• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Slightly Pushed In Dust Caps JBL 4311

greybeige

greybeige

Active Member
I have a pair of JBL 4311 axw's that I've owned since 1976. Both of the tweeters have a slightly pushed in dust cap (as opposed to fully pushed in). I have heard it said time and again that that doesn't affect sound quality but is there any way to pull those danged depressions back out again without risk of destroying or negatively impacting the function/sound of the tweeter? Thanks.
 
Register to hide this ad
If you have a steady hand you could take the tweeters apart and push the dents out from the back.

/EDIT/ thats if they are dome tweeters.
 
greybeige said:
I have a pair of JBL 4311 axw's that I've owned since 1976. Both of the tweeters have a slightly pushed in dust cap (as opposed to fully pushed in). I have heard it said time and again that that doesn't affect sound quality but is there any way to pull those danged depressions back out again without risk of destroying or negatively impacting the function/sound of the tweeter? Thanks.
Click to expand...

A vacuum cleaner with a hose and a crevice tool. Depending on how much suction you need you can tape off a portion of the opening of the crevice tool.You can have too much suction so be careful. I have also used very small diameter piano wire, take a small piece and bend the end into the appropriate size "L". You can push it in carefully just past the bend, rotate the "L" to the dent and pull out. The hole left in the dust cap is so small you will never see it.
 
On the LE2x series, they have a paper dome and cone. You may be able to get away with simply "kissing" the dome out with some gentle suction (yeah, its not exactly kissing but you get the point). Just be sure to have a dry mouth or your tweeter will get moist.

Usually this works pretty well with just about any 1 inch dome driver or small cone if the dustcap is pushed in. I'd try this a number of times before resorting to poking a hole into it and pulling it out. The hole would need to be sealed to properly load the dome again.

Bart
 
The dome is listed as a separate part, #21606.

An authorized JBL reconer could replace badly damaged ones for about $10 probably.

The full recone kit is $76 list, D8RLE25.
 
mech986 said:
On the LE2x series, they have a paper dome and cone. You may be able to get away with simply "kissing" the dome out with some gentle suction (yeah, its not exactly kissing but you get the point). Just be sure to have a dry mouth or your tweeter will get moist.

Usually this works pretty well with just about any 1 inch dome driver or small cone if the dustcap is pushed in. I'd try this a number of times before resorting to poking a hole into it and pulling it out. The hole would need to be sealed to properly load the dome again.

Bart
Click to expand...

I did the exact same thing with a pushed-in tweeter in my HD880 speaker. Gave is a good kiss and voila!!!, the tweeter is fixed. Of course, it all depends on what kind of kisser you are...:smlove:

But if you really love your speakers, you should do OK :rockon:
 
Hey guys, thanks...I love my tweeters but......

I love my tweeters but there are limits to what I will do!!:yes:

Just kiddin'....I'll go try it now. Pucker up, baby!:D
 
The new 'Suck-O-Matic'

New blues song: "Take me down to the river, mama, my tweeters won't unpooch".
My shop vac won't do it, and it's a hot little sucker. Gave the tweeter a lip-lock. No luck. Got some dust in my mouth, however.
I'm going to devise a special suction tool attachment for my shop vac. Maybe I'll patent it. It'll be kind of a niche tool, so I'll have to sell it for way more than it's value. Just below the cost of tweeter replacement. About $69.99 sounds good. Plus S&H. And you can purchase a 1 yr. insurance policy for maybe $4.95. My net would be about $80.00 per unit.

Don't go away!!! In the last 5 minutes I put together the prototype. I'm willing to share it exclusevely with AKers.

It's a gutted mini-maglite, a shop vac, and some duct tape (I'll develop a more sophisticated seal later). Then there's the "budget" model, which uses a modified plastic tube for a cheap cigar.

Donations for my research will be gladly accepted.

Rick
 

Attachments

  • The 'Suck-O-Matic'.JPG
    The 'Suck-O-Matic'.JPG
    174.4 KB · Views: 172
  • The 'Suck-O-Matic' in action.JPG
    The 'Suck-O-Matic' in action.JPG
    168.7 KB · Views: 182
  • Patent Pending.JPG
    Patent Pending.JPG
    171.1 KB · Views: 137
  • Your tweets will kiss you back.JPG
    Your tweets will kiss you back.JPG
    174.6 KB · Views: 118
  • Now in the R & R department.JPG
    Now in the R & R department.JPG
    186 KB · Views: 136
The 'Suck-O-Matic' demo

I built the 'Budget' model in about 10 minutes. Don't forget my pending patent! Well, just look at the results!

Rick
 

Attachments

  • wrap it with electricians tape.JPG
    wrap it with electricians tape.JPG
    170.7 KB · Views: 171
  • use cap liner as gasket.JPG
    use cap liner as gasket.JPG
    168.9 KB · Views: 151
  • Cut the tube end off and cut cap open.JPG
    Cut the tube end off and cut cap open.JPG
    170.5 KB · Views: 163
  • Before.JPG
    Before.JPG
    172.1 KB · Views: 197
Last edited:
The Rest of the Story

All my pix didn't attach. Here are the remaining from my R & R department:
 

Attachments

  • sealed with tape.JPG
    sealed with tape.JPG
    184.1 KB · Views: 118
The Results

Need I say more? Where's the money?
 

Attachments

  • After (Medium).JPG
    After (Medium).JPG
    75.2 KB · Views: 171
Last edited:
No cigar, dood, but I have the decency not to post a pic of the real deal. :huge:

[Perhaps someone with less appreciation for the creativity of your approach will, tho.... :yes:]
 
Time to Get More Daring...

I had a similar problem although myLE25 wasn't quite so smashed. I fabbed up the "tool" below out of a 1/2" PVC pipe coupling where the "business" end was rounded over so it wouldn't cut into the cone. I taped this onto the end of the shop vac hose.
Suction_Tool.jpg

Problem was that no amount of suction would pull the dome out. I decided that the paper was too stiff and with nothing left to lose, I got out the airbrush and loaded it with distilled water. I then set the airbrush for a soft, almost invisible spray and gently moistened the creased areas of the dome (actually, most of it). I let it sit about 5 minutes and then tried the suction again...and it popped right out. End result is in pic below:
LE25-2.jpg

The pic makes it look a little better than it really is but still a vast improvement.

One point of caution: the moistened dome is prone to ripping so I controlled the suction of the vac with a Variac. Since the vac uses a "universal" motor, I could get away with reduced voltage w/o harm. I'm not sure all vacs will respond to reduced voltage so gracefully as mine did (an ancient Craftsman).

Bottom line: I think you can get your dome popped out and looking good.
 
Thanks, Steve O...I don't have an airbrush anymore. But I think a nice watercolor brush could trace around the dome accurately. I'll try it tonight.

Rick
 
I did the same thing. I took a small artist brush and brushed water on to the dust cap and let it sit for a few minutes, then added another coat of water and let it sit for 5 minutes. After that, I had some clear plastic tubing that I got at the hardware store. It was the same inside diameter as the dust cap after I flared it out by applying heat with a heat gun. I then placed the flared end over the dust cap and sucked on the tube. The dust caps popped right out. Because the tube was clear, I could see when they popped out. I let the speakers dry overnite before using them again.

I did this on both tweeters for my 4311 b's. They look perfect.

I've also done this on mid ranges for my HPM 60's, although there are some crease marks left.
 
You can also fold some masking tape to get a point and then gently pull out dents with that. I suppose duct tape would work even better, but it might leave more residue.

I once fixed a dented dust cap by poking a hole through the dented place with a pin, then bending another pin into a right angle and sticking it through and using it to pull up on the dent. It popped right out and then I sealed the hole with a bit of clear fingernail polish.

Those attachments for the vacuum look good too and I'll have to try that next time I need to fix a dent.
 
If the dustcaps need replacing, I have 'em. 3.2" paper caps, thick composition, no outer lip...

Regards,
Gordon.
 
GordonW said:
If the dustcaps need replacing, I have 'em.
Click to expand...
Do you have the little tweeter domes, Gordon, #21606?

I know how to get 'em off, but not what glue to use for installation of replacements....
 
Unpooching results

I unpooched my dustcaps last week! Came out very satisfactory.

I used a watercolor brush and some water, which I applied about 7 or 8 times to the infected area. then I used my 'special dustcap tool' which is a small shopvac with a hollowed-out cigar tube attached to the end.

After the first application of H2O I waited about 5 min. Didn't work. I applied more water, waited a few mins and still didn't work. 3rd try the caps started to raise a bit. Did it a few more times and finally had results.
 

Attachments

  • After (Medium) (Small).JPG
    After (Medium) (Small).JPG
    54.8 KB · Views: 82
You must log in or register to reply here.
Back
Top Bottom