Just acqired a pair of L212 speakers ...

[SEAWOLF97]

Some speaker systems are actually designed to play low and don't "need" a sub.

The point that I was trying to make was .... the 250Ti's sound great w/o subs , I had the M&K setup so I could play or not by the single push of a button. Did a lot of comparing with it IN or OUT.

The sub DID add a little more , that I DID NOT know was missing.
Could I live w/o it ? sure , Was it essential ? No.

mine was not designed as a 2.1 and in brutal actuality , in that room the ESS bookshelves (w/ JBL 10in. powered sub) get more use. They have wider dispersion vs the beamey-ness of the JBL's. (and the two systems are orientated 90 degrees differently ie: different listening positions)

[rdgrimes]

I understand what you're saying but not in the absolute . . . try telling that to the 4345 with an 18-inch woofer.

But my statement is still true: There's no such thing as a speaker system that doesn't benefit from a sub. It's got nothing to do with the capability of the speaker.

[hjames]

No - please don't start such a contentious discussion on your Subwoofer beliefs
in the midst of this discussion on restoring a pair of L212 Speakers - its OFF TOPIC Here.

But my statement is still true: There's no such thing as a speaker system that doesn't benefit from a sub. It's got nothing to do with the capability of the speaker.

Fine - but please go argue it IN YOUR OWN THREAD ...
don't thread crap on this L212 thread to make a statement like that ...

[hsosdrum]

Like all foam on 40 year old JBL speakers, there was a layer of foam on the inside of the grills.
As expected, it was crumbling badly, so I removed it, measure it, and packed it away for use as a template later on.

It had a sticky layer that attached it to the grill cloth, but it's no longer sticky.
It was in the upper grill area where the mid and tweeter would reside.
I'd guess when new it was 3/16 to 1/4 thick,
and 10.5 x 14 would just do it - one per speaker, of course.

I presume it enhanced the imaging by separating the sound fileds to some degree,
and I presume it should probably be replaced. Any ideas?

I would try a mat of 1/8"-thick heavy felt, cut to the same shape and applied with thin double-stick tape.

[SEAWOLF97]

I would try a mat of 1/8"-thick heavy felt, cut to the same shape and applied with thin double-stick tape.

I had 2 pairs of L40's . One pair had nothing, but the other had a cut piece of foam on the grilles underside. It looked like carpet padding. I'll try to find the pic .... ah, got it.

I recall it at 3/8 to 1/2 inch

[JuniorJBL]

Those are very cool Heather!!

I like the felt idea too! It might be possible to use the double stick tape to put felt on the cabinet as well/instead for ease of application. (might not fall off as easy either)

Anyways, congrats on another Iconic JBL speaker!

[hjames]

I would try a mat of 1/8"-thick heavy felt, cut to the same shape and applied with thin double-stick tape.

Thank you!
Currently, I am mostly listening to them, but when I do return to tweaking them,
that sounds like a good approach to doing so!

[mech986]

Hi Heather, wonderful job of restoration and driver repairs.

Just for clarification on the below comments, which spider glue joint did you soak - the spider to frame (what I'm thinking) or spider to voice coil (not likely)?

Was the other option to lightly paint the spider corrugations (folds, which many times has a resin coating that gives it stiffness and shape) with MEK and let them resolidify in a new resting position?

Bart

"Get some material that will act as a shim (HJ: I cut some strips longways from 3x5 file cards)
and get the coil centered and level position on the spider.( as seen from the side )

See if there are any "waves" or spider deformations.

If not, then with the speaker face up, soak the spider glue joint with mek (HJ: I wiped it with a wet Q-tip as I spun it on a tabletop) ... every hour or so for a good part of the day...let sit overnight and dry.

Remove shims and see if it's fixed. If it is now happily centered,
reinstall the shims as before and glue the foam."

[hjames]

I used a capful of MEK and, with a Q-tip, I slowly spun the driver and applied MEK to the spider to frame junction.
Apparently, that softened that glue-bond enough that the spider could shift slightly.
I never lifted the spider from the frame, just wet it down.

The other option was to full dissemble the cone/spider assembly from the frame, clean the gap,
and then reglue the spider and surround into place. The risk there is damaging/tearing the spider in the process.

I figured I'd try the first process and hope, and I was lucky.

Hi Heather, wonderful job of restoration and driver repairs.

Just for clarification on the below comments, which spider glue joint did you soak - the spider to frame (what I'm thinking) or spider to voice coil (not likely)?

Was the other option to lightly paint the spider corrugations (folds, which many times has a resin coating that gives it stiffness and shape) with MEK and let them resolidify in a new resting position?

Bart

"Get some material that will act as a shim (HJ: I cut some strips longways from 3x5 file cards)
and get the coil centered and level position on the spider.( as seen from the side )

See if there are any "waves" or spider deformations.

If not, then with the speaker face up, soak the spider glue joint with mek (HJ: I wiped it with a wet Q-tip as I spun it on a tabletop) ... every hour or so for a good part of the day...let sit overnight and dry.

Remove shims and see if it's fixed. If it is now happily centered,
reinstall the shims as before and glue the foam."