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boputnam
07-13-2003, 08:21 PM
What follows is an attempt at a step-by-step photo and caption Thread for resurrounding a JBL low-frequency transducer. I thought I'd compile this since I was doing a pair, and it might be of interest.

Every resurround I have done is just a bit different – got it’s own unique issues. The 2122H’s done here were quite simply the easiest I have worked on – the surrounds were happy to come off.

So, what follows are learned techniques that work fine, are gentle on the cone, spider and coil, and achieve good results. Most of all, I am deeply indebted to my new-found friends, Rick Cobb (mailto:rcobb@tampabay.rr.com) (looneytune2001 on eBay), who mentored me through my first, seemingly terrifying experience, and whose instructions gave me the confidence to give this a try. His kits fit perfect, and instructions are excellent - use these pics as adjunct to his kits. And, "thatguy" here on the Forum who made the introduction, and likewise was enthusiastic about "doing it yourself".

My engineer had a great idea he shared over iced Corona’s while in New Mexico last week – in the 1970's, he placed the transducers on a “Lazy Susan” to do this work - a hilariously smart idea, because you keep rotating the dang thing for the entire project! Good thinking. Also, I try and cover the rear of the magnet/motor with masking tape to avoid scratches and soiling it with old surround.

Be patient, keep good music rolling through your version of the littlest Altec's, and be persistent.
------------------------------------------------------------------------------------

First, my idea of a workbench. Stand-up, covered with a rubber “Borco” mat that protects both the table and the transducer. Those cabinets on the wall are littlest 1974 vintage Altec Coronas refitted with LE8T and LE20, and a Cross-Tech 2-way crossover. Sweet…

Tools are close-up glasses, Swiss army knife and #10 Exacto. Lights are a mix of movable spots and floods, and two chic warming lamps to keep the basket warmer than typical coast-side foggy…

boputnam
07-13-2003, 08:21 PM
The 2122H has the thin hard-rubber ring on top of the surround, into the edge of the basket, and must be removed. Insert tip of knife straight down along basket edge, into the break in the ring, and gently pry away, and remove.

boputnam
07-13-2003, 08:22 PM
Another view

boputnam
07-13-2003, 08:23 PM
You can see the surround, which “looked” fine, is actually quite decrepit and crumbling. I usually first cut the surround off the basket, and then gently cut it off the cone – knife blade angled in slightly toward the cone to remove some of the old surround off the cone at the same time. DO NOT BE TEMPTED TO PULL THE SURROUND as the risk is too high you might tear the fragile edge of the cone.

boputnam
07-13-2003, 08:24 PM
Merely trim all around, and carefully remove the bits of old surround – they can be gummy, and even tar like when in the worst state, and will get insoluble black goop on any-and-everything.

boputnam
07-13-2003, 08:25 PM
After cleaning all you easily can, place the #10 blade flat in the basket edge, and work around like a putty knife scraping all the glued surround off the basket – both the flat and the vertical edge. Be careful - for better cleaning the knife edge often faces toward the cone edge and might damage it if you slip, but keep you free hand clear, too!

boputnam
07-13-2003, 08:25 PM
These surrounds were so ready to come off, that I was able to carefully draw the #10 blade toward me, angled into the cone and working around the cone-edge, simply lightly scrap the surround off. A breeze and most atypical!

boputnam
07-13-2003, 08:27 PM
More commonly, you will need to invert the transducer and gently scrap the surround off the cone edge, working steadily around (and around and around…) the woofer. This is tedious, and it’s had to get good light on the subject. To avoid undue and uneven tension on the spider and reduce off-axis position of the coil, I place a ½” slab of birch under the cone – it fits inside the edge of the basket - to give support.

boputnam
07-13-2003, 08:28 PM
A typical “Rick Cobb” kit, ready to go, with the 30Hz test CD, too.

boputnam
07-13-2003, 08:28 PM
Ease the surround into position, working around the cone.

boputnam
07-13-2003, 08:29 PM
For this basket, I resorted to this method of applying the glue – not my favorite nor most common, but the fit was SO good, there was no room for alternatives. I gently pushed open the cone edge, and worked around the surround with a bead of glue (exaggerated here for the picture – keep this type of activity to a minimum). More typically, you should put thin beads on both the surround and the cone edge, let dry a spell, then tack together. But, that approach wasn’t possible this time.

For this 2122H, I let it set a spell, and then begin pushing the cone-edge and surround together, repeatedly until it sticks. Wipe away excess glue quickly – it is water soluble while soft.

Note that at this point, the surround is NOT yet glued to the basket...

boputnam
07-13-2003, 08:31 PM
View of the surround and cone edge, with the wet glue. Looking good. The glue dries clear, so it looks even better when dried. Periodically, keep working around the cone edge, one finger behind, one if front, gently pushing the surround and edge together.

boputnam
07-13-2003, 08:31 PM
While you wait for the glue to dry, you can start cleaning the hard rubber ring. You need to scrap off the old glue. This is one of the more time-consuming tasks, and can be sped up with a Dremel, but use one sparingly.

boputnam
07-13-2003, 08:32 PM
NOTE: I mistakenly omitted the picture for this step!!

After the surrounds have healed to the cone edge, glue the surround to the basket. As in the prior glue step, gently bend-up the surround while laying a glue bead along the basket edge, working around the basket. After the glue "tacks up", gently press the surround onto the basket, and work around and around the basket getting a good seat.

Note that from here on out, the transducer is connected to an audio source – you should be playing the 30Hz test tone through the transducer to ensure the voice coil is centered. I use a CD Walkman on "repeat" mode... LISTEN TO THE TEST TONE FOR ANY MECHANICAL SCRAPING OR RUBBING SOUND.

The picture shown here is AFTER the surround has dried to the basket edge, and you are ready to glue the hard rubber ring into position. Lay a thin glue bead all around the edge of the surround, as close as possible to the corner of the basket.

boputnam
07-13-2003, 08:32 PM
Now, its time to put the hard rubber ring into the basket edge. Run a thin bead of glue around the basket (see previous picture) – let dry a bit.

Ease in the hard rubber ring – note the butt-end join in the upper right. Before you slip this in, but a dab of glue on each butt-end. Gently press the ring into place, wiping off excess glue.

boputnam
07-13-2003, 08:33 PM
The two completed baskets, hooked-up and running the 30Hz test tone for the entire drying cycle. This is what the drying phase looks like. It's a bit boring, but oh-so-important. Keep that 30Hz tone playing constantly - it ensures the voice-coil is centered, and allows you to hear if things need adjusting. Check on them periodically, but go find something else to do
:band:
and let them dry...

boputnam
07-27-2003, 06:07 PM
In resurrounding a pair of 2245H's today, it occurred that I had omitted a handy way of appyling the glue bead to the cone, in tight-fitting instances. These instances are when you cannot have the surround in-place while laying the glue bead.

When you simply cannot get glue to the cone edge any other way, a means is to hold the frame on-edge, while slowly rolling the cone, trace a thin bead around behind the cone, with the tip of the glue container as close to the edge as possible. Good lighting is necessary, and avoid excess glue which could drip (but that is not fatal...).

Once the bead is applied and a minute-or-so has passed, slip the surround into position, working around into behind the cone edge. With the glue bead at/near the cone-edge, the glue is smeared nicely across the surround mounting surface, giving it a good grab.

Done.

DavidF
07-27-2003, 06:24 PM
Thanks for the effort to include all the photos, Bo. Interesting to "watch". I have not reconed or even renewed surrounds but a thought I had prior to trying this is to put the driver on a turntable that may assist in getting around the driver. Using the test tone to align the driver during the process would work against this idea. Have you ever tried using a turntable and would this help in any steps of the process?

Thanks, David F

boputnam
07-27-2003, 06:44 PM
Hey, DavidF...

No sweat - I queried Giskard prior to posting all this and he agreed this might be a worthwhile effort. It's not hard, just unusual work. I wish I'd had a photo-path before my first - resurround, that is! :D

The turntable is a good idea, but you want to rotate it manually, and back and forth. I included a comment about a LazySusan in, I think, the first post of this Thread. The FOH pro engineer in New Mexico who looks after my (nearly 3-decade :eek: ) band, used to tour with a number of bands in the 70's/80's, and they did this work on the road, on the fly. They used a LazySusan, which is a great idea. And, it would really only come-in handy during the cleaning round-and-round.

During the 30Hz drying/positioning phase, you will want things VERY unmoving (and quiet!!). And, be real patient, and relaxed here - let the glue get tacky before you really try and get the surround and frame to stick. And, only press down gently, and straight down. If you try anything quick or "efficient" you will invariably move the surround very slightly, and might get things off-axis.

Guido
07-31-2003, 03:42 AM
Thank you very much for this Bo!
I was looking for such a detailed description a long time.

If you ever do a reconing, would you do pictures and description as well?

This would be great :) :) :)

boputnam
07-31-2003, 06:48 AM
"If you ever do a reconing, would you do pictures and description as well?" Ugh! I considered doing that while reconing a 116H last weekend, but felt I was deluding myself in thinking anyone cared on all this ;)

There isn't a great deal more to it - the cleaning is the biggest hassle. That damn Bostex crap is inconsistent to remove, depending upon age and what it's glued to. Only additional steps to a resurround are:

Carefully cut the spider off the basket - use sharp Xacto knife (#10 blade my choice). Remember, the voice coil is in the gap, so don't act impetuously...

Cut the surround away, as per this Thread. But a bit more carefully since the spider is not there to stabilize the voice coil in the gap.

Lift out cone/spider. Use this to create or add to the interesting shrine you have of completely useless parts that are somehow too invaluable to simply discard... :rotfl:

Immediately cover gap and pole-piece completely with masking tape. Begin the dreaded cleaning. Take your time. Clean away all dust and debris completely. Then, take a thin piece of cardboard and run it around inside the gap making sure there is nothing there. A trick learnt from an old reconer (thanks, Giskard! ;) ) is, if you can, reverse a piece of masking tape on this to gather anything from the gap.

I prefer the recone kits that are pre-assembled cone and spider - they're easier to get everything aligned, and less to do! :eek: Carefully slip the assembly into position - check for fit, and alignment of mounting holes through surround (if relevant).

With the assembly in position, thread the voice coil leads throught the terminal connectors. Leave the leads as long as needed - not too long, not too short. A slight "sag" in the leads seems about right. Solder. Trim excess. It is critical to get these leads soldered before proceeding, to allow you to run the 30Hz test tone through the transducer for centering while gluing.

Carefully, lift-out the cone assembly as much as possible. Keep it vertical. In some instances, you may be able to carefully lay it over the edge of the basket - the length of the soldered leads, and the terminal position on the frame, are your limitations. The benefits to carefully doing this, is you can get the gooey Bostex on more evenly where you want it, and not all over everything else. But be VERY mindful the voice coil is exposed and vulnerable. Just be careful, dang it!

Spread a good coat of Bostex on the basket - it's typically old, and poorly behaved, so get it on good and even. Slip the cone assembly vertically and very carefully back into position, and gently press the spider down into position into the Bostex. Start the 30Hz test tone. Listen for any "rubbing", "scraping", of "fuzzing" sound, and see if very slight budges to the spider relieve this. NOTHING DRASTIC, just gentle budges into position - but you need to sort-of push/pull from opposite sides of the spider at the same time. You should hear nothing mechanical from the cone - only the soft free-air resonance of the 30Hz tone.

Keep the warming lights on, and the 30Hz test tone going the entire time until dry. Do not leave the building, or come back to this Forum to see what is going on out here. Stay with it, and it will last another 20-years...

I need to do another 116H, but await a much-needed kit. If there's any pictures worth posting, I'll do so.

Good luck!

Don C
07-31-2003, 08:33 AM
I am surprised that you don't mention shimming the voice coil to keep it straight. Didn't JBL originaly line things up by putting a shim tube inside the voice coil, and then removing that when the glue has dried? I would thing that it would be possible to duplicate that by finding some flat materiel that fits the gap and rolling it into a tube.

boputnam
07-31-2003, 09:08 AM
"I am surprised that you don't mention shimming the voice coil to keep it straight." A "shim" tube is included in the recone kit - it is thin, clear plastic, and helps maintain and protect the coil form. I don't think I could "roll one" that precise! ;)

I removed the tube as I slipped the voice coil into the gap. The fit was too snug to cram it in with the voice coil. I did try and did not want to force it into the gap: I actually had some difficulty getting it back out. I can only speak to this case, and the tube could not be fit into the gap without risking damage to the coil. Other kits/fits may vary, but with this one (C8R116A) that's how it went.

The 30Hz tone ensured me things were aligned - only the most minor adjustment was needed. The results were excellent. Sweeps afterward are noiseless, and the performance seems perfect. :)

Thanks for the tip! ;)

LE15-Thumper
08-23-2004, 09:10 PM
What exactly do you mean by "minor adjustments" during the 30 hz test tone period ? Are you talking about actually shifting the cone over in a certain direction so it doesn't rub ? If so, how do you do this while the glue is hardening ?

TIA

GordonW
08-23-2004, 09:25 PM
Wow, I always use a shim when reconing. I've been burned too many times, reconing drivers, to EVER not use one. Unlike a refoam, there's TWO dimensions to get right- 1) side-to-side offset of the voice coil and 2) "cocking" or angling the voice coil in the gap, where it may hit near the ends of travel even though it's "clear" in the middle of the range. Not something I care to try to eyeball, especially when gluing a spider to a basket!

In my work, if a provided shim doesn't work, I get or make another one. One thing that makes a great "emergency" shim- take those shiny, hard-paper junk mail advertising sheets that come in the mail (pizza ads, etc), and cut them into long strips. Then, take the strips, and wrap them into cylindrical layers to form a multi-layer shim "tube", until you get enough layers to fill up the gap to where the voice coil fits snugly (but not so snugly you can't get the shim back out easily) in the gap. Works great!! Also, the clear plastic from report covers works great the same way- and is preferable, if available, since it won't tear if you get it in there too tight, not as easily as paper. But, the shiny paper works fine, if you use common sense...

Oh, another tip: if you make sure that one side of your shim stock has a PERFECTLY STRAIGHT edge, and you bottom the shim out against the pole piece (shove it ALL the way in as far as it can go, until the shim bottoms out), it will keep the shim PERFECTLY SQUARE in angle with respect to the pole piece. Great way to avoid problems with case (2) misalignment, as mentioned in the first paragraph...

Regards,
Gordon.

boputnam
08-24-2004, 06:59 AM
Originally posted by GordonW
Wow, I always use a shim when reconing. Yup. Gordon's right as always.

TIA - I've had some that just wouldn't align, no matter what. And, you can try this if you get recones off eBay that rub. Working on sound advice, using MEK I've softened the glue on the surround and then the spider, carefully loosening one, then the other. Then clean the basket and reglue and then man-handle ( ;) ever so gently...) first the spider, and then the surround/cone into alignment as the glue is drying.

creinys
12-16-2004, 12:10 PM
Bo, that was a real good and clear lesson on resurround. The pics are great.
I may tackle it on the 125A, was not a LE-15. I was wrong. What model is the mid, high on a decade 36? Could not find in library. Thanks Bo, Chet

Ken Pachkowsky
12-16-2004, 12:47 PM
Nice job. I do believe I recognized those 2122H's.:)

Ken

transducergeek
12-20-2004, 05:27 PM
Bo, that was a real good and clear lesson on resurround. The pics are great.
I may tackle it on the 125A, was not a LE-15. I was wrong. What model is the mid, high on a decade 36? Could not find in library. Thanks Bo, Chet

Hi Chet. If you mean an L36 3 way system? I had one and it used a LE5-5? midrange 5 incher for the High/mid unit. and a LE25-2? 1.4 inch tweet. And the 127A? 10" woofer.. This is from memory, I could be wrong..I sold the units about 3 months ago after re-surrounding the woofs and fully cleaning the rest, Poorly stored when I obtained it from someone who just did'nt care, it was filthy with actual mud on the veneer/grille, not kidding..... A nice "rescue" job. Now in the home of a music lover and hooked up to an old Fischer tube job and the new owner loves it! Makes one's heart feel good..


Thanks to all the Forum, guy's..
Rolf E.

boputnam
12-20-2004, 06:19 PM
Yea, transducergeek - thanks for the help.

I missed this whole exchange :rolleyes: , but smartly, Chet started his own L36 Decade Thread, and the guys that know the line came-in with part numbers and the rest.

hector.murray
01-16-2005, 08:00 PM
Just completed a K120 recone based on this thread. Great info!

Rusnzha
12-25-2005, 02:26 PM
Did my first re-surround on a set of L46s. These little buggars sound great. Thanks for the info, It costs more to recone them than to replace them. What a waste! Now they're good for 15 more years. i don't think I would have done it if not for this thread,:applaud:

westend
10-11-2006, 09:28 AM
I know this is an old thread but I thought I'd give it a bump for those new to LH looking for excellent instructions on refoaming/reconing woofers. Also, an "attaboy" for Bo for the good pics and instructions. I am watching the glue dry on a pair of L111a's , out of 4313's. At least I have that 30 hz tone to keep me company:) .
I found a little trick doing these. An 8" wire tie is just the right width to press down the foam into the frame when gluing. Grasping the wire tie about an inch from the end and lightly pressing the foam down, while turning my lazy susan , made for a very efficient placement. No glue on the fingers, as well.

JPTL
01-17-2008, 06:15 PM
First and foremost, huge thanks to Scott Koeller (SMKSoundPro) for helping me through my first attempt at this.
Scott – thanks for your immediate replies to my PMs, your clear answers to my questions and your expert advice.
Secondly, big thanks to Rick Cobb, who supplied a ‘Beta’ surround, free of charge - then the complete kit (Foam Surround JBL 125A/127H, 116A/H (http://cgi.ebay.com/BEST-Speaker-Foam-Surround-Repair-JBL-125A-127H-116A-H_W0QQitemZ350015936098QQihZ022QQcategoryZ3276QQss PageNameZWDVWQQrdZ1QQcmdZViewItem)) for the refoaming job. He then followed up with post-purchase support and immediate replies to a few questions that I had. Since the surrounds for the 125A are a tad smaller than the L56 woofer dimensions, I was hesitant at first. Scott’s post and Rick’s ‘Beta’ surround, as well as GordonW’s post (http://www.audioheritage.org/vbulletin/showthread.php?t=9238&highlight=l56) gave me the confidence to do this job to the degree of success that I achieved.
The result:
I now have two vintage woofers that sound and appear to be brand new. If I didn’t know that these were refoamed, I wouldn’t be able to tell, sound-wise and appearance-wise. The job went perfectly.
In a nutshell, with some gentle stretching and patience, the 125A kit works beautifully for the L56 woofers (and any other speakers that use the L56 woofers).
I took pictures of all steps from start to finish, if anybody is interested.

readswift
01-17-2008, 06:40 PM
thx for letting us know about your source & success, ordering stuff righht now :)

oh and a question, what to do with expired glue from genuine JBL cone kit? I have one 2007, and another 2008 feb..

SMKSoundPro
01-17-2008, 11:56 PM
Golly, I'm floored! (speechless)



I am so glad everything worked out for you! Please know, that with a little patience, anything can be achieved!


Please post the pictures, if you choose. I am sure someone else will benefit from them. The moderators will make sure they are in the right catagory.

Question to the Moderators:

Is there a catagory of recone, refoam, rediaphram, resetting polepieces... anywhere here on LH where forumites can learn from others. A basic how-to for these wonderful tranducers and their supporting parts?


Regarding tubes of glue. I throw them in a box with all of my reconing stuff, and will use what ever tube is not dried out. No reason to chuck it if it is not all dried out. I use it on other electronic repairs.

I even convinced Lisa to ALWAYS carry a small roll of solder in her handbag at all times.You never know when you might need it!

Bottom line, I am very humbled to be thanked so beautifully for something that is so basic in my life.;)

Scotty.

ratitifb
01-18-2008, 02:12 AM
Question to the Moderators:

Is there a catagory of recone, refoam, rediaphram, resetting polepieces... anywhere here on LH where forumites can learn from others. A basic how-to for these wonderful tranducers and their supporting parts?:applaud:

please share your knowlegde and know how with us. THANKS :p

JPTL
01-18-2008, 07:36 PM
So, here’s how it went:
After getting this pair of L56’s I realized that the original surrounds were brittle and one had developed a hairline crack in it (which quickly spread 1/2way around the roll).
http://members.rennlist.com/jptl/JBL%20004.jpg
Apparently the surrounds in these woofers is different from many in that it’s more of a non-porous rubber material than a foam. Since the material had hardened from age considerably, I’m guessing that even if the surround weren’t yet cracked, woofer performance would have been hampered due to lack of flexibility of the surround. Anyway, the second was obviously on the way out as well.
http://members.rennlist.com/jptl/Surround%20repair%20001.jpg
In doing a search here in the forum for suitable surrounds; and seeing that Rick was recommended as a good source for resto. surrounds in this forum, I looked at his auctions in eBay. Rick didn’t have any specific surrounds for the L56.
Scott and Gordon had mentioned their success in refoaming L56 woofers using the surrounds for 125A woofers, and I asked Rick about that. Being as that he had never done an L56 refoam, he was hesitant to sell me 125A surrounds with an endorsement that they’d work in my case. What he offered was to send me a test surround – free of charge - to try the fit before buying his 125A kit. I took him up on his generous offer, and tried the test surround.
Using Scott’s post as a reference, I warmed it and gently stretched it by putting the material between my thumb and fist.
http://members.rennlist.com/jptl/Surround%20repair%20012.jpg
I worked around the entire surround, and test fit it to see if it was getting close to the right diameter. It still wasn’t quite big enough, so another stretch around the diameter, and the second time was a charm.
One thing that I noticed about these foam surrounds is that they have a memory and a moderate stretch will return back to the original diameter in a day or so. That’s a good thing. So the stretch should be done just prior to the install/glue.
After buying the complete kit and following Rick’s directions (which are very well written, clear and very easy to follow), I removed as much of the old surround as I could, using a sharp utility knife, a good, clear work area, plenty of light and patience. It’s best to start by freeing the cone from the old surround. This way, the remainder of the surround can be cut away without disturbing the cone and risking damaging the coil.
http://members.rennlist.com/jptl/Surround%20repair%20008.jpg
A couple things to mention: the trim ring/gasket on these woofers is in 4 pieces. It’s the first thing you’ll remove and the last to re-install. If you’re concerned about aesthetics of your speakers, take your time in removing these. They’re soft and easy to damage, so use a new, sharp utility knife so as not to shred them up too much, because you’ll need to reuse them. Secondly, the portion of the original surround that’s adhered to the underside of the cone was glued in so well, and was still strong and very evenly adhered, that trying to remove it would have been a mistake. Figuring that the adhesive has held up for 20+ years, I can’t see it failing anytime soon. The remainder of the surround was smooth, very even and very secure. With a quick consult w/Rick, I decided to leave it and glue directly to it.
http://members.rennlist.com/jptl/Surround%20repair%20006.jpg
The adhesive that Rick provides w/his kit works well and 10+/- Q-Tips help to get it spread evenly throughout the job. This adhesive looks much like Elmer’s glue, and has a very workable setup time. It’s easy to work with. Plus it dries clear so any visible glue isn’t too apparent when it dries.
Rick includes a 30 second test-tone CD that puts a low frequency through the woofer to helps to align/seat the voicecoil and test for misalignment. Following the instructions, the cone bounced silently, indicating that it was properly aligned. This is a nice test for peace of mind – allowing for adjustment prior to the adhesive setting up if needed.
All in all, this was a huge success in my mind, figuring that this was my first attempt at anything like this.
Finished product:
http://members.rennlist.com/jptl/Surround%20repair%20015.jpg <<<(the glue hadn't fully cured in this pic.) http://members.rennlist.com/jptl/Surround%20repair%20016.jpg http://members.rennlist.com/jptl/Surround%20repair%20017.jpg http://members.rennlist.com/jptl/Surround%20repair%20019.jpg

brutal
01-18-2008, 08:25 PM
I was able to remove the old Lansalloy by soaking it with a Q-TIP wetted with MEK. I used a fresh x-acto blade to angle cut through the old surround down to the cone, then gently started to work under it and peel off the surround.

That sucker was stuck on pretty good, even with the MEK soaking (not so much it ran into the cone) but I was able to peel the entire surround off in pretty much one piece. Any time it started to resist, I just applied a little more MEK and used A LOT of patience. The old glue was probably well broken down as the Aquaplas underneath was yellowed and likely gave up the fight due to that sparkly coating the older Aquaplas'd drivers seem to have.

I had one or two tiny spots of the Aquaplas lift off with the surround, but after the full cleanup, sealed the offending areas with Rick's glue. There's one spot still showing that I'll touch up with a paint pen or whatever I can figure out. The cones aren't as yellow as the shots would indicate. I like to avoid the flash and let the DSLR do it's thing, but I had the white balance stepped down a bit from taking some black gear shots.

The trim ring was another story altogether. What a bugger! The old yellow, rubbery glue was a biotch to get off using liberal amounts of MEK, scraping, rubbing and ragging. The glue was much easier to get off the frame using MEK and my flat x-acto chisel blade.

First up, the test fit using the retainer ring and Rick's 30Hz test CD. Nearly a perfect center, but the surrounds seem maybe 1/16 too small on the outer dia. at rest.

I applied the glue to the cone first in a continuous bead, then spread it using a small artists brush with my finger propped against the frame and turning the driver to get a nice even curve.

While it tacked up, I attacked the new surround using the same method. I notice the glue sets up a little quicker on the surround so doing only 1/4 or 1/3 at a time - lay a bead, spread, repeat seemed to work best to get edge-edge even and smooth coverage.

I laid the surround into position and carefully started to apply even pressure around the edge, ensuring the surround edge and concentric rings on the cone are nicely aligned, increasing pressure and area, always supporting the back of the cone with my finger(s) as I worked my way around several times. I did not have a turntable, but always protect the backs with blue painters tape, and this moves rather well on a smooth work surface. Once satisfied it was perfectly centered and stuck, I moved onto the next one and repeated the process.

After leaving them to setup for several hours, I laid down a bead of glue on the frame and spread it out a little. I prefer this to a single bead or I tend to apply too much and get spotty drips. Performed the 30Hz centering procedure and then installing the ring to hold it in place (important not to use so much glue it will seep out and stick the ring.) After another 15 mins or so to let it stick up well, I carefully pulled the ring and applied a bead of glue where the horiz and vert of the frame meet each other and pressed the ring back into place, cleaning up any excess that oozed out with my brush and a wet rag. Again, a rinse and repeat on the other and they're done!

Sorry I didn't take any WIP pics... Here's the finished product before remounting in the cabs. LH limits the pic attachment size but the hi-res is avail if anyone would like them via e-mail, just PM me. These low-res, low quality pics don't do them justice.

They sound significantly better. They do "play to the knees" to quote Zilch, but I'm fairly impressed with the bass response of these hooked up to an old Yamaha CR-1020 receiver. The LE20 certainly need help... But that's another project. :D

And as we all know, this driver had the Lansalloy attached to the front of the cone, and the cosmetic preference should be to do the same with the refoam.

Cheers!

Don C
01-18-2008, 08:28 PM
Nice work.

Zilch
01-18-2008, 10:31 PM
Beautiful!

I can almost hear 'em.... :thmbsup:

johnaec
01-19-2008, 06:32 AM
'Great job!

John

Robh3606
01-19-2008, 07:20 AM
Nice job!!

Rob:applaud:

boputnam
01-21-2008, 08:23 PM
...Is there a catagory of ... refoam ... anywhere here on LH where forumites can learn from others. A basic how-to for these wonderful tranducers and their supporting parts?Uh, yeah. It is a "sticky" thread right at the very top of the DIY sub-forum - numero-uno, so to speak.

I'll merge this joyful sharing with that thread...