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glen
10-01-2007, 11:35 PM
I really wanted to see those great foam inserts on my speakers even though I'm not ready to permanently install them yet.

A long time ago I had some Cerwin Vega speakers with foam grills that attached to the cabs using velcro and thought I would try that to install these inserts.

Since the foam is very coarse I looked at the hardware store for the velcro kit with the biggest hooks I could find.

Velcro Extreme, specifically designed for rough surfaces, had the biggest hooks. The kit contained five 1 inch by 4 inch strip pairs (hooks and loops) with adhesive revealed by peeling off the non-stick backing.

I figured I would use two strips, cut into eight one-inch squares, for attaching each insert.

glen
10-01-2007, 11:59 PM
The intructions said to allow the adhesive to cure for a few minutes before attaching anything to the velcro. The biggest hooks are still pretty small, but very strong and evenly spaced, so I planned to use some plastic spring clamps with square jaws to hold them in place while the adhesive cured.

Where the old glue/foam on the grille frame was lumpy and uneven I tried to scrape it down a bit using a small Xacto knife (mainly in the corners and the two middle spots).

If the old glue/foam was laying pretty flat and even I didn't bother scraping it away.

I would peel the backing off a one inch square, apply it to the frame, and clamp it down, leaving the clamp on for about ten or fifteen minutes.

My clamps wouldn't reach the two velcro squares in the middle, so I slipped a pocket book under the fabric behind each one to support them and stacked some old encyclopedias on top to apply pressure while the adhesive cured (no picture, just looked like a pile of books)

glen
10-02-2007, 12:16 AM
With all eight squares of velcro hooks stuck on each grill frame I layed the foam insert in the frame.

Then I applied a little pressure on the front of foam to attach it to the velcro, this felt a little touchy because the foam would collapse a bit.

They look pretty good now, not sure if it's enough velcro to keep them in place for a long period of time, or if there would be any point in using velcro once I get some JBL badges and there would be no reason to remove the inserts.

Of course velcro might make installation of the third set of Quadrex inserts easier in the far-flung future when George Jetson picks these up at my estate sale.

indycraft
10-02-2007, 10:37 AM
Thanks Glen for the how to with Velcro.

I wasn't aware of velcro extreme in the small packs. Velcro also makes a nearly identical product call MVA 8. It comes in 25yd rolls. The extreme packs look like the perfect installation product.

Bart

glen
10-02-2007, 03:08 PM
The extreme packs look like the perfect installation product.
Bart
I'm actually not confident about these holding up for repeated attach-detach cycles.

As I recall the original velcro hooks were little fibers that stood straight up until their tips curled over when heat was applied. I believe these type of hooks retained a little springiness so when the loop material was pulled away the hooks would uncurl a bit so the loops were relatively undamaged.

The hooks on this stuff look really sturdy and stiff, when used with the supplied loop material they hold quite strong and it feels like loops are being torn up when pulling them apart.

The foam goes on and removes much more easily, but if it is suffering a little damage each time the insert is removed and installed then the attachment may get weaker with use. If I can find some of the old curly style hooks that are as large as these I might try swapping them out.
(I did try smaller velcro as used on cable ties etc. which did not hold well at all)

It's still a better choice for me right now, and I don't think that any breaks in the lateral foam links that the hooks would snag would significantly impair the foam insert's permanent attachment with glue at some later date.

I'm thinking that I want to give the velcro a pretty good trial to see how well it holds up and whether I have enough attachment points to avoid sagging.

Mostly I'm really happy to see my speakers with those marvelous quadrex foam fronts!

Now I juast need a apir of badges . . .

Titanium Dome
10-02-2007, 04:32 PM
Now I juast need a apir of badges . . .

Yep. There's a cottage industry for someone (and perhaps a trademark infringement, too). It's interesting that the original badges were attached with Velcro®. It's still on the back of mine. (Which I'm not selling BTW.)

indycraft
10-02-2007, 05:35 PM
I thought there was someone who made plastic reproductions of the badges.

LRBacon
10-03-2007, 07:46 AM
I thought there was someone who made plastic reproductions of the badges.

There is, Bart. I bought a pair from a fellow on ePay.
They are pretty close to the originals. What I did notice is that the relief of the letters is not quite as deep as the originals and since they are plastic they weigh less. My grilles are completely aftermarket. Your quadrex inserts, rww1951's frames and ePay plastic badges. They look fantastic.

Larry

glen
10-03-2007, 09:48 AM
It's interesting that the original badges were attached with Velcro®. It's still on the back of mine.
I was wondering if they made special badges with a longer back stud to extend all the way through the thick foam. The badges on the cloth grills have stud on the back that's about 3/8 inch long, too short to extend through the foam insert.

Were your badges simply backed with the "hook" type of velcro to attach directly to the foam, or was there a piece of the fuzzy "loop" material applied to the foam as well? Did the badge still have a stud?

Please post a picture of your velcro backed badges if you can, I was unaware of this detail about the quadrex grill construction.

Maybe I'll just leave mine sans-badge for a while.

We don't need no stinkin' badges! :biting:

Titanium Dome
10-03-2007, 10:00 AM
I'm in the process of moving, so they're packed away. :(

To answer your question, though, there are Velcro® hooks attached to the back of the metal badge. They simply inserted into the original Quadrex Grille and grabbed the strands of the foam.

Mine were installed and removed several times as I moved a lot in the 70s and had young kids to boot. After too many insertions and removals, they were less firmly attached. The removal of course was completely unnecessary, but my kids had bad habits where the L100s were concerned.

They got more than one patty slap for pulling out the badges or crushing the grille foam. I love 'em, but the little buggers could not resist those grilles, and they ruined them faster than any normal deterioration would have.

:bash:

rww1951
10-03-2007, 12:50 PM
Glen, my badges are original and were applied with Velcro® very similar to what you purchased. They used the hook side, cut the same size as the logo badge. I can take pictures if you want to see them, but it’s pretty simple.

glen
10-03-2007, 11:48 PM
Glen, my badges are original and were applied with Velcro® very similar to what you purchased. They used the hook side, cut the same size as the logo badge. I can take pictures if you want to see them, but it’s pretty simple.
If you can get a close up picture I would appreciate it.

I'm very curious how similar the stuff I bought was to the original, especially since Dome says they stood up to quite a few attach/detach cycles.

sonofagun
10-09-2007, 06:10 AM
As my grille ordering info says:

Velcro Hook Fastening Tape
One piece, 1" wide, black, made specifically for holding foam in place is available at $2.00 per foot. Tape is cut with scissors into small pieces around 1-2" long or 1/2" wide strips and has self adhesive backing for applying to speaker front. Foam sticks directly to the tape hooks and may be removed or replaced as often as desired. Approximately 6" of tape per square foot of grille size is recommended for each grille. Please be sure to specify with your order whether or not you want velcro tape. Alternately, grilles can be permanently fastened in place using contact adhesives.

rww1951
10-12-2007, 04:57 AM
Glen, sorry for the delayed response. Here's the metal badge with the Velcro applied.

glen
10-12-2007, 10:15 AM
Here's the metal badge with the Velcro applied.
Thanks a lot, it does look very similar to the material the I found: molded hooks in even rows. But your real JBL velcro seems to have more space between the hooks, which may make it easier for the hooks to get deeper into the foam. The "stalks" of the velcro hooks on the badge also look a little bit thinner, so they may be more flexible and less damaging to the foam when separated.

I would expect the original JBL velcro to hold slightly better and maybe have a longer life in attach/detach cycles than the Extreme velcro that I used. Guess I'll keep my eyes open for a velcro that more closely resembles the original.

Thanks very much for the picture!

glen
06-16-2008, 09:58 AM
Well, after several months I'd have to say that the velcro has not proven terribly successful in my case. I think because the foam is not attached in enough places it has a tendancy to slump and sag a little over time (maybe the onset of summer has something to do with it as well).

I guess glue is the answer.

LRBacon
06-16-2008, 10:24 AM
Glen, at the suggestion of rww1951 I used silicone rubber to glue the quadrex inserts to the frame.

Larry

indycraft
06-16-2008, 11:58 AM
Hello Glen,

Roger has come up with installation instructions for gluing. I will email them to you.

Best Regards,
Bart


Well, after several months I'd have to say that the velcro has not proven terribly successful in my case. I think because the foam is not attached in enough places it has a tendancy to slump and sag a little over time (maybe the onset of summer has something to do with it as well).

I guess glue is the answer.