JBL L100a's

[HoneyBadger9]

Greetings there everyone! So I came across one of the best deals I've gotten from a thrift store, or anywhere for that matter, some JBL L100a's for $25!! I didn't even spend any time looking for anything else, and purchased them and went straight home with them.

That being said, they do need some work. As far as I can tell from just a quick power on as well as testing each individual driver, both tweeters are dead, and one mid-range is dead. I was curious as to what my available options are to do. I've been looking at having the tweeters repaired at JAMAC, at $60 each, as well as I've seen some other threads on here that recommended getting these:

https://www.simplyspeakers.com/repl...6ePK4ey2vw84tDU3fXKoY5-EkOCmfyUxoCMTUQAvD_BwE

I was mostly curious as to what my best option might be and what might be the best way to restore these to their former glory. The other issue is the mid-range as I don't even know where to start there, so some places to start looking would be greatly appreciated.

I've also done some looking and found that someone designed a newer crossover for these, but that's something I'll do once I'm able to give these a listen with their, hopefully working, original crossovers.

Thanks for all the help in advance!

 

[Caryw]

I would get the original tweeters rebuilt and find a good mid on eBay or become a subscriber here and post a wtb in Bartertown. Then go to Huntley Audio for grill cloth. I just redid my 110’s . Did I see your post on Facebook? Was a good story about getting them home

 

[donprice]

Exercise the L-pad dials back and forth a few dozen times before you give up on the tweets and mid. You could just have a dead spot due to corrosion.

Lots of threads here on how to remove the foilcal (heat and thin spatula or similar) to access the crossover and remove drivers for repair/testing. They tend to get stuck after 40 years.

I would try to avoid replacement drivers if your goal is "restoration" and go with a recone. No experience with the SS replacement drivers or JAMAC's work.

Good luck!

 

[Nyjblbob]

I would also pull the mids and Tweeters out
And test them on their own
Show the actual model number of them
Some of the early ones are different

 

[R Swerdlow]

Exercise the L-pad dials back and forth a few dozen times before you give up on the tweets and mid. You could just have a dead spot due to corrosion.

Yes, exactly! Work those L-pads dials many times before giving up on the mids and tweets. Even if that never gets results, test those drivers individually with a 1.5V AA battery. In the L100a speakers I've seen, it was the L-pads that failed, not those drivers.

I would also pull the mids and Tweeters out and test them on their own

Pulling out those drivers can be hard in such old speakers. Instead of removing them, pull out the woofer, and you can easily get to the wires running from the crossover to the tweeter and mid drivers. It's easy to cut those wires and splice them after testing. It can be much harder to repair cosmetic damage that could happen as you try to remove the tweeter or mid from the front baffle.

For the revised crossover for the L100a, the link below has it as a downloadable PDF. (It avoids using those easily corroded variable L-pads.) The parts list was revised a year ago. What might be available now, and at what price, is anyone's guess.
JBL L100 crossover kit--Murphy or Troels Gravensens

 

[goodolpg]

I would also pull the mids and Tweeters out
And test them on their own
Show the actual model number of them
Some of the early ones are different

What he ^ said.
And if the midrange is faulty, either ebay for replacement driver(s) or MillerSound for repair.

 

[HoneyBadger9]

Did I see your post on Facebook? Was a good story about getting them homeView attachment 2534974

My dad was the one who posted it but I was the one who got them! It definitely was fun getting them home.

I would also pull the mids and Tweeters out
And test them on their own
Show the actual model number of them
Some of the early ones are different

So I pulled everything out and tested it all, and still no sound or anything coming from both tweeters, and one mid. So probably looking like a repair for the tweeters through JAMAC or MillerSound if they do it, as well as the mid though MillerSound.
The serial number on the tweeters are LE25, and the mids are LE5-2.

Once I get some time this weekend I'll pull out the crossovers and take a look at them to see if they need any work done or if anything needs to be replaced. Would it be recommended to just replace the caps regardless of shape, or wait until they die out and then go from there?

Thank you everyone for the replies!

 

[goodolpg]

I don't think MillerSound does tweeters.
AK'er GordonW might?