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L100t3 sounding very strange

Jasonbcox

Jasonbcox

New Member
Hi friends,
I recently picked up a pair of L100t3 with pretty severe sun damage. Took them apart, re-stained and lacquered the cabinets.drivers were already re-foamed; I did the tweeters. Put them back together and the left speaker sounds terrible. Initially I thought maybe the mid or the tweeter was disconnected, because it was just lacking a lot in vocals and overall sounds like it’s playing inside a metal garbage can. Maybe a tunnel.

Checked all the wires , everything is connected properly and making good contact. Switched the wires , the issue stays with the speaker. The right speaker sounds superb, the left … awful. Did I manage to damage something while they were in pieces? I can’t see where I did that, but I must have done something. Is it possible that the crossover on that side needs rebuilt , even though the other sounds great?

Thanks for reading and thanks for your thoughts.
 
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What I would do is move the right speaker drivers and testing for sound issues after each driver is installed into the left speaker. If the distortion goes away then it is a driver(s) problem . If it stays with the left speaker then it is crossover problem.
 
OldJBL said:
What I would do is move the right speaker drivers and testing for sound issues after each driver is installed into the left speaker. If the distortion goes away then it is a driver(s) problem . If it stays with the left speaker then it is crossover problem.
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That’s smart, thanks. Didn’t think of that. Let’s say it is a crossover problem - would recapping be the place to start ?
 
I am not all that knowledgeable when it comes to electronics but changing the capacitors would be a good place to start. If that doesn't work then replace the rest of the components. After doing this you might find that doing the same for the right crossover is necessary to balance the sound between the two speakers.

I am the original owner of a pair of L100t3s and still use them daily. They are a good sounding speaker when working well but the Lx series from the 1990s are my personal favorites.
 
IMG_5776.jpegSo, as you suggested I swapped the tweeters from one side to the other and that is the problem. It just appears to be not working at all. I cleaned it all out, scraped the old foam coff, put it back together, nothing. Not sure why it’s dead, looks the same as the other one.
 
How would I tell if it’s working correctly outside of volt meter testing?
 

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Jasonbcox said:
So, as you suggested I swapped the tweeters from one side to the other and that is the problem. It just appears to be not working at all. I cleaned it all out, scraped the old foam coff, put it back together, nothing. Not sure why it’s dead, looks the same as the other one.
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The 035tia tweeter's Achille's heal are the leads from the terminal to the coil. I have broken them just from detaching and/or reconnecting the speaker wires. Check for continuity between the leads, and if there is continuity, check the resistance value against what is spec'ed (4.0 ohms). Also, keep in mind if you have one shipped to you and it is not packed well it can be damaged.

I have used the replica 035tia tweeter from Simply Speakers and found them to be very, very close, if not identical sounding, as the OEM part. I used them in a pair of L20t3s and couldn't tell a difference from the OEM tweeter. If you do use them there is be a polarity issue with connecting the speaker leads on the t3 speakers. This is due to the older 035ti version having the leads reversed compared to the 035tia versions. The SS tweeters are set up to match the 035ti tweeters. I hobbled together a connection using a zip tie for the spade connectors and opened up the female connector so it slid over the female connector on the tweeter. I was going to do it right when the zip ties failed but they are still holding.

1000007557.jpg
 
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Fantastic info, thanks. I was looking at those replacements but they are out of stock. Looks like Midwest Speaker Supply has the same thing
Here
 
Jasonbcox said:
Fantastic info, thanks. I was looking at those replacements but they are out of stock. Looks like Midwest Speaker Supply has the same thing
Here
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I would buy them again without hesitation. They are well built, the screens are much better than the OEM tweeter, they have new foam and even have the plug under the dome like the OEM tweeters. A big plus is that I don't have to worry about a used tweeter being damaged during shipping. I am sure that the Midwest tweeters are from the same manufacturer.
 
To be accurate however, the SS replacements for the D8R035Tia are actually more like the D8R035Ti as the major performace-related difference was the copper-clad aluminum coil on the Tia to reduce moving mass. The SS ones are copper like the Ti. I also don't know if SS's supplier duplicated the material-thickness and forming control that JBL's supplier did, nor whether they have the pin-prick hole of the late 035Ti (running change) and 035Tia dome.

However, it is the only option at this point, just throwing (likely useless) information out there for those who care.

Finding a good used 035Ti and replacing the damping foam in both would be my preference. I hoarded the D8R035Tia kits for a while but never needed them, long gone (but still have a pair of L20Ts somewhere around here). I think that the OE kit does show up occasionally, rarely, and the used tweeter is overpriced (IMO) but maybe you can buy a pair of needy L20Ts and harvest the tweeters.
 
Well, it was one of the tweeters. So I have replaced the pair with the repro tweeters from Midwest Speaker. Seems to have really improved things. Now considering a recap as well, just because they are old. Thoughts?
 
Jasonbcox said:
Well, it was one of the tweeters. So I have replaced the pair with the repro tweeters from Midwest Speaker. Seems to have really improved things. Now considering a recap as well, just because they are old. Thoughts?
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I have thought about re-capping mine ever so often but I don't think I hear much of a difference in them from when they were new. Now this might be because the change in sound quality might have occurred too slowly for me to perceive. I did inspect the crossovers a couple of years ago and, visually, they looked the same as they did when new. This said, I like the sound I get from them now so I just decided that I will just keep them as they are.

Did you have to reverse the polarity with the leads to get them to sound right?
 
Jasonbcox said:
Well, it was one of the tweeters. So I have replaced the pair with the repro tweeters from Midwest Speaker. Seems to have really improved things. Now considering a recap as well, just because they are old. Thoughts?
Click to expand...
I've measured the capacitors with basic tools on a JBL made in the same era. Just something that was done out of curiosity while they were completely disassembled. These were blue caps labeled "Culver" and each one had a bypass cap. The esr and capacitance looked good. The matching between the two crossovers looked very good. That was probably in 2019.
 
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