• Please note that Audiokarma will be offline briefly for updates early on Monday morning, September 28th.

JBL L80T Project -- Gone Wrong

Zonker92 said:
Yup; the classic "does not affect sound" claim seen daily on eBay and Craigslist. :D



I have nothing concrete, but the dome shape is there for a reason; I suspect the dispersion pattern is substantially worse and very uneven.
Click to expand...


That is the correct answer!!:yes:
 
juniorJBL said:
That is the correct answer!!:yes:
Click to expand...

I suppose I really couldn't tell that the imaging was off since the speakers are set up now in the garage for testing and refurb. Since there is so much stuff in there and they are just up on a shelf against the wall nothing tends to sound its best.

The woofers appear to have been incorrectly refoamed at some point so it will be interesting to see how they look after I take them off and correctly put the new foam on the back of the cone.

Here are a few pics of them. You can see how beat up the drivers were. Almost like someone intentionally tried to destroy them for the hell of it.
 

Attachments

  • P1020879-r.jpg
    P1020879-r.jpg
    55.8 KB · Views: 69
  • P1020880-r.jpg
    P1020880-r.jpg
    65.4 KB · Views: 65
  • P1020882-r.jpg
    P1020882-r.jpg
    91.5 KB · Views: 59
  • P1020881-r.jpg
    P1020881-r.jpg
    86.9 KB · Views: 64
  • P1020886-r.jpg
    P1020886-r.jpg
    70.9 KB · Views: 50
if the dust caps remained on, and the spider was not removed, how did a foreign object get into the gap?

my guess is 1) the tolerances within the gap are VERY tight, and 2) the former may have been "tweaked" when trying to scrape the glue off the cone.
 
Hi everyone! - I have a chance to pick a pristine pair of L80 for half the price I was going to pay for L100 Century ( in line version )... anyone have any experience in comparing them both ? is L100 worth the extra ? any help would be appreciated!

Thanks
 
that's very surprising! considering I can have them for about £150 ( $240 ) where the cheapest L100 I could find ( the only I could find in UK ) are £300... wish I could live in US... much more to pick from -.-

anyway, thanks for help - much appreciated
 
I know this is a old thread, (maybe someone is looking for the same answers?)but what about a heat gun, held far enough away to keep from scorching but enough to just warm up the glue???(for spider removing that is)
 
jbl rebuild

You obviously have the smarts as to how the speakers work so you are way ahead of the game.
Try anything that is reasonable. I don't know about cutting stuff open.

Good luck

Paul
 
pkracing said:
I know this is a old thread, (maybe someone is looking for the same answers?)but what about a heat gun, held far enough away to keep from scorching but enough to just warm up the glue???(for spider removing that is)
Click to expand...

Most spider glue that I've seen is designed to be heat resistant/tolerant.
 
Hey Zonker,

What part of your 035TI ended up broken? Depending on what is broken they may be repairable, I recently repaired one of the 3 broken ones I had which I thought were toast. It was literally in piece parts, I had to unwind one loop of coil and resolder a lead, reshape the voice coile and then reglue the voice coil on the diaphram, center and glue the top plate back on the magnet, then reassemble it all. I now have one pair of working L20T again, one 035TI I might be able to repair, and one that is dead (the VC got pinched and completely folded and destroyed when I tried to pull it out)
 
I think on mine, the connection is broken somewhere in the flat space between the VC and the terminal. It's so damn tiny I can't even see the broken wire. I actually have three of them broken that way! :eek:

I should try your fix; thanks for the idea!
 
Yea, I don't remember where I read about unwinding a loop, but when I tried, it did not appreciably change it's resistance, and gives enough slack to attach it directly to the terminal. Good luck!
 
I was thumbing through this old thread tonight and had forgotten I had read and responded to it while restoring my own set of L80Ts. Mine made it back from the dead and are still in service here today, literally right now playing Guns and Roses. Great rock and roll speakers. Have them set up with an Accuphase E-202 sharing time with ADS L810s based on what I am listening too at any given time. Would love to run across another set some day, but up to now I have only seen the lesser JBLs at the thrifts. Would also love to stumble across a set of L7s but that may be wishful thinking as well.
 
I was able to get the spider off on one of my L166's. Took a LOT of patience with a dull Xacto knife to slowly pry the fabric away from the glue. don't rush anything, one thread at a time. BTW, I tried all sorts of solvents, but can't remember if any of them helped or which one did if any.

When I was refoaming it I thought there was something wrong so I immediately tried it out before the glue dried on the frame, so I was able to reuse the foam once it was repaired by lifting it off the frame till the glue dried. I used some foam blocks wedged in to hold the cone forward till it was safe to let it sit down again.

The voice coil had one turn at the very back that had come loose and was sticking out and hitting the rear plate. I was able to desolder the wire at the tinsel lead grommet, then unwound the loose bit and feed the wire to where it needed to go before cutting it off. To resolder you need to scrape the varnish off with a nail file or dullish blade.

One turn short does not seem to matter much...

So what was the final outcome?
 
Hey Zonker, I just wanted to confirm that the two L80T woofer you sold me were these two, and they did not, or at least one, did not get repaired in terms of the VC rub, right?
 
Man, I don't even remember selling them to you, Bart. But those were the only extra ones I had, so they must be. I recall refoaming them and one of them made a funny noise. A little tiny squeak.

It wasn't the voice coil. I think it might have been the damping material or adhesive. I cut into the cone accidentally trying to remove the dust cap. Then I stopped and gave up. So it still has a cut in the cone, plus the squeak.
 
Last edited:
Hi Zonker92, I am impressed with the work you did on restoring your JBL L80s. I have a pair of JBL L80s that I bought new back in the early 80s. I re-coned the woofers a few years ago and now I want to restore the veneer finish (faded but in good shape except for a couple small chips) and I want to replace the missing grill covers. How did you go about repairing small chips in the veneer and what process/products did you use to refinish your L80 cabinets? Also, any advice on how to replace missing grill covers would be appreciated.
 
You must log in or register to reply here.
Back
Top Bottom