Dust cap dent remover tool

The problem with vacuums is that if you slip, you risk putting a crease in the cone from the wand. Not worth the risk in my opinion.
 
I do the wet method and tube with great success. The HPM-100's are notorious for their pushed in caps on the mid and high. I use a watercolor brush and water to get the cap moist...wait about two minutes..and then take a 3/4" copper union (anything similar, it was what I had) and positioned it gently over the cap and sucked. It pops right out perfectly. No glues, no vacuum to mess with...nuttin. I would use PVC unions for the different size caps. Of course it will not work on the metal caps but for the cloth ones...perfect.
 
Jlord said:
I meant for the woofer. Shoulda specified that I guess.
Click to expand...
Having played a bit now with DATS I can assure you even woofers are affected. This is most likely the case with heavy caps. Fabric or other caps of soft material aren't as likely, and the shape of the dent has an impact as well.

Not to be dismissed is the gap. The tighter the fit, like JBL LE series woofers, the greater the risk of rubbing or poor performance due to the distortion of the former.

I don't take dented caps lightly anymore. While it may not be readily apparent when listening, using DATS before and after has left me shocked at the difference in performance. Changes frequency response AND impedance curves. Of course the smaller the driver the more prominent the affect.
 
Good info and experience sharing.

Here's a slightly different question: where do you get your dust caps or center caps and why? I use OC Speaker Repair cause they're local but they seem to be expensive, at least for the 3 to 4.5" paper caps I use for JBL woofers.

Any comments and I don't intend to get this kicked to D&S. If borderline, will delete value question.
 
It seems to me that a vacuum would work on all applications other than metal or vented dust caps. Have you ever reduced a full size shopvac down to a half inch hose? You will be surprised at the amount of concentrated suction at that tip. I just wanted to add to this thought because I didnt see anyone mention the use of reducers to make the vacuum more effective, for those pesky ones that you have to use a vacuum on.
 
Luthierman said:
It seems to me that a vacuum would work on all applications other than metal or vented dust caps. Have you ever reduced a full size shopvac down to a half inch hose? You will be surprised at the amount of concentrated suction at that tip. I just wanted to add to this thought because I didnt see anyone mention the use of reducers to make the vacuum more effective, for those pesky ones that you have to use a vacuum on.
Click to expand...

Actually, I did do that and it still did not do the job. I took the circular nozzle from my Auto Armor car vac and affixed to the nozzle of my shop van the hole was reduced to about 3/4 of an inch. The tweeters were still too small for it to be effective and the passive woofers would start to come out but released and snapped back the way they were. The dust cap material on the woofer seems like felt covered plastic.
 
On regular dust caps I use water applied with a large artist brush and then some heat from my heat gun. I wave it over the dust cap area and then reach for my shop vac with a pvc reducer that I have rounded over the end and I go over the dust cap until all dents are out. On plastic dust caps I use a little more heat and the vacuum and keep switching back and forth until the surface is smoothe.
 
hatrack71 said:
I have found a much better way. I snap a toothpick in half and use the wide side of a toothpick. I then take a drop of Aileen's tacky glu and glue it to the indented area. I let it sit for about 4 hours. ...
Click to expand...

Last night I pulled dustcaps of Polk Monitor 7's using glue and earbuds successfully.
I cut the earbuds in half and used Aleene's original tacky glue.
Once glue dried, I pulled them and they are 95% good.
I can see few minor dimples but only from close up.
The glue also came off easily with the earbud itself. :yes:
Thanks for the tip :thmbsp:.
 
FWIW, those tweeter diaphragms are ruined. I mean, they were already ruined, so no harm done, just can't expect the proper response from them in that shape.
 
I dunno - my experience is that even tweeter dustcaps/domes can be fairly mechanically distorted with little audible effect. No, I haven't done polar response plots... :-)

As to dent pulling :-) I am thinkin' that a dental pick would be a fine tool.
 
I don't think polar measurements would even be necessary to show obvious problems, but yeah, I guess it's worth saying that the OP should not feel tin-eared if they seem to sound fine, nor should they feel like I'm full of crap ;). HF problems can sound pretty subtle even when they are technically pretty bad. It just depends. Btw, aren't these KG 2?
 
In the past I've stated over this forum about using hot glue that seems to work great for me.

I lay a piece of string on the center of the dust-cap then drop a "drop" of hot glue over it, and let it cool.

Then carefully (remember I said carefully!) hold the two free ends of the string and pull the string. Sometimes holding the ends of the dome with your other two fingers, helps keep the dome in place. I've also noticed the drop of glue usually comes off and "everybody's happy"

.......And If you don't have a hot glue gun, try using candle wax.

Cheers and good luck to you!
 
goanlisten said:
In the past I've stated over this forum about using hot glue that seems to work great for me.

I lay a piece of string on the center of the dust-cap then drop a "drop" of hot glue over it, and let it cool.

Then carefully (remember I said carefully!) hold the two free ends of the string and pull the string. Sometimes holding the ends of the dome with your other two fingers, helps keep the dome in place. I've also noticed the drop of glue usually comes off and "everybody's happy"

.......And If you don't have a hot glue gun, try using candle wax.

Cheers and good luck to you!
Click to expand...
While this is a pretty cool idea, which I've tried, I've found that some dust caps will peel, which means the glue may come off with a flake of dust cap before the dent comes out. I've tried a couple times with said issues and gave up and went to a dental tool. I would also exercise caution in that the hot glue may be hot enough to damage a plastic cap.

Other than that, some great tips and ideas here. Look forward to trying on some of my more stubborn caps.
 
I was given a pair of Infinity SM152's about 18 months ago and the woofer dust covers are both indented quite badly. Tried tape, no good. Tried the hook tool and got them well shaped but not perfect. The next time I cranked the woofers to 11 the covers indented all by themselves. Not gonna do it again.
My take on them now is this .... I cannot see the covers and they should not effect sound, I will leave them alone.
 
Smitthy said:
The metal dust caps on my Altec 803 bass units are dented is it best to remove them or leave as is.
Click to expand...
If it were me I'd remove and replace them. After my experiments using P.E. DATS it became quite clear that dented caps DO have an adverse affect on performance. Any caps that are reasonably stiff, particularly metal, are also likely to have a distorting affect on the VC, they are only thin tubes after all.

As for Tom's cap(s) being sucked back in, I'm thinking the material is damaged enough that they will no longer sustain the internal "vacuum" caused by the cones excursion. Again, I would personally replace if correct replacements are available.
 
Any more good stories about dust cap dent removal or repair?

Where does one get the dental pick-like tool locally or by mail order? I used to see guys selling stuff like this at computer swap meets.
 
Smitthy said:
The metal dust caps on my Altec 803 bass units are dented is it best to remove them or leave as is.
Click to expand...

If they are aluminum then they aren't 803's.. 803 woofers should have a paper dustcap.If they are indeed 803's then they were reconed using the wrong parts and or dustcap.They sound like 421 dustcaps.

If aluminum and they are dented they should be replaced.I agree with Copa1934 that it will affect their performance.I would also replace with paper dust caps for HiFi.You need to check those woofers to see if they are vented in the rear.If they are 803's they shouldn't be (Rear Vented) and would need to be vented through the cap with a vented dust cap.

803 A-B's are vented through the dustcap..421's are vented through the rear magnet cover.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom