4312A "woofer oddity"

[BigBamBoom]

Hello everyone, Although I'm new here I've been an Altec/JBL freak since 1975.
I've a set of 4312A speakers. have had them for about 7 yrs. For their size & what I paid for them they sound great to me. Purchased them in near mint condition. They are still near mint...or so I thought.
On both speakers the woofer appeared canted inward slightly, about 1/8". I held a metal straight-edge ..horizontally across the center of the woofer. With the straight edge carefully placed against the outer frame gasket........sure enough!! No doubt about it, the woofer is "canted inward" on the left of the frame. There is a gap about 1/8" between the cone edge on the left......on the right, the woofer touches the straight edge. Both speakers have this strange oddity.
I only dicovered this about a month ago. The speakers sound great, no problems that I can hear and I've gotta wonder how this can be! Others have told me not ta worry about since the speakers work just fine. I'm just confounded. Perplexed!!
How can a woofer still be working fine....if one edge of the cone is canted inward.....1./8" no-less. Does anyone know if this was a common defect in JBL "white woofers"?
BTW....I never did buy the "woofer sag" myth.....besides, my woofer offset issue is horizontal.
Anyway, just curious that someone out there might know of such speaker oddities. Lansing Heritage is Awesome!!! whoever created this site.......bless you & thanks, RUSS

[boputnam]

Hey, Russ - welcome!!

First, pm thanks to Don McRitchie - he's the Wizard in these parts...

Now, about them 2213H's - I've not "heard" of that condition, nor, being an owner of a fine pair of 4312's L/R, have I noted that. Either you've got a real collector, or there's something anti-gravity going on.

I wonder if someone rotated the 2213H's...? If you could post some pics, we might be able to tell by the position of the voice coil leads on the face of the cone. Also, if that goop ain't drooling off the bottom of the 2213H, but is somewhere else (top...?), then sure enough, those have been rotated 90-degrees.

Looking ahead, what does it all mean? You might consider a recone, to ensure that sag is not mis-aligning the voice-coil. As well, the one Giskard may have observed this, and might chime in here...

And the white, is Aquaplas - a coating added to either the front (in this case) or the rear of many JBL cones. Nearly as legendary as AlNiCo...

[BigBamBoom]

boputnam:
Thanks for the kind welcome. Sorry I've no digital camera to post pics of woofer oddity. .......35mm film still rules!
Anyhow, there is in fact some "goop" at the bottom of one of the woofers in these 4312A's. Indicating (to me) a vertical sit for some time. The "woofer cant" (I don't know what else to call it) is a horizontal phenomenom.....not a vertical one. I'm not gonna lose any sleep over this woofer thing but I find it so very strange is all. You seem to believe in the "woofer sag" theory however. I just don't think it is possible for a woofers cone to....sag. If that were to happen...then everything else (spider/coil/surround, etc, would have to go out of alignment as well.
Although I think Altec/JBL drivers are the BEST ever, somehow mine got past quality control I guess. I just cannot figue out how a woofer can sink inward on one side!! In both speaker systems no less! For whatever it's worth, I bought these things from a local vintage audio dealer who informed me that they originally came from a recording studio. Who knows what they went through before I got them. I played these 4312A's really loud today......still no audible defects that I can tell. Strange.


"at least they're not L100's" boputnam, I take it ya don't like those!!!

What I DO like about "white woofer " JBL.....is the surrounds are designed & built so well. I can't figue for the life of me why JBL put a "rot away" surround on all their big wonderful floorstanders Best wishes, RUSS JBL forever-forever JBL!!!!

[boputnam]

Hahahaha... Much in that post, for sure...

Well, I don't know what I believe in, except JBL , but certainly don't know what to make of the cone cant. Goop at the bottom does suggest gravity, at least, it still working - otherwise (and in general ) I'm clueless.

Maybe some of the rowdier Forumites will sober-up and offer some experiences, here.

Me?? I love L100's (sorry - I get to use that smiley too rarely...)

And, the "rot away" surrounds were quite an advancement in compliance - although they do have a "half-life"... Don't count 'em out!

bo.

[Hofmannhp]

Originally posted by boputnam
.........And, the "rot away" surrounds were quite an advancement in compliance -

Hi Bo, Hi Ross.(welcome to the forum),

is it posible, that the aquaplas coating has a different thickness on the cone surface.....but 1/8" is a lot???
That means that the backside of the cone maybe ok.

HP

[speakerdave]

Those speakers may have been positioned horizontally and not mirror imaged to keep the tweeter/midrange geometry consistent.

Cone sag is real, but as the years go by other things become more important.

David