered with a mesh dome. Woofers are very substantial cast aluminum frames. Nice. Ported of course. Dimensions are 20.5" x 12.5" x 10.5". Smaller than an AR-2ax, about the size of a Dynaco A-25.

The L46 appears in a 1982 JBL brochure. Because the NPE capacitors are over 30 years old I decided to replace them with film. Each xo has two 14uF caps and one 7uF. In addition there are 0.0038 film bypass caps on 2 of the NPEs (according to the brochure; "The network makes use of polypropylene bypass capacitors for better resolution of complex transient waveforms, and therefore clearer, more accurate sound." I doubt it but I left the bypass caps in place. YMMV). I replaced the NPEs with caps I had on hand: A Madisound "surplus" 10uF + two "surplus" 2uF caps for one of the 14s, a 10uF surplus plus a Dayton 4uF for the other and a Carli 6.8uF + a Nichicon 0.2 for the 7. Side note: I really like the surplus 10uF caps but the surplus 2uF caps have maddeningly short leads! No mistaking polarity on JBL drivers. The + terminal is male and the - is female (or maybe the other way around, but you can't make a mistake!).

Got new surrounds from John at MSound. He's no longer on ebay but can be reached at msound@shentel.net. Also bought new dust caps and the "trim" external gaskets. The surrounds are rear-mounted to the cones. I'd encountered that before with Advents and it wasn't too difficult. I did try front-mounting first but it just looks better rear-mounted with the white cones (again from the brochure "the woofer cone is coated with Aquaplas, an exclusive formulation which creates a laminated construction with ideal damping characteristics").

First surprise: TWO dust caps! Roy said this is not unique but I'd never seen it before. I cut the inner cap and hinged it back for shimming, then glued it back in place when finished. The outer dust caps I ordered were the same diameter as the originals, which was a mistake on my part but I just trimmed the originals as close as possible, glued the new ones on and later filled in around the flange with white glue to give a smooth transition.

Roy says all those clamps were not needed. Makes sense. I was just following some old MSound instructions but the glue (Aleene's Tacky) really grabs well.

The cabinets had been well taken care of but there were a couple of whitish scuff marks and the wood was kind of dry so I first wiped them down with Howard Restore-a-Finish, rubbing the white marks with some steel wool. The next day I applied a coat of Minwax Antique Oil followed by a second coat the following day.

Put them back together and fired one up. UGH! Is this the "West Coast sound?" All bass an no highs. Oh wait--time to get out the ol' stethoscope and listen to the tweeter. Duh. Dead tweeter. I pulled it out and did a couple of tests to be sure. Yup. One good tweet, one bad. These tweeters can be rebuilt but JBL no longer has the diaphragms and after-market ones from Simply Speakers are $25 so I just bought a second-hand JBL 034 tweeter on ebay.

NOW let's give a listen. Very nice. I have not done an A/B comparison with my AR-3a's but these are nice speakers (when the tweeters are working) :lol:

Total cost of the restoration was about $70. Not bad. A few pics attached.

-Kent

post-101828-0-61442300-1431726090_thumb.

post-101828-0-86676800-1431726100_thumb.

post-101828-0-72812700-1431726110_thumb.

post-101828-0-31228700-1431726130_thumb.

 

Hello, music lovers...I'm waiting on 2 clean sets of speakers due in next  week.....JBL. L46. and Boston A60s...to go witfh my Pioneer SA8500 Amp....Will be interesting to hear the differences....

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