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daccawash
01-17-2013, 10:10 AM
Inherited pair L100's, tweeters not working, but after testing using 1.5v battery I believe drivers work. Woofers/mids work fine. L Pad pots very stiff but I got them to move. After reading forum posts, I see labor involved removing L Pad from cabinet (taking off foil decal etc) Are L Pads incl. new capacitors available? Seems that buying old unit on EBay might short sighted, since labor is same.

Also, where to find foam grille inserts? Seems FoamTrends and Sculpted Foam Innovators are RIP Help?

Eaulive
01-17-2013, 07:42 PM
Inherited pair L100's, tweeters not working, but after testing using 1.5v battery I believe drivers work. Woofers/mids work fine. L Pad pots very stiff but I got them to move. After reading forum posts, I see labor involved removing L Pad from cabinet (taking off foil decal etc) Are L Pads incl. new capacitors available? Seems that buying old unit on EBay might short sighted, since labor is same.

Also, where to find foam grille inserts? Seems FoamTrends and Sculpted Foam Innovators are RIP Help?

Hello!
There is plenty (and even this is an understatement) of material about the L100 on this forum to keep you reading for centuries (pun intended) Use the search function and good luck ;)

daccawash
01-18-2013, 08:35 AM
Hello!
There is plenty (and even this is an understatement) of material about the L100 on this forum to keep you reading for centuries (pun intended) Use the search function and good luck ;)

Thanks for attempting to help... I admit to learning curve as a newcomer to both speaker repair and this forum. At the same time, I have already spent quite a bit of time searching specific forums, particularly the "foam grille insert" issue. The most recent post on foam grilles seems to be several months old so I was hoping to get some "real time" info.
With regard to the general nature of my tweeter "diagnosis", your point is acknowledged... yes, lots of posts. I've spent hours, perhaps inefficiently, searching.... would like some specific info so I can get going. Thanks for your reply

Mr. Widget
01-18-2013, 09:26 AM
Tweeter advice. Buy a replacement pair. These will have to be used and either from someone here or most likely from someone on eBay.

L-Pad advice, to pull them requires removing the foilcals... very few people have the patience to remove and replace these without noticeable damage to them. I would try cleaners and lubes with them in place.

Foam insert advice... I think Sonofagun is the last guy around who still makes these, but I do know he would prefer to make simplified slab foam replacements. I am not sure if anyone is currently making high quality "Quadrex" inserts.


Widget

macaroonie
01-18-2013, 11:19 AM
Some stuff here http://www.diyaudio.com/forums/multi-way/182612-jbl-l100-restoration-upgrade.html

And here http://www.troelsgravesen.dk/JBL_L100.htm

And here http://www.audiokarma.org/forums/archive/index.php/t-395155.html

And here http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html

Quite a lot of repeat info info but there are other leads that may take you somewhere useful.

I would toss the L pads myself and replace them with fixed resistors.

Just a thought , the foam grilles could probably be done as a one off with a Picture framers Matt Cutter , well at least the grid , the edges would need a little jig and custom blade holder.

Considering how successful and iconic the L100 ( and variants ) was I do find it slightly surprising that there is not a definitive revival plan out there. I suppose you just gotta pick the bits you feel appropriate for your own needs , whether new X/O or port damping or whatever.

There is indeed something special about those drivers , they defined an era.

Good luck with your project. M

daccawash
01-18-2013, 11:40 AM
Thanks for your speedy reply.
The foam inserts are going to vex me but I don't give up easily... Sonofagun hasn't responded to email request...

If the tweeter problem is in the L Pad, I need to try work around instead of removing foilcal, just to access ONE screw. I have a few ideas.

Thanks again for your support.

daccawash
01-18-2013, 11:45 AM
Thanks Macaroonie,
Like I say, I'm a stubborn lad. If I didn't know better, I'd say here's business opportunity!!

Cheers

macaroonie
01-18-2013, 11:48 AM
You heat the foilcal with a heat gun and put a thin blade under the foil as the glue softens. I hasten to add you are not attempting to set these on fire. Touch hot is plenty , they will come away . Don't force the foil or it will wrinkle permanently.

Mr. Widget
01-18-2013, 12:05 PM
You heat the foilcal with a heat gun and put a thin blade under the foil as the glue softens. I hasten to add you are not attempting to set these on fire. Touch hot is plenty , they will come away . Don't force the foil or it will wrinkle permanently.If you look at them cross eyed they wrinkle. ;)


Widget

Mjcaron
01-18-2013, 01:11 PM
I have had good luck with a heat gun and a putty knife removing the foil. Just have to take it slow. I would take out the crossovers to recap them at the least. The backs of the L-pads will pop off with a pair of pliers if you want to hit them with some contact cleaner. (Or replace)

Bought a pair of replacement grill foams from Sculptured foam. They took a while and they cost too much but they are a dead on replacement.

Best of Luck

daccawash
01-18-2013, 01:33 PM
I have had good luck with a heat gun and a putty knife removing the foil. Just have to take it slow. I would take out the crossovers to recap them at the least. The backs of the L-pads will pop off with a pair of pliers if you want to hit them with some contact cleaner. (Or replace)

Bought a pair of replacement grill foams from Sculptured foam. They took a while and they cost too much but they are a dead on replacement.

Best of Luck
Mjcaron,
Thanks so much for your input. Great suggestions all. Time to get to work!!

It appears my biggest problem will be finding those grille inserts. Currently, I cannot find reliable web presence (including EBay) or contact information for Sculptured Foam or Foam Trends. If you have such info I would be most grateful.
Another member Sonofagun has also been suggested as supplier/manufacturer, but I cannot locate him either. So anything you have is helpful.

macaroonie
01-18-2013, 01:50 PM
Do a Google ' cutting foam ' and go to images. From there I found this

http://hackedgadgets.com/2010/10/01/diy-hot-wire-foam-cutter/

By no means a perfect description but the method is there. Cheap , effective and DIY able.

You will need to source the open cell foam and you will need to make templates to guide the wire but that should be reasonably easy if you take some care.

If you are mad keen generate a pdf of the profiles you require and have them water jet machined from glass / SS / Ali. Then you can make lots and lots of grilles.

Way to go.

daccawash
01-18-2013, 02:29 PM
Macaroonie, Mjcaron, et al.
Many thanks for your assistance. As of mid January 2013 here's the current state of affairs regarding replacement foam inserts for the L 100 grilles..... Only one source for these elusive little devils. Just made phone contact with Forum member Sonofagun who, also happens to operate http://FoamSpeakerGrilles.com. Others have referenced him, but apparently the email address I saw posted contained a typo which explains why I got no response. Similar problem on his posted web address.... Sorry it took me so long to figure this one out... hey Moe, Larry, fellas

AmericanPie
01-18-2013, 09:37 PM
Macaroonie, Mjcaron, et al.
Many thanks for your assistance. As of mid January 2013 here's the current state of affairs regarding replacement foam inserts for the L 100 grilles..... Only one source for these elusive little devils. Just made phone contact with Forum member Sonofagun who, also happens to operate http://FoamSpeakerGrilles.com. Others have referenced him, but apparently the email address I saw posted contained a typo which explains why I got no response. Similar problem on his posted web address.... Sorry it took me so long to figure this one out... hey Moe, Larry, fellas


Last year I was ready to place an order for a total of (8) L100 foam inserts (in two different colors) and tried emailing Foam Trends but got no response. From what I've read they have since stopped making the foam grilles and have sold off all their inventory on eBay. Too bad; some folks on this forum had bought from them and had good things to say about their quality/service.

As far as I can tell, Sonofagun is currently the only source for the quadrex foam grilles. A few months ago I bought a set of (4) orange grille inserts from him. It's been at least several decades since I saw a factory-original orange grille so I can't say if they're a perfect color match, but they look pretty good (better than the flat, brown alternatives which are totally devoid of the L100 "character"). I haven't glued them into the wood frames yet but I did try them for size and they seem to be a good fit. They arrived about 4-6 weeks after I placed my order, which is reasonable considering they have to be custom-made. Anyway, no complaints so far.