JBL L100 midrange !!!

[retro soulman]

hello ! i found a pair of JBL l100 century in a very good price (200euro) but the mid-range speakers look a little different, just like the photo http://www.gophoto.it/view.php?i=http://www.jbl43.net/customerfeedback/k-sama-l100-1l.jpg#.Uao3K9jS2Vg

whats your opinion ?? aftermarket or recone ?:dont-know:

[Mr. Widget]

Sun damage/age difference is my guess. The reddish one looks like it has discolored due to environmental issues. I've seen others that looked that way.

Just guessing... either one could be a recone.


Widget

[Robh3606]

They could have been manufactured at different times. Take a look at the label and the color of the tweeter surrounds. The originals were yellow. Latter ones were black.

Rob:)

[Greg86z28]

Is the one on the left an L100a? If you look closely you can see it has the orange JBL logo whereas the one on the right has the black logo

[Mr. Widget]

Is the one on the left an L100a? If you look closely you can see it has the orange JBL logo whereas the one on the right has the black logoYou know, I thought about that but didn't look closely enough. I think you nailed it.


Widget

[Wagner]

For what it's worth, my L100As (close serial #s but not sequential) have always had their grilles in place except when playing music.
I have one mid cone that is considerably darker than the other and it's not from Sun bleach.
And yes, the pair in the photo are two different speakers; one from L.A. the other from Northridge, so definitely mids from two different production runs.

Thomas

[retro soulman]

thats my pair ! can u see the dif between the le5-2??

59302 5930359304

[Wagner]

thats my pair ! can u see the dif between the le5-2??

59302 5930359304

Yes I can.
Looks like a little before and after action with the photos too, one with the tweeter foam diffusers, two not so much!

That degree of difference is about what I have going on as well.

Is that a Grundig or a Telefunken in the background?

Thomas

[retro soulman]

i mean if the midrange cone is original!!

[Mr. Widget]

i mean if the midrange cone is original!!
I think the opinion is they may or may not both be original but even if they are they may not be very closely matched...

I guess the best case is they are original and the same series but one is sun damaged... still not an ideal scenario.


Widget

[4313B]

There were definitely two different LE5 cone colors. Having reconed many of them over the years using genuine JBL recone kits I can confirm that.

[Wagner]

There were definitely two different LE5 cone colors. Having reconed many of them over the years using genuine JBL recone kits I can confirm that.

Thank you for that!
NOTHING beats "hands on", (I have had this conversation/debate 50 times but had nothing to substantiate it/back it up)
In all the years you have handled JBL, was it fairly common to see small "blems" in those LE25 cones?
Common at all in your experience?
Link a wrinkle almost, but the cone/dust cap absolutely having never been door belled?
I have seen it more than a few time and one of mine suffers from it, but I know for a fact that they have never been damaged by injury unless it occurred at JBL?
Just a little deformity and confined to only one spot, NOT a concentric irregularity.
You can feel the imperfection with a finger; it's as if a small piece of trash may have been on the form when they pressed those little cones.
Nipple is untouched.
What say ye?
Thank you,
Thomas

[Wagner]

Like a wrinkle almost, but the cone/dust cap absolutely having never been door belled?
I have seen it more than a few times and one of mine (currently) suffers from it, but I know for a fact (at least with my personal examples) that they have never been damaged by injury unless it occurred at JBL?
Just a little deformity and confined to only one spot, NOT a concentric irregularity.
You can feel the imperfection with a finger; it's as if a small piece of trash may have been on the form when they pressed those little cones.
Nipple is untouched.

Anyone else noticed this (seemingly) production "flaw"?
I only persist in asking as it seems very unlikely (to my mind anyway) to have occurred in such a consistent fashion on the examples I have seen with no other signs of mishandling or damage?
And on every LE25 I have noted this little "flaw" on it was in almost exactly the same spot, to the left of center when viewed from the front.
Am I alone on this?
I am primarily interested on knowing how this may have occurred if anyone has any insight or theories more definitive (factual) than my speculation.
I find it odd that they could "get out the door" from the factory with these little evident "blems". Then again, compared to some of the New England stuff I have handled and seen, they are pristine!
Thank you all,
Thomas

[jbl]

What is the yellowing of the woofer on the left?

[Wagner]

What is the yellowing of the woofer on the left?

The effects of time and environment on the adhesive joint. The glue has changed colors from clear/opaque to the yellowish hue you see in the photo.
This change is common (at least I have seen it on many woofers). Some, more pronounced than others, some, not at all.

Thomas

[hjames]

What is the yellowing of the woofer on the left?

Some time around smokers, perhaps?

[jbl]

Some time around smokers, perhaps?

You may be right. No one smokes at home and my 1975 L100s don't show any discoloration. Thomas, any pealing of the Aquaplas?

[Wagner]

You may be right. No one smokes at home and my 1975 L100s don't show any discoloration. Thomas, any pealing of the Aquaplas?

Every thing is blamed on smokers! (although I agree, tobacco smoke CAN indeed foul things up)
I've seen the yellow glue joints on woofers with pristine white cones, so that's enough empirical evidence for me that something else is going on
May even be the paricular batch of glue
I've have good luck with white Aquaplas woofers and have only experienced small chips on the edges when removing hardened Lansalloy surrounds
I don't think it's anything to worry about
Thomas

[jbl]

Makes sense.

[Wagner]

Speaking of L100 mids; how tightly sealed does the mid chamber need to be? My seal, as far as woofer pressure or turbulence goes (the mid's little chamber or cup) is fine and solid to the baffle and the wires are well sealed at the entry point in the little cup.
These are an original owner pair and the drivers have only been in and out once, but I can feel that those crummy little wood screws wouldn't need much to strip out of the MDF baffle.
I just snugged mine up (a couple not as "snug" as I would like) and counted my Blessings.
Neither of my cabs used a gasket on the mids either.
"OK" or should I try to tighten up those holes or go with some longer screws?
Would they benefit from gaskets? (O-ring seals)

Thomas

[Robh3606]

All the drivers in my L100's had gaskets. "O" rings on the mid and woofer a flat paper gasket on the tweeter. There are groves in the frames for the woofer and mids where the "O" rings fit.

Rob:)

[Wagner]

All the drivers in my L100's had gaskets. "O" rings on the mid and woofer a flat paper gasket on the tweeter. There are groves in the frames for the woofer and mids where the "O" rings fit.

Rob:)


Hello!
Yes, I can see the groove, but no O-ring.
I do have the proper woofer O-rings and the paper gaskets on the LE25s.
Just wondering if any response is lost on the mid with the missing (never installed) O-ring?
They were never there on this pair.
Don't know if the mid's enclosure has to be "sealed" as in acoustic suspension sealed or just sealed well enough to prevent the woofer from interfering?

Thomas

[rdgrimes]

The mids mainly need to be sealed on the inside can. Sealing the outer flange isn't a huge deal, but it really should be well sealed. I'll wager there are o-rings around that will fit the driver.

[Wagner]

The mids mainly need to be sealed on the inside can. Sealing the outer flange isn't a huge deal, but it really should be well sealed. I'll wager there are o-rings around that will fit the driver.

Hello,
Yes, I'm sure there are. Problem is sourcing them. I've long ago given up on trying to source little odds and ends like this from JBL. They don't seem very motivated to fool with this sort of stuff.
I would think they would/should be the hollow type like on the woofers to allow for a nice compression seal without stressing the mounting flange, not to mention the lousy wood screw holes.
I'm going to have to reinforce my screw holes too, during this R&R to double check wiring I became aware of the fact that they're starting to get to that point where they're going to stop getting snug soon and just spin 'round and round.
Don't know why they didn't use T-nuts on these. This big grain density MDF stinks for wood screws

Thomas

[Wagner]

They could have been manufactured at different times. Take a look at the label and the color of the tweeter surrounds. The originals were yellow. Latter ones were black.

Rob:)

I know this thread is ancient; doing some research and came across it.

I thought the original LE25 tweeters had the dark reddish orange surrounds and the later black.

When were they ever yellow? LE20 or LE25s?

Or if you're talking LE5-2s I've never seen a yellow surround on one of those either?

Please advise

Thank you