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tensleep
03-17-2008, 04:46 PM
Hello and thanks for the wonderful forum. I have learned a great deal already and plan to learn more and contribute when I can, hopefully from success with my various projects. Making mistakes can teach valuable lessons, but usually at the expense of my pocket book!

I purchased a pair of 4410 speakers new years ago (1986?). Now, they are in dire need of some help. I have not had them out in probably 7 years, so imagine my surprise when I found the surrounds disintegrated.

Reading about how common this is put most of my fears to rest! The dust cap is also pushed in on one of the L127H (my 3 year old pushed a toy through a hole in the grill years ago). The grills need to be repaired (broken posts, have all the pieces, need new fabric) and the veneer needs to be oiled as well.

The surround repair is very well documented elsewhere on the forum. Can someone please point me in the right direction for the following:

Source for replacement grill cloth - original would be nice, but a close match will have to do.
How do I make the fabric release from the grill frame?
Dust cap removal/replacement - similar to surround repair?
The magnets for the 35ti pair both have a small, round foam pad (?) on the center pole (?). They have deteriorated like the surrounds. Replacement suggestions?The driver windings all measure well for impedance, the spiders look great, I don't believe that the mids need anything. I'm not sure if I will dig into the crossovers just yet.

I intend to archive the whole process with pictures and text. Some of it may be redundant, so lemme know, moderators, if you want less.

Here are pictures of the drivers out of the cabinets, before any repairs.

http://www.micksmothers.net/gallery2/v/Billy/

JSF13
03-17-2008, 04:59 PM
JUst a FYI. I had to repair a post on one of my 4410 grilles recently and had good success with Krazy Glue Advanced Formula. You have to be careful not to put too much glue on and press the pieces together considerably longer than the 30 seconds they suggest (until the glue dries) but if you do you will get a nice solid repair.I've removed the grille several times since the repair and no problem.

tensleep
03-25-2008, 06:09 PM
I picked these up over the weekend (add in the local paper). I believe that they should do until I complete the 4410s!

http://www.micksmothers.net/gallery2/d/24980-1/System+with+Barzilay+Cabinet.jpg

More picture of the Bozaks:
http://www.micksmothers.net/gallery2/v/Billy/Bozak+Speakers/

I'm currently listening to Chet Atkins, Mr Sandman - beautiful! Now I need some Les Paul next.

hmolwitz
03-25-2008, 07:35 PM
Rudy Bozak (http://en.wikipedia.org/wiki/Rudy_Bozak) had a long and interesting career in audio, and is worth looking into. most of his speakers were worthy, though very different than the "West Coast Sound" of Altec and JBL.

tensleep
03-25-2008, 08:33 PM
I certainly enjoyed reading about Mr. Bozak's contributions to audio. His story and place in history resonates with that of Nikola Tesla.

I figure the money is well spent, too; I doubt that I'll find any JBLs better than my 4410s, or in such great condition, for a C note.

Gotta get my surrounds for the L127H next. I have a response from Mr. Cobb and intend to order them tomorrow. I have a great workspace setup and some fresh blades for my exacto - guess I'll have to lay off the coffee the day of the surgery.

I'm still looking for suggestions on chemicals/processes for bringing the shine back to the titanium domes. Or should I just leave them well enough alone?

badman
03-28-2008, 11:17 AM
I'm still looking for suggestions on chemicals/processes for bringing the shine back to the titanium domes. Or should I just leave them well enough alone?

Leave Well enough Alone on the titaniums.

tensleep
04-04-2008, 05:47 AM
Well, I started in on repairs last night. I removed the damaged dustcap, gasket and old surround remnants from the basket. It got late, so I didn't have time to remove the old surround remnants from the back of the cone.

I tried to post pictures, but they were huge; is there a quick way to resize an image in html?

Anyway, here is a link to my progress:

http://www.micksmothers.net/gallery2/v/Billy/JBL+Speakers/Repairs+0408/

A couple of questions:

After I removed the dustcap and could see down into the throat (?), I noticed a fiberboard tube that lined the walls of the throat and descended into the voice coil gap of the magnet. I have read about shims for reconing, so I got to wondering if this tube is part of the speaker construction or a shim (I'm original owner, never had these reconed)? The tube is cut perfectly, so I assume that it is part of the structure.
Some of the dustcap adhesive flaked off in a couple of spots during removal of the dustcap. It doesn't look like it will be a problem, but I want your opinions.
The gaskets/surrounds certainly were well attached to the basket! I have trimmed and scraped quite a lot of material away. Where can I get and what is MEK (some type of sovent, I assume).Thanks for all of your advice and experience - I'm having a blast! Especially, thank you Bo for your excellent and comprehensive tutorial in the sticky!:applaud: I certainly went through a much more thorough preparation before diving into this because of it.

richluvsound
04-04-2008, 06:27 AM
Hi,

heat will release the old adhesive on the grill cloth . Send a Pm to Zilch ,he may have a source for the original cloth

Rich

Earl K
04-04-2008, 06:28 AM
Hi,

- I looked at your pictures .

Your Questions ; ( please excuse my paraphrasing )



1. Cardboard Tube ; shim or something else ?
2. Removal of Dustcap Adhesive flaked off a couple pieces of the cone . A problem ?
3. MEK ,,, what & where ?

Answers ;

1. You're looking at the "former" that provides the "shape" & location , to wind the voicecoil onto . ( ie ; it's not a reconing "shim" ) . These formers are also sometimes made of aluminum or plastic .

2. I couldn't see this in the pics ( I could only access the thumnails ) , so it's hard to comment on .

3. MEK is shorthand for; Methyl Ethyl Ketone ( ? ) . It's highly aromatic / so only use it in well ventilated spaces .
- It's a bit hard to find / ie; it's not a standard retail item found at Home Depot or Lowes .
- Consider trying acetone first, instead of MEK . ( it's much easier to find & is fairly effective in "goo" removal )

:)

grumpy
04-04-2008, 07:08 AM
http://www.jtbaker.com/msds/englishhtml/m4628.htm

It's useful, but serious stuff. Make sure you know what your dealing with.
It can hurt you.

Baron030
04-04-2008, 11:53 AM
Quoted by tensleep:
I tried to post pictures, but they were huge; is there a quick way to resize an image in html?

I am not sure that you can resize an image in html?

But, I would suggest that you use something like Microsoft Photo Editor to resize your images.
And here are a few photo tips that I use whenever I post pictures on this site.

1. Start by opening your raw image file with Microsoft Photo Editor and then immediately saving the file under another name. This prevents you from overwriting your original image file.

2. Next, crop off all unnecessary extra space around your subject. And don’t be concerned about trying to keep any standard photo height to width ratios. If the subject’s composition is square then crop the photo until it is square.

3. After cropping then resize the photo until it is no wider then 800 pixels in width and no higher then 1024 pixels in height. And the reason for using a maximum width of 800 pixels is that your photo will be displayed completely on this web page without any scroll bars on most computers.

4. Next, adjust the brightness, contrast, gamma, and color balance to bring out any fine details.

5. Don’t forget to save your editing results often; otherwise you will be saying “D’Oh” a lot. Personally, I save everything as “.JPG” files.

6. If you are including several photos within your LH posting, then try to adjust the width, brightness, contrast, gamma, and color balance so that they all appear uniform to each other. It will give your posting a very polished look.

Baron030 :)

brutal
04-04-2008, 11:58 AM
... snip...
The gaskets/surrounds certainly were well attached to the basket! I have trimmed and scraped quite a lot of material away. Where can I get and what is MEK (some type of sovent, I assume)....snip...

I've never had trouble finding MEK at any Home Depot, Lowes, or most hardware stores. Acetone IMHO evaporates much too quickly for removing surround glues.

I picked up a few tiny hobby squeeze bottles with very narrow tips to use for saturating q-tips for surround removal from the cones, and to better control the application on the basket edge. MEK vapors attack the cap cover, but doesn't seem to bother the plastic bottle or top.

Careful with this stuff, it will discolor your cones if dripped or you apply too much on the backside when removing the old materials. If the surround is very dry/powdery, I just scrape off as much as possible with an assortment of Xacto knife blades, and then rub with a MEK soaked Q-tip to blend in the old glue and remove lingering surround material. I just did a pair of 122a-1 and found for the first time the Aquaplas coating on the backside had been partially applied over the surround edge. After doing most of the cleanup, I re-wetted this edge and used an Xacto chisel blade to carefully remove the thin sliver of Aquaplas stuck to the surround. made for a clean and solid repair when I re-glued the new surround.

After scraping the basket edge with a chisel Xacto, I saturate it with MEK, being careful to avoid the cone face, let it set up for a few seconds and then start scraping/peeling the old surround/glue off. If it's original, leaving some of the glue residue behind on either the cone or basket is OK, as long as it's fairly smooth and even, and gives the new glue something extra to bond with IMHO.

grumpy
04-04-2008, 01:10 PM
if you use solvents much, these might be helpful:

http://www.hmcelectronics.com/cgi-bin/scripts/product/5520-0007/

just make sure you affix a lable so you don't forget what's in it...
& have a metal cab to store it in (with your other "blow-sh*T-up" chemicals).

Earl K
04-04-2008, 01:51 PM
I've never had trouble finding MEK at any Home Depot, Lowes, or most hardware stores. Acetone IMHO evaporates much too quickly for removing surround glues.

Oooops, sorry for the misdirection . My bad .

- This may be a Canadian Controlled Substance issue, ( or Maybe just ADD on my part ) .
- Now, I'll need to research this question .


:)

brutal
04-05-2008, 11:06 AM
Oooops, sorry for the misdirection . My bad .

- This may be a Canadian Controlled Substance issue, ( or Maybe just ADD on my part ) .
- Now, I'll need to research this question .


:)

No worries man, I didn't see that you live in the land of Nanook of the North. :D

I'll trade you some MEK for cheap prescription drugs... :thmbsup:

I know the ADD thing. I tell everyone I have AOADD (Adult Onset ADD). Goes well with the CSS, CRS, CFS diseases I have. Can't See/Remember/Find Sh*t) :blink:

tensleep
04-07-2008, 04:49 AM
I know the ADD thing. I tell everyone I have AOADD (Adult Onset ADD). Goes well with the CSS, CRS, CFS diseases I have. Can't See/Remember/Find Sh*t) :blink:
250Ti.L112(2).4312BMkII.4310.S38.18Ti.L166.L86.L56 .L55.L80T.L20T.L100A

So is this why you have such a collection of cool speakers - you can't remember where you left 'em?:coolness:

Thanks for all of the suggestions everyone, especially the safety concerns! I usually avoid tetramethyle death, but sometimes ya gotta have the right chemical for the job.

I usually post my original pictures to my family website, hosted by my brother, in full resolution for the details. I also have them native to my hard drive, so I suppose I can create duplicates at a smaller size. I'll give that a shot.

I intend to get back to my 4410 restoration this week. I'm currently working on a privacy fence, decking the attic, and assembling my road bicycle as well, so I'm stretched. But, they're all labors of love!

A couple of other questions:

I separated (carefully) the titanium diaphragm/voice coil assemblies from their magnets (035ti) and found that the foam pad (?) between the dome and the pole piece (?) had deteriorated as badly as the surrounds. I assume MEK will remove that material, but where can I get/fabricate replacements? Rick Cobb doesn't stock them.
I have read about using folded painter's masking tape to clean the voice coil gap - why don't we use bottled air, like we use for cleaning keyboards? Condensation?Thanks again for the help!

Earl K
04-07-2008, 05:44 AM
Hi

Foam ?
Here's an older thread I dug up somewhat about repairing a 035ti . (http://audioheritage.csdco.com/vbulletin/showthread.php?t=10161&highlight=damping+Pads)

- The pertinent info is that the foam should be replaced so as to provide much needed mechanical damping to the titianium diaphragm .

- Edgewound may know if these pads are available / if it was me, I'd be trying out the different types of foam that I have sitting around here ( roadcase foam of all sorts ) .

Gap Cleaning ?

- With small metallic particles, you'd be surprised at just how tenacious the magnetic hold is . Compressed air will usually just move this type of particle to another location in the gap.
- Inside-out masking tape, wrapped around a stiff business card is a much more effective way at cleaning these sort of particles out of the gap .

<> :)

tensleep
04-08-2008, 05:09 AM
I have some pictures to document my progress. They are very similar to Bo's post, with a few differences. I had to remove a dustcap, as well as the gasket from the basket.

Please comment on the old dustcap adhesive. A few pieces/chunks flaked off during dustcap removal. I removed all that was loose and made sure that the rest was secure to the cone. However, I can't help but be concerned that over time, more of the material will flake off and get into the voice coil gap.

Workspace

http://farm3.static.flickr.com/2420/2398509936_22bcea5649.jpg?v=0

Clean, open surface
Comfortable chair
Good lighting with magnifying lens
Exacto knives with a blade assortment
Small vacuum cleaner
Turntable (lazy susan from Wal Mart)

Closeup of Damage

http://farm3.static.flickr.com/2363/2398510050_302c5867e1.jpg?v=0

Dustcap Removal

http://farm4.static.flickr.com/3050/2398510076_e010508a46.jpg?v=0
http://farm4.static.flickr.com/3080/2398510234_7d316f4bd8.jpg?v=0
http://farm3.static.flickr.com/2331/2397678495_e6d078da4d.jpg?v=0
http://farm4.static.flickr.com/3272/2398510338_ea4ed0506e.jpg?v=0
http://farm3.static.flickr.com/2232/2397678597_0ba205ae40.jpg?v=0
http://farm4.static.flickr.com/3079/2398509994_e71caba621.jpg?v=0

tensleep
04-08-2008, 05:23 AM
I'm not used to the LIFO format for this forum; these pictures were supposed to preceed the dustcap removal.:crying:

Here are pictures of the gasket removal (is gasket the right term?). The adhesive is tenacious, to say the least! I could not locate MEK at my Home Depot, but will continue to look. In the meantime, I have a product called Goof Off that is more user friendly (read less effective) that may do the job. I also keep mineral spirits around to use as a solvent on bicycle parts. Has anyone tried that as an adhesive solvent?

The basket rim is scraped fairly clean, but I have done nothing to the back of the cone yet.

http://farm3.static.flickr.com/2282/2398510010_cf8a533302.jpg?v=0
http://farm4.static.flickr.com/3051/2397678471_d9a00ea129.jpg?v=0
http://farm4.static.flickr.com/3279/2398510140_aac1bece65.jpg?v=0

The blue tape came in very handy. Periodically, I would use a piece to remove the material that I had scraped loose. I also covered the voice coil to prevent contamination. Some adhesive is still present, and the back of the cones need to be cleaned. It was late and my bed was calling, so more later!

tensleep
05-08-2008, 06:32 PM
This is a very slow going project, but I am making some progress between building a privacy fence and working on the wife's '95 850 Turbo. Thanks again to Bo for the great resurround process with pictorial; I am just adding my experience to his method.

One thing I found that helped was to support the cone with a plate, being careful not to bottom out the voice coil. Also, I couldn't find MEK in small quantities, so I tried Goo Gone which worked well to loosen the surround material from the cone and the gasket material from the gasket. I did have to be carefull removing the last bit of surround adhesive from the cone. Some of the cone material (nothing substantial) was removed (scraped away) with the adhesive before I got the hang of it.

http://www.micksmothers.net/gallery2/d/26074-1/surround+supported+by+plate+_1_.jpg
http://www.micksmothers.net/gallery2/d/26081-1/surround+supported+by+plate.jpg
http://www.micksmothers.net/gallery2/d/26077-1/surround+supported+by+plate+_2_.jpg http://www.micksmothers.net/gallery2/d/26079-1/surround+supported+by+plate+_3_.jpg

tensleep
01-25-2009, 03:56 PM
I am in the process of relocating to Texas, so I have not been able to work on these speakers until to day (lame excuse). I am staying with my cousin who happens to have a large shop, so I am taking advantage to do some work on the cabinets.

The cabinets are still in great shape, but need to be refinished, so I have sanded them and am coating them with boiled linseed oil/turpentine. Here are the befores:

tensleep
02-08-2009, 06:27 PM
I had forgotten just how good these monitors are! I reassembled them yesterday and have been auditioning many of my old favorites. Because of where I am staying, speaker placement is less than optimal. However, these are such a good speaker system that they sound great even out of postion.