Jump to content

Can my speaker be repaired?


Recommended Posts

  • Members

To make a long story short, around 1966, I had planned to build my own high powered solid state guitar amp. That project never worked out, and I was left with 4 100 watt "life time guaranteed" Jensen musical instrument speakers. Fast forward about 40 years and I bought a Crate "Power Block" amp, and build two 2x12 speaker cabs for the amp. I think I used the setup less than 10 times. Forward several more years... Yesterday I used the speakers to test out a stereo amp I picked up at a surplus store, and I noticed that one of the cabs was lower in volume than the other. I tracked it down to one of the speakers, not being dead, but being considerably lower in volume than the others. Can that sort of speaker problem be repaired? The Jensen company today, isn't the same Jensen company of the 60's, so I'm sure the life time guarantee isn't going to help.

0031542950ffd47d768d49a69ec314de.thumb.jpg.3f5c048c23128d066c2bed537e3b06bf.jpg

a8cb717d02f620d798c61249692fdaac.jpg.a661cc5eb94daae1fe3300f76a9e8ff0.jpg

Link to comment
Share on other sites

  • Members

At what time in history did they start using that foam surround that would crap out after a couple decades? For starters assuming the wiring is good and there's no loose wires, remove a speaker and inspect the outer perimeter of the speaker cone. Is the foam at that interface decomposed? It can be repaired, and I'd bet a dollar that if that's the problem, then all four will need the same treatment. I've had speakers fixed this way at a pro's shop, and I've done it myself. One pro did a great job, another did a {censored}ty job, and I did a job as good as the pro's. Repairing it professionally probably won't be financially worth it. Since you appear to be a DIY guy and the foam is the culprit, I'd recommend searching out the proper foam replacement on eBay and glue them on yourself. The first one will be interesting, the other three will then be easy.

 

You must have a big garage to keep that kind of stuff around for so long. And you know, Lemmy used a busted cone on one of his speakers back in the day, and it worked out alright for him.

Link to comment
Share on other sites

  • Members

I live about a mile from GSS Speaker Repair Service in North Hollywood, CA. They re-coned my Advent Home stereo speakers, and my Jensen speaker in my Epiphone combo amp. I was happy with the job they did. I guess I'll go over there tomorrow and ask about it. BTW, they have rubber surrounds. I can get a new speaker for about $60, so it might not be worth repairing, on the other hand, I paid $50 each for these speakers in '66, so they are probably better.

Link to comment
Share on other sites

  • Members

I don't recall Jensen MI line ever using foam surrounds and I'm not sure I've ever seen a butyl surround on an MI Jensen either. Butyl is generally pretty stable, don't know about 40 years though. To replace a surround properly, the dust cap needs to be removed, the vc accurately shimmed and then once cured a new dust cap needs to be installed. Doing it any other way is half-assed so beware of the hacks out there.

Link to comment
Share on other sites

  • Members

Ya I was going to say. I think if it's the surround, it really means it needs a complete recone (hey stuff dries out after that many years). If they are really those vintage speakers, I'd guess they would have a pretty high resale value if they were reconed using factory spec stuff (somebody somewhere has the kits :-) so it might be worth it anyway.

Link to comment
Share on other sites

  • Members

Hey Jeff

 

Have you measured the resistance of the cabs to rule out any differences in the speakers themselves? Speakers usually don't fail and end up at a lesser volume. There may be nothing wrong. The speakers could be different and/or they could be wired differently.

Link to comment
Share on other sites

  • Members

It wasn't a wiring problem. I tested the speakers individually, and there was a dramatic difference in volume.

 

I also just got back from GSS where I left if for repair. The cone was frozen. The guy said it was due to a magnet shift. He offered to fix it "good as new" for $75. I figured it was better to fix a vintage Jensen speaker that cost me $50 nearly 50 years ago then buy a new $60 speaker.

 

BTW, I thought it had a rubber surround, but all I saw was paper.

Link to comment
Share on other sites

  • Members

Does he plan on fixing it without reconing it? Better get a guarantee and bounce it a few times once you get it back. I have shifted a few magnets in my days and you can do it without reckoning the speaker, but it's a crap shoot (and you can easily do it yourself)

Link to comment
Share on other sites

  • Members

I did bring up re-coning. I think he'll make that decision when he works on it. I reminded him that the cones were old, but in retrospect, I don't know if he thought I wanted to keep the nearly 50 year old original vintage paper, or if I was concerned about it being so old. I trust him to make the right decision. I'll have it back in about a week.

Link to comment
Share on other sites

  • Members

Shifted magnets (pole pieces) are impossible to repair properly (and reliably) without demagging the speaker, doing a lot of surface prep, using the proper adhesives, and then remagging the speaker. $75 is a bargain IMO.

 

I was pretty sure it wasn't a foam/butyl surround.

 

I would also be suspect of the remaining speakers, pole piece failure tends to run with manufacturing lots. Age can also be a factor. You fall into both catagories.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...