Is my orange label jbl speaker still good?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Legendofamind7, May 19, 2006.

  1. Legendofamind7

    Legendofamind7 Member

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    So in the search to find what was wrong with my 72 twin reverb my buddy said check the speakers. I pulled the grill cloth and everything looked okay but when I fired the amp up at a low volume I quickly realized that the one speaker wasn't playing anything. Of course it had to be my original orange label jbl speaker. The other one is a jbl k120 but that was replaced about 10 years ago and works fine. The speaker that isn't working looks fine, no tears or anything. So is it shot? Or does it just need a repair? I was looking to sell these anyways and get some webers (not a fan of jbl's) but now I'm hesitant to put the one up for sale if its not working. Any input would be great, thanks.
     
  2. Swarty

    Swarty Member

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    Both
     
  3. Legendofamind7

    Legendofamind7 Member

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    oh man bummer, do you recommend repairing then selling it or selling it as is. Like I said I don't plan on using these speakers anymore...
     
  4. Reeek

    Reeek Member

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    To the experts here, if it's not playing at all, wouldn't it show open on an Ohm meter?

    The last hi-fi speaker I blew (didn't make a sound) when I put the DMM on it, it showed no resistance at all.
     
  5. Swarty

    Swarty Member

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    The voice coil could be froze up, and it could still read correctly. FWI, a generic recone will typically cost around $60, a JBL parts recone will be about 3x that. You might just want to sell it as is... probably worth $75 or so blown ???
     
  6. drbob1

    drbob1 Silver Supporting Member

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    AFAIK there're no sources for orang lable JBL recone parts-they're long gone. Weber would have been a great choice to recone but now I'd probably recommend Orange County. It is a valuable speaker and you shouldn't have any trouble selling it as needing a recone. Do check that the problem isn't just the wiring. You can use a 9v battery to see if the voice coil moves just a bit (an old, tired one would be best).
     
  7. Swarty

    Swarty Member

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    My recommendation is www.circuitshop.com. They are in Grand Rapids, MI. They use current JBL parts and the speakers sound very legit... they've done many for me.
     
  8. Legendofamind7

    Legendofamind7 Member

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    dr bob could you explain the test using the battery? And how do I determine if its the coil or the cone? Thanks guys.
     
  9. rockon1

    rockon1 Member

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    Briefly touch a nine volt across the terminals. You should hear a slight pop AND see the cone move slightly too. This will tell you the voice coil is good and that it isnt froze up. A multimeter test will only tell you if the coil is in tact or not.
     
  10. Legendofamind7

    Legendofamind7 Member

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    Hey so I did the battery test and voice coil moved! So thats a good sign then huh? So it needs to be reconed and it'll be alright? What is an appropriate price to list this at knowing it needs to be reconed? Thanks for your help. :AOK
     
  11. rockon1

    rockon1 Member

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    Sounds like it should work actually. Perhaps you have a wiring problem ? Can you reverse the wiring putting the wires that go to the working speaker to it and vice versa?
     
  12. Legendofamind7

    Legendofamind7 Member

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    ya know I was thinking that maybe it was a wiring problem because the cone looks fine and now that I know its not the voice coil I was starting to wonder if it was the wires. The wires are the original ones from 35 yrs ago, where can I get new ones? Would just normal speaker wire from radio shack or somewhere work? Or should I get some professional wire? thanks for the help. Until then I'll switch the wires around and see if it works.
     
  13. Legendofamind7

    Legendofamind7 Member

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    hey so I hooked both the speakers up and the same thing happened. Then I reversed the wire and both speakers worked! It was just the wires, bad connection I guess. Thanks for your help.
     
  14. Legendofamind7

    Legendofamind7 Member

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    So I had a chance to play at louder volumes today and did some testing. The speaker worked but then it started to crackle. This mostly happened when I played bass notes on the upper strings. Then when I turned it up a little more it got worse, would cut out all together after crackling...if I played some more bass notes it would cut back in but would still crackle. Turn the volume down and it wasn't as bad, turn it down real low and it went away. I recut the wire to see if it was a bad connection but that didn't help it. So is this a bad cone?
     
  15. brad347

    brad347 Member

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    something is wrong with your wiring. Probably at the plug that goes into the speaker jack. I'd say start all over with new wire and a new plug before you fry your output transformer.
     
  16. Legendofamind7

    Legendofamind7 Member

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    Could I grab new wire/plug at the local guitar store? I'm not playing the amp right now because I don't want to damage it anything further. I just have turned it on to test the speaker out. thanks for the input.
     
  17. brad347

    brad347 Member

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    Probably, or you could make your own. Or you could go to www.hoffmanamps.com to get the necessary parts... he even has the correct Fender "F" plug. Regular lamp cord works fine for speaker cable in my experience, I get the biggest gauge Home Depot sells. Some people will argue this though, so do some research and form your own opinion. I will say I'm incredibly picky about everything down to picks and instrument cables and lamp cord is my favorite speaker wire for old Fender and Magnatone amps.
     
  18. Legendofamind7

    Legendofamind7 Member

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    I was tinkering with this mess some more and I don't think its the speaker cable that connects the two speakers to the amp. I came to this conclusion because I switched the wires that connect to the good speaker to the bad one and vice versa. Both times the good speaker works fine and the bad speaker performs as previously posted. I took the spring connection off the bad speakers +/- posts and wrapped the speaker wire around the metal ring of the +/- wires from the speaker. Once again the bad speaker did the same thing. So I'm thinking it must be something loose inside the original jbl that is causing it to crackle and cut out and not the spring posts outside the speaker either. And like I said it only happens when I hit the e/a/d strings which shakes the speaker more, therefore I think moving the loose connection inside the speaker and causing it to cut out. If I'm correct is there anyway to open this bad baby up and look at the connections? Or would I have to send it away to get fixed? Let me know if you concur and any advice you may have. Thanks
     
  19. SarasotaSlim

    SarasotaSlim Member

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    Listen carefully...

    You're getting very sleepy...

    ...very sleepy...

    ...you are asleep.

    ...now when you wake up you will pack up that old worthless problem causing JBL speaker and SEND IT TO ME!:Devil
     
  20. Legendofamind7

    Legendofamind7 Member

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    That's not a very helpful post slim, unless your proposing that you want to buy it?
     

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