JBL L112 ?'s

[cloneofkane]

Good evening,
I believe I have a bad 044 tweeter (need to verify still with multimeter) in one of my JBL L112's and I'm trying to remove. (I've already posted a WTB for a 044 on BT Parts)

I removed the screws and the speaker fell towards the inside of the speaker. I disconnected the leads but it's too large to remove from the tweeter hole in the cab (see attached picture).

1) Do I need to pull the woofer out so I can remove the tweeter? I am guessing so -- as soon as the tweeter fell toward the inside, I began to wonder how I would re-secure unless I had a hand pushing from the inside out so I could screw in. Figure I need to reach up through the woofer hole to hold the tweeter in place while I secure with the screws.

I removed the 4 woofer screws and the the woofer will not budge. I read somewhere that there might be a sealant of some kind holding it in place and that I should use a knife to run between the outer flanges of the woofer and the cabinet. Does this sound right?

2) While I have the cabinet open, I figured I would de-oxit the l-pad controller. I read that I should feel for a vent but I really cannot feel one. Does someone have a picture of where the vent would be so I can figure out where it is inside the cabinet?

Appreciate the advice! I am nervous as heck about messing around with this because they are in pretty much pristine condition otherwise. I don't want to screw it up aesthetically but am hoping this is something I can handle on my own.

Thanks,
Dave

 

[turnitdown]

The vent should be below the tweeter on those. Take the woofer out. Remove the tweeter and whatever is left of it on the baffle. Try to re-mate them taking particular care to get the coil into the gap without damage. (All advice is relevant if I have the correct speakers and nature of your problem)

 

[cloneofkane]

The vent should be below the tweeter on those. Take the woofer out. Remove the tweeter and whatever is left of it on the baffle. Try to re-mate them taking particular care to get the coil into the gap without damage. (All advice is relevant if I have the correct speakers and nature of your problem)

I removed the 4 woofer screws, but it won't budge. Is there a sealant of some kind holding it in place? Any suggestions for how to remove without doing damage to the cab face round the woofer hole?

Once I get the tweeter out, I am not sure what you mean about trying to re-mate and get the coil into the gap. Greatly appreciate more detail here, please.

 

[opossumcrush]

I layed mine face down on a couple of 1 x 2s and let gravity do the work for me.

 

[cloneofkane]

Okay -- got the woofer out and was able to pull the tweeter out.

Sorry for my ignorant questions, but do I remove the tweeter from the baffle using a hex key? And then reassemble?

 

[absolve2525]

Hmmm, your tweeters look to have Titanium diaphragms? Stock is normally an aluminum painted phenolic. Nothing wrong with Titanium, just wondering if they were swapped out with a Ti version?

 

[absolve2525]

044 diaphragm shown here. The tweeters show up fairly often on Ebay.

 

[cloneofkane]

044 diaphragm shown here. The tweeters show up fairly often on Ebay.

Do I just need to replace the diaphragm, not the entire 044 housing?

Attached is pic of the housing, if that helps.

 

[absolve2525]

Have you tested the resistance of that tweeter with a meter? Before disassembly, I would check it. It's always a gamble trying to open these tweeters. The diaphragm can be destroyed in the process, which is why I would make very sure its bad before opening. Yes, you use a hex wrench on the four screws and the metal plate comes off. You just have to get lucky on Ebay or barter town etc and find a working pair, which is more common than finding good diaphragms. They are no longer made.

 

[cloneofkane]

Good stuff -- thank you very much! I will test it tomorrow before doing anything else. If it is indeed a goner, it is recommended then to just buy an entire tweeter than attempt to replace the diaphragm?

One more question: while I have the speakers out, I thought it would be a good idea to de-oxit the l-pad controller pots (see attached). Do I try to fit the plastic straw into on of the holes on the end of each pot? Or is is there somewhere else I should find to spray into?

 

[absolve2525]

Yes, I had to buy whole replacement tweeters for my L112. My crossover parts and l-pads were also fried, so I had to get new crossover resistors, caps, and l-pads. If you can reach your staw inside, shoot lots of cleaner into holes on the back of the l-pads. If the straw is too short, others here have made straw extenders. Try to rotate the speakers around so that the controls are flushed and turn the knobs continuously to get cleaner distributed. If that doesn't work, you can pull the l-pads but the foilcal decal has to be removed. The nuts are accessed underneath. That's the last resort, however. I've heard others used a heat gun to loosen the glue under the foilcals.

 

[cloneofkane]

Tough to tell from this pic, but there is a "vent" near the base/bottom of the pot that I was able to get the De-Oxit tube in. Gave both a good bath and turned the knobs a bunch -- I didn't notice any static prior in the mid (which works) prior to disassembly, but hopefully once I get a new 044 installed, the l-pad will be in good shape and ready to go.

 

[absolve2525]

Yup, hopefully you can spray enough into the various vents and get the cleaner all around. They make a syringe version of Deoxit, which would be handy for shooting it into small openings.

 

[turnitdown]

Looks like you're doing quite well.

 

[cloneofkane]

Looks like you're doing quite well.

Thank you -- while I hate looking at two holes in my cabinet, it feels good to be figuring this out -- and I'm very thankful for the guidance along the way!

I haven't been able to borrow a meter yet, but am anticipating the 044 is toast. I'm hoping script56 or someone else on AK has one or two stashed away for me!

 

[cloneofkane]

Finally tested the 044 and zero reading, so now I know.

Besides BT Parts, the auction site and CL, any other suggestions for where I should look for 1 or 2 044's?

 

[cloneofkane]

I bought a JBL Recone kit D8R044 that surfaced on the auction site for $38 shipped. Is it as simple as replacing the old part (marked 12104) with the part included in the kit?

It looks like there was glue or an adhesive holding the diaphram down onto the surface -- any glue work or a recommended glue to use?

 

[cloneofkane]

Here are pictures of the recone kit D8R044

 

[Zonker92]

Yes; just substitute the new part for the old one.

I don't think fresh adhesive is necessary; the old tape may still be sticky and the screws and clamping force should keep everything snug and stable. But you might want to replace the damping foam under the dome. A Google search should reveal some threads on that.

 

[cloneofkane]

Yes; just substitute the new part for the old one.

I don't think fresh adhesive is necessary; the old tape may still be sticky and the screws and clamping force should keep everything snug and stable. But you might want to replace the damping foam under the dome. A Google search should reveal some threads on that.

Thank you for this and I will check the foam when I get home. Any characteristic I should look for in the foam that's there or just best to always replace when performing this work?

Also, I hope this isn't too ignorant of a question but better to just ask so I know: if I checked the new diaphragm on its own when I receive with a multimeter, should it read 5.7, or does it have to be assembled and married up with the driver and magnet to register a reading?