QUESTION: JBL Speaker Rattle

When the rubbing is very slight you can usually cure it by unbolting the speaker, rotating it 180 degrees and bolting it back in. Everything sags slightly the other way and bits that were touching stop doing so.

Eyesight alone is not a judge of condition. If you poke at them, they should not tear.

That may work. If the voice coil is good, a suround repair could also center the driver, but it may be a little more difficult to make it look orginal when done due to the center piece.

greg

One easy thing to try is to mount the speaker the other way up. Otherwise get it re-coned. This may or may not be cost-effective.

More than likely, the speaker was overdriven and the voice coil hit the pole piece and warped the coil. Recone or replacement is the only solution then.

There is a chance that the spider has come unglued. CHeck under the cone in the basket area to confirm the spider is firmly connected to the cone and the speaker basket. I have not seen this in a JBL, but i have seen it before (not very often though)

Speakers of the 10/15 year old vintage often suffer from dry rot of the cone surround. Check closely for any MICRO fracture of where the surround connects to the basket or the cone itself. THis is the first stage of self destruction.

bob

According to my reader, the last time this crossposting clown posted in ukra was 18/05/07 to ask for free advice with questions about more dodgy old gear, splashed across a different spread of newsgroups and then failed to acknowledge the bunch of helpful replies he received....

Hmmm....

Then you don't know how to read your reader, asshole.

If you ACTUALLY did the research you claim to have done, you will find that I have consistently and publicly thanked the people who took the time to help me.

...And I will thank YOU to keep your smart-ass comments to yourself in the future.

This is the last you'll hear from me. If you want to satisfy your juvenile urge to flame me some more, go right ahead. I won't take the bait.

Have a nice day.

The words 'piss off spammer' spring immediately to mind...

A strange spammer who isn't trying to sell or promote anything...

--

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW To e-mail, change noise into sound.

Hi Keith - long time no speak. How's it hanging ? Missus OK ? FWIW, this guy posts often on s.e.r. and I have never known him to be impolite or to fail to acknowledge any responders to his questions, myself included.

Arfa

I had that effect in some Pioneer speakers way back when because the foam surround was coming loose from the cones. I would have sworn that the voice coils were warped and touching the magnet cores.

I have had this before. The speaker has to be re-coned, or the surround has to be changed. There are a fair number of places that specialize in speaker driver rebuilding. The cone or the spider is off centre.

As the drivers age, they can go off centre. Some people suggest turning them around in their mounts, but this does not properly fix the problem.

When rebuilding a driver, I would have both re-built at the same time. This would insure that that they are matched.

The other solution is to call the JBL rep and order a new driver.

The fault you are having is common on many types of speakers. We send out speakers for rebuilding for our clients.

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JANA _____

I recently found a very clean pair of JBL L19 speakers. These speakers look new.

Before buying them, I examined the speaker surrounds thoroughly. All of them appear to be in perfect condition.

I took them home and hooked them up.

They sound very good, but I am hearing a slight rattle coming from one of the woofers. The rattle is not very loud at all, and in fact is almost inaudible most of the time. But you can definitely hear it if you are listening to certain things like a bass-heavy radio announcer's voice or a soft piano solo.

The woofers on the JBL L19's have a bowl-shaped piece of paper glued to the center of the cone. I have verified that the glue is solid all the way around; I have even run a very fine bead of glue left over from a speaker surround kit all the way around the bowl, but the rattle persists.

I can make the rattle go away if I gently put my finger on certain places in the center of the woofer cone. I can make the rattle worse if I put my finger on the surround, near the top of the speaker.

One more thing: I can hear a slight rubbing noise if I gently push the woofer's cone back and forth on the top half of the speaker. I do NOT hear this rubbing noise if I push the cone anywhere on the bottom half, and I do NOT hear the rubbing noise if I push both the top and bottom halves at the same time (in other words, if I push the cone in a "balanced" way).

I have verified that NOTHING is touching the back of the speaker; no wires, no insulation or anything else.

I am suspecting that maybe the spider is out of round or off-center, or maybe the voice coil is off-center.

What can I do to further diagnose, and then fix, this annoying problem?

Hi Arfa! All is well here, thanks - hope the same with you! (Dinky little drive belt continues to work perfectly!)

Anyway, regarding our Guitar String friend (that anyone should be so quick to support me when U No Hoo is flicking his little calumnies my way!) - as I said above: On my machine (which is new, so it don't go back all the way to the Big Bang) I have only one former entry which shows another instance of him crossposting a request for advice and no sign of a response of any kind to the 4 replies he received:

I speak as I find...!!

Fair enough , Keith. I would have to say that it was possibly an oversight then, because as I said, I have typically found him to be a responsible poster, definitely not in the class of 'spammer' or 'troll' ...

Glad you're all well, and the belt is still ok. Fleetie pops in over here from time to time. I'll have to try to find the (computer) time to pop over there again soon for a chat with all you guys.

Arfa

I've known EADGBE to be anything but a spammer. Maybe it's you who should piss off...

Who the f*ck cares - I have clear evidence that he's a twice a year blow-in wanting free advice and obviously doesn't consider it ill-mannered to smear it all over several separate newsgroups to get what he wants and without a word of thanks. Look at the pic:

Work it out for yourself....

Delete 'spammer' and insert 'crossposter' if it makes you feel better - usenet tosser, either way....

Maybe it's you who should

From ukra - the only group I subscribe to? (See also in the pic...)

Stop and have a little think, YTC - you stop crossposting here and I don't even *see* your silly posts...

(Yes, my replies are also crossposted - how TF do I know where you are posting from...???)

Maybe your news server just didn't see his reply or it didn't get crossposted? I see a few regulars in that reply from s.e.r.. I know that EADGBE isn't a spammer / Troll as well. If you upset because it is crossposted, create a filter. Theres no need to get angry about it.

Now to get this back on topic, Have you tried moving the voice coil in and out by hand to feel if it it is dragging at all? I'd tend to agree with the others that the cone might be out of alignment a bit.

Mike

"Michael Kennedy" wrote

Angry at newsgroup posts? Oh, I don't think so....

Please point to where my original response is incorrect:

"According to my reader, the last time this crossposting clown posted in ukra was 18/05/07 to ask for free advice with questions about more dodgy old gear, splashed across a different spread of newsgroups and then failed to acknowledge the bunch of helpful replies he received...."

And then consider directing your advice to the root cause - ie, the crossposter himself who, incidentally, responded to me with this little gem:

"Then you don't know how to read your reader, asshole.

If you ACTUALLY did the research you claim to have done, you will find that I have consistently and publicly thanked the people who took the time to help me."

When the clear evidence:

indicates that a) I did do the research, b) your paragon failed to thank anyone at least on that occasion and c) is, in fact, a crossposting little gobshite who doesn't brook at dragging half Usenet into sorting out his problems for free if, when and as he feels like it....

Hey ! I've never seen you getting this worked up Keefy baby ! Those good 'ol Aussie boys on ukra been giving you lessons or summat ? d;~}

Arfa

Keith,

It seems to me like you are digging yourself a deeper hole with every reply.

From what I've read in the sci.electronics.repair newsgroup, EADGBE does not qualify as a spammer and prior to his response to you, thanked contributors and kept things civil.

The record on this particular news thread speaks for itself.

Bob