Dented Dust Covers

[Vintage Nut]

I've got a dented dust cover on one of my 104 mid ranges (120Ti). The speaker still sounds great and I leave the grills on most of the time, but it bugs me. Are there any tricks to getting the dents out of these things?

[Mike Caldwell]

Sticking a piece of tape on it and pulling it back off and hopefully lifting the dent. Gentle use of a vacuum hose. How deep is it dented in. If you try the vacuum trick you need to regulate the amount of vacuum do not just fire up your shop vac and stick the hose on it.

Mike Caldwell

[JBL 4645]

Take a [bog roll] and place it over the dented dust cap and suck backwards on the JBL dust cap, until you hear it pop, then you know its beck in the correct shape, unless it’s a major dent it will not form back correctly, but give it a good suck. Just don’t let the neighbours see you doing it; otherwise they might get the wrong idea.

And please remember to wash your hands afterwards.:D

http://www.veg.nildram.co.uk/troll.jpg

[Vintage Nut]

http://www.ziptrucklines.com/images/100_4198S.jpg

Well, perhaps this answers my question. I don't think even Richard Simmons could fix this one.

I'll keep my eyes open for an undamaged replacement. Are there any other midrange drivers that could be a good replacement to the 104 or would I be better off holding out for 104s?

[Mike Caldwell]

Yea that's punched in alright! The correct diameter vacuum hose that just fits on the dust cap may work. Or a more direct approach take a small pin make a hole in the center and then bend a piece of wire like a paper clip to have a L shaped end on it work it in the hole to lift the dust cap back into place. A small dab of glue to seal the hole. You could call them rare inverted dust cap mid range speakers!


Mike Caldwell

[grumpy]

http://www.harmanaudio.com/search_browse/partlist.asp?BrandId=JBL&MarketId=HOM&Parts=120TITKL

$110 from Harman if they do another run (for consideration vs. Ebay prices)... or a member
here might have one...

As a repair, I'd go with stock if possible ... if for no other reasons, "hot-rodded" systems
tend to deviate from the factory "voiced" sound, and also tend to be worth less.

I'd wait to find the correct part, -if- it was my decision :)

[JBL 4645]

http://www.ziptrucklines.com/images/100_4198S.jpg

Well, perhaps this answers my question. I don't think even Richard Simmons could fix this one.

I'll keep my eyes open for an undamaged replacement. Are there any other midrange drivers that could be a good replacement to the 104 or would I be better off holding out for 104s?


YIKES!

Like I said take a bog roll and place it over the dent and give that good ole JBL a good sucking until you hear the dust cap go POP! ;)

http://www.veg.nildram.co.uk/troll.jpg

[Vintage Nut]

I've already added the 104H to my "wish list" at Harman. I'm a little confused, though, as it also says "not available." Should I call them directly?

I'll try the suction thing, I guess. The speaker is funtioning just fine right now and I'd hate to destroy that, but I guess I've got nothing to loose otherwise. I suspect it will never be a perfect dome again no matter what I do.

Anyone got a spare 104H they would part with? I'll post a WTB in the for sale section of the forum.

Thanks for the help!

[grumpy]

I'm a little confused, though, as it also says "not available." Should I call them directly?good question. I believe this means they might do another production run. I don't know
if that having them on a "wish list" does anything more then let them tally a level of
interest; or if anyone at Harman would somehow notify you if production resumed
(I would certainly like to hear so! :)) -grumpy

BTW, that foil dome will -not- ever look the same, but the audible effect of such damage
(if limited to the dustcap) on the sound, is (as you've found) unlikely to be a major upset
while waiting for a replacement. (I'm not guaranteeing inaudibility, nor that differences
are immeasurable, ... just that this happens with annoying regularity and no one has
died from it yet... that I'm aware of).

[JBL 4645]

I've already added the 104H to my "wish list" at Harman. I'm a little confused, though, as it also says "not available." Should I call them directly?

I'll try the suction thing, I guess. The speaker is funtioning just fine right now and I'd hate to destroy that, but I guess I've got nothing to loose otherwise. I suspect it will never be a perfect dome again no matter what I do.

Anyone got a spare 104H they would part with? I'll post a WTB in the for sale section of the forum.

Thanks for the help!

No harm in calling them directly.

[opimax]

would it be possible to replace just the dust cap? and you might make a thread about getting enough people together to make it worth JBL's time to do a another run...I have heard it has happened before on some tweeter kits for example

Mark

[Phil Ivkovich]

Try hot glue with a wood stick. After pulling glue can be peeled off. Worked for me.

[mbottz]

All these solutions are great, but if it is made out of aluminum it will never look nice and smooth. The easiest way to fix it is just contact Rick Cobb and purchase a new one. The old one will peel off pretty easy from the poly cone using a razor knife or blade, then just glue the new one on in the same place. I have done this with all my metal dome mids.

Now if it was a paper dome that is a different story. One thing to add to the suction ideas is to dampen the paper dome just enough to get it wet but not enough to penetrate into the voice coil. Do this prior to suction. This will make the dent pull out much easier and when it drys it will look almost like new. Make sure and moisten the full dust cap or else you will leave a water ring after it is dry.


Mb

[Vintage Nut]

Thanks for all the replies, folks. I've tried the suction thing without success. Save a small hole in one of the grills, my 120Tis are pretty much perfect. So, I'm thinking I'll just track down another good 104H or have mine reconed professionally. That may not be the cheapest route, but will have the best results.

Now, if I could only find another good 104H . . .