LE10H Voice Coil Rubbing

[Zekeman]

I bought a pair of L96'w almost two years ago that needed refoaming. Just noticed tonight on the one that the LE10 was making noise. Pulled it off and the movement is real stiff and binds unless I move the cone around. I cut off the foam and it seems hte voice coil is rubbing on the side where the terminals are.

Any advice on how to remedy?

Thanks.

[Mannermusic]

Recently replaced the dust cap on a 2213 woofer and found remnants of the foam coil filter had become lodged in the gap. Was able to vacuum out and then cleaned the gap with a piece of naptha soaked thin cardboard. I doubt this is an approved JBL procedure! But, your situation sounds considerably worse and my "guesstimate" is that the suspension is damaged so that the coil is now off center and dragging. How's the coil? Is the resistance normal? If the coil is burned it may well drag as well (warped, wires loose, etc). You may be due for a trip to your local JBL pro. If it was me, I'd cut the cap off and see what's going on in there. Good luck!

[Zekeman]

That is exactly what I did and I have freed it up. Both you and Gordon were dead-on with the foam filter...see AK thread...

http://www.audiokarma.org/forums/showthread.php?p=1673276#post1673276

Thanks.

[Mannermusic]

Nice to win one once in a while - good show. I used a better material to replace that foam - even a fine screen wouldn't hurt, seems to me. :applaud:

[jblwolf]

I'm getting ready to put a pair of LE10A in service,does anyone know if they have the foam filters in them like the LE10H?,mine are late 60's models.

[Zekeman]

Is the filter really required? Gordon says he just leaves it open. My LE10's also have the little screen at the bottom of the hole anyway.

[Mannermusic]

If your enclosure interior is sterile, you don't need a filter. But, seems to me, you have all sorts of fiberglass remnants, small animals (and their excrement), flakes of fiberboard, etc. flying around in there . . . my 4312s were loaded with dirt of all sorts . . . and the cone/coil assembly is pumping air in and out by design (woof, woof!). The louder, the more. So, I assume that's why the JBL engineers put the filter in. Cheap insurance. Bottom line, that passage goes directly into the gap and you gotta keep the gap free of everything . . . AS YOU KNOW. I'll bet JBL ran tests with and without and decided they need it. They just should have used better material (or made speakers that don't last so long!). Gordon has a good point though in that you gotta select a material that isn't going to flake apart just as the original did. We used to have a saying in the lab: "One test is worth 1000 expert opinions." One final observation: I had another 2213 reconed by the local JBL pro, Signature Audio Services (Jeff Keel), and he put a new filter in. I think you need a filter.:blah:

[Zekeman]

OK You convinced me. What type of material did you use for the filter...and where did you get it?

[Mannermusic]

I don't think it has to be anything exotic - even the original JBL stuff seems to last 20 years which will outlast many of us here on the site! But, I used an HVAC Vent Filter material made by True Blue, "Self Charging Material Acts as a Dust Magnet for Airborne Particles." Local hardware. Package of twelve 10 X 30 cm sheets. Intended for use in heating duct outlet registers, cut to size. White in color. Appears to be fiberous and relatively strong - not the soft, polymer foam stuff that seems to degenerate into tar. But, I'll bet any of the fiberous furnace filter materials would be fine - just trying to keep the chunks in the air from getting through but not too fine to be restrictive to air pulsations. Maybe fine screen door screen would be another possibility? Can use the same dust cap glue - I used 3M weatherstrip adhesive 08001 which is similar. We should charge JBL for testing! Mike

[Zekeman]

Great Info...Thanks alot.

I'm in the process of scraping off the old glue from the surround (yes I cut off a perfectly good surround last night in haste) and need to pick up some dust caps and a surround Monday from a local guy. Then we'll have to fix 'er up.

Thanks again!

[Mannermusic]

I'm getting ready to put a pair of LE10A in service,does anyone know if they have the foam filters in them like the LE10H?,mine are late 60's models.

Just looked inside one of my LE10As - it has a screen rather than the foam. You should be good for 100 yrs. or so! Mike

[SMKSoundPro]

I have never, in 20 + years of JBL reconing replaced a foam vented pole piece filter.

I always cut the disintegrating foam away and scrape the residue away with the sharp chisel while getting the basket ready for the new recone kit.

scrape, scrape scrape! sharpen chisel on whetstone, scrape, scrape, scrape.

[edgewound]

The vent filter should always be replaced. It's there for a reason, right?

If it's not replaced, Murphy's Law will kick in.

The vintage speakers used a cloth screen that's coated with some sort of resin that can stretch over time and cause an "oil canning" sound below about 100Hz.

I've found that cutting a circular piece of grill cloth works best as a replacement for the more recent factory "foam plug"...but it needs to be stretched taught over the hole.

[Zekeman]

Thanks all...

Regarding the adhesive...I would recommend 3m Super weatherstrip adhesive #08008 (black in color as opposed to #08001 which is yellow).

Zeke

[Mannermusic]

Thanks all...

Regarding the adhesive...I would recommend 3m Super weatherstrip adhesive #08008 (black in color as opposed to #08001 which is yellow).

Zeke

Roger that Zeke - I had the yellow available for on-going vintage car door seals repair! ;)

[Zekeman]

It is a nice glue though...seems to setup nice and fast. It is expensive too.