Roadside JBL L100t Pair

[crybdr]

Greetings all,

I was driving along and saw a pair of speakers on the curb ready to be picked up as trash with a bunch of other refuse. I was looking for a speaker project and grabbed them mainly for the cabinets. They were WAY heavier than I thought (hurt back).

Anyway, after getting them in the garage I noticed that both woofers foam surrounds were completely gone (cones only supported by spiders). The midrange speakers looked intact. One tweeter was in good shape - the other looked like someone hit it with a hammer as the screen had contacted the titanium dome and put a concave dent in it.

Then I looked up what these things were JBL L100t and their quality and decided to see if I could at least test them as configured. Hooked them up and played really low volume - all drivers made noise and could feel woofer cones moving.

Okay. Then I decide I'll try replacing the foam on the woofers. Did meticulous prep and research and got that to work without a hitch. Used a tone generator (30 hz ) as I was doing final gluing to frame to check for voice coil centering. By the end of the glue up, I could drive the cones fairly far with no rub - holding them in the air while running they were completely silent. Success!! X2

Put everything back together and WOW!!! I don't hear anything wrong with the dented tweeter either. They drive hard and sound amazing.

So here is my question, looking for advice anyone would give. I can do some things to help make these even better. Just trying to figure the order and impact and balance that.

1. Refinish the cabinets (sand, fill and refinish veneer). They have stains, dents, and some chipped edges. Am a woodworker so this is pretty straightforward. They look fine for now.
2. Replace capacitors in v1 crossover -or- rebuild the crossover into what I read as a v3 crossover
3. Buy a new tweeter to replace the dented one
4. Fashion some kind of screen/cover to protect drivers.
5. Anything else?

It was a rare find for me and I learned a lot. They are a little big for my wife's taste but if they get finished and oiled up nice she may change her tune.

Sorry long read. Would really appreciate advice here if anyone has time / cares to share. Thanks in advance.

 

[OldJBL]

That is a nice score! I am the original owner of a pair of L100t3s which is the successor to the L100Ts. Adding a t3 design crossover will make a noticeable improvement to their sound quality. I think there is a vent tube modification that goes along with the crossover swap. The woofers in these speakers are well respected in JBL circles.

 

[crybdr]

Didn't know about the vent change but that's a good note. Thanks.

That re-foam job was tenuous all the way through. The cones have debris/dust/spider poop all over them. Started cleaning in one spot with some light rubbing alcohol and it seemed like it was making it worse. So abandoned that. Brushed them off as well as I could but they are still visually messy - shouldn't affect sound.

There was also a 1/2" tear on the edge of one cone. Spent some time with a jewelers loupe and some diluted Aileen's Tacky Glue to nudge that seam back together. Added a layer of coffee filter paper on the back to add a little more structure. There is about 1mm of shape wobble/distortion in that area of the circle but the foam seems to bridge that just fine.

 

[OldJBL]

They are worth saving. You can always re-cone them later if you like. If you do replace the veneer, look onto using walnut. To see what this looks like find some photos of the t3 versions because most of them were done with walnut. IMO, walnut has a nice, darker, richer finish than oak. Also, an option for replacing the tweeter is ones from Simply Speakers or Midwest Speaker. These tweeters are very good copies of the originals with more substantial screens. I have used them in a pair of L20T and L20t3 speakers and they sound great. The OEM tweeters have a rubber plug and foam under the titanium dome that degrades over time. The replacement tweeters also have this too. IMO, if there is any difference in the sound between the OEM and replacements it is due to the replacements having new plugs and foam which makes them a little less bright. Over time, the OEM tweeter can get a little brighter but this is a very subtle change and isn't easy for most people to detect.

 

[grey]

That is a nice score! I am the original owner of a pair of L100t3s which is the successor to the L100Ts. Adding a t3 design crossover will make a noticeable improvement to their sound quality. I think there is a vent tube modification that goes along with the crossover swap. The woofers in these speakers are well respected in JBL circles.

My take on the t3 is that it was everything that a modernized L100 should be. They do sound completely different and in a good way for my preference. The woofer was also deployed in the 4425 monitor and XPL-200.

 

[OldJBL]

My take on the t3 is that it was everything that a modernized L100 should be. They do sound completely different and in a good way for my preference. The woofer was also deployed in the 4425 monitor and XPL-200.

I owned a pair of L80T and L80t3 speakers at the same time and was able to do a direct comparison between them. The t3 version had much better midrange and highs that were less bright the the T version. The sound was more refined. There wasn't much difference in the bass, if any. I also have T and t3 variants of the L20 and like the L20T better. I think the reason is due to the bass port being located in the front (the t3's is in the rear) which gives more fullness to the bass and lower midrange and the L20t3 sound quality is much more dependent on speaker placement.

 

[kirk57]

3. Buy a new tweeter to replace the dented one

Often it is possible to disasemble the tweeter (removing the dome and attached voice coil from the magnet assembly) and push dents out from the backside.

 

[crybdr]

Often it is possible to disasemble the tweeter (removing the dome and attached voice coil from the magnet assembly) and push dents out from the backside.

I've seen a video showing the disassembly / reassembly of these. It's a pretty big dent though. Eeeek.

 

[ernieS]

Greetings all,

I was driving along and saw a pair of speakers on the curb ready to be picked up as trash with a bunch of other refuse. I was looking for a speaker project and grabbed them mainly for the cabinets. They were WAY heavier than I thought (hurt back).

Anyway, after getting them in the garage I noticed that both woofers foam surrounds were completely gone (cones only supported by spiders). The midrange speakers looked intact. One tweeter was in good shape - the other looked like someone hit it with a hammer as the screen had contacted the titanium dome and put a concave dent in it.

Then I looked up what these things were JBL L100t and their quality and decided to see if I could at least test them as configured. Hooked them up and played really low volume - all drivers made noise and could feel woofer cones moving.

Okay. Then I decide I'll try replacing the foam on the woofers. Did meticulous prep and research and got that to work without a hitch. Used a tone generator (30 hz ) as I was doing final gluing to frame to check for voice coil centering. By the end of the glue up, I could drive the cones fairly far with no rub - holding them in the air while running they were completely silent. Success!! X2

Put everything back together and WOW!!! I don't hear anything wrong with the dented tweeter either. They drive hard and sound amazing.

So here is my question, looking for advice anyone would give. I can do some things to help make these even better. Just trying to figure the order and impact and balance that.

1. Refinish the cabinets (sand, fill and refinish veneer). They have stains, dents, and some chipped edges. Am a woodworker so this is pretty straightforward. They look fine for now.
2. Replace capacitors in v1 crossover -or- rebuild the crossover into what I read as a v3 crossover
3. Buy a new tweeter to replace the dented one
4. Fashion some kind of screen/cover to protect drivers.
5. Anything else?

It was a rare find for me and I learned a lot. They are a little big for my wife's taste but if they get finished and oiled up nice she may change her tune.

Sorry long read. Would really appreciate advice here if anyone has time / cares to share. Thanks in advance.

Get yourself some Mahoneys wax off Amazon. There’s no finer product for JBL oiled cabinets.

 

[kirk57]

I've seen a video showing the disassembly / reassembly of these. It's a pretty big dent though. Eeeek.

You can do it!

 

[crybdr]

Get yourself some Mahoneys wax off Amazon. There’s no finer product for JBL oiled cabinets.

I really like the look of these. Might be a tad shiny for my taste, but I could see using this stuff on other wood projects here in the shop it if proved to be too much. Might just get some anyway to try.

There are drink rings, deep scratches, and chips in my veneer.

Did you sand yours before applying your wax, or just use it as a 'refresher' finish?

I was thinking of filling small spots with a good stainable walnut match wood filler, using 220 grit and just going SLOW to get the imperfections out without going through the veneer and then applying finish.

 

[ernieS]

I really like the look of these. Might be a tad shiny for my taste, but I could see using this stuff on other wood projects here in the shop it if proved to be too much. Might just get some anyway to try.

There are drink rings, deep scratches, and chips in my veneer.

Did you sand yours before applying your wax, or just use it as a 'refresher' finish?

I was thinking of filling small spots with a good stainable walnut match wood filler, using 220 grit and just going SLOW to get the imperfections out without going through the veneer and then applying finish.

I use Mahoney’s walnut oil by the gallon. I use 240 up to 1000 grit disks. Sanding with oil works the moisture in while avoiding dust. Let’s you work in the home. I’ve been able to remove some remarkable amounts of damage using this method. After using the wax (most photos taken while wet), let sit 24 hours, buff them with paper towel or cloth. You end up with beautiful color, warm glow. Flat finish. I’ve turned wood for 45 years. It’s all I use.

 

[hjames]

I've used Howards Feed'n'Wax or Howards Orange oil on my JBL cabinets. (I have gotten it from Home Depot)
This shows the difference between treated and untreated wood on a pair of
JBL L100T speakers I was refurbing in 2016.

I did get some Walnut oil from an online vendor couple years ago. Its more expensive and not sure its any better than the orange oil.

One of the folks here has done upgrades from the L100T to L100T3 crossovers. The change removes some of the harshness of the ti Tweeter
and moves the lower woof-mid crossover point as well. Its a worthwhile improvement.




Here is an oiled vs dry comparison from a pair I had in 2009. They are less shiny once the oil has a week or 2 to soak in.

 

[ernieS]

I've used Howards Feed'n'Wax or Howards Orange oil on my JBL cabinets. (I have gotten it from Home Depot)
This shows the difference between treated and untreated wood on a pair of
JBL L100T speakers I was refurbing in 2016.

I did get some Walnut oil from an online vendor couple years ago. Its more expensive and not sure its any better than the orange oil.


View attachment 3680493

Here is an oiled vs dry comparison from a pair I had in 2009. They are less shiney once the oil has a week or 2 to soak in.

View attachment 3680495

Beautiful work man.

 

[hjames]

Beautiful work man.

Uh, woman ...
But finding a pair of them curbside - wow, what a killer deal!
The JBL 2214 woofers are some of the best JBL made in that era -
- they punch WAY above their weight!

The current speakers in my multimedia system are 2 pairs of UREI 809A speakers using those
same 2214 woofers as the basis for their coaxial drivers.

Here is a comparison of the original JBL 2214s and the UREI Coaxials


The UREIs use the same foam and the same technique when replacing bad foam surrounds.



Here's a shot of the Multimedia room - UREI 809As as front and side surrounds, a JBL B460 18" subwoofer in the right front.
I've got a pair of DCM TimeFrame 600s as rear surrounds (not visible in this pic) for 7.1 sound.

 

[ernieS]

Both my L100t and 4425 slam because of that wonderful woofer. Interesting how deep the driver is compared to another terrific woofer from my L150a.

 

[crybdr]

I've used Howards Feed'n'Wax or Howards Orange oil on my JBL cabinets. (I have gotten it from Home Depot)
This shows the difference between treated and untreated wood on a pair of
JBL L100T speakers I was refurbing in 2016.

I did get some Walnut oil from an online vendor couple years ago. Its more expensive and not sure its any better than the orange oil.

One of the folks here has done upgrades from the L100T to L100T3 crossovers. The change removes some of the harshness of the ti Tweeter
and moves the lower woof-mid crossover point as well. Its a worthwhile improvement.


View attachment 3680493

Here is an oiled vs dry comparison from a pair I had in 2009. They are less shiny once the oil has a week or 2 to soak in.

View attachment 3680495

Those look great. I've used Danish Oil (not quite the same) on some oak furniture made in the past and it was pretty forgiving stuff, this seems similar.

Thanks for the tip on the crossover 1 > 3 conversion. I was able to find the schematics and have a few electrical engineers where I work who are interested in taking a look and giving me a hand sourcing parts.

 

[stereofanboy]

Be careful when sanding. I've heard that the veneer on this series is thinner compared to older JBLs.

 

[ernieS]

Be careful when sanding. I've heard that the veneer on this series is thinner compared to older JBLs.

That’s a fact. Tread lightly.

 

[bobabode]

Good on you for saving them from scrap heap. Love my L100t3s.