Distortion on 435Be

[cooky1257]

Hello all,
Do any of our resident experts have any opinions on what could give rise to distortion in the 435Be section of some K2 S9800's?
Crossovers have been swapped and the fault appears to be the speaker driver.The owner assures me they are well loved and haven't been overdriven.
I've heard surround creep mentioned and also cap foam coming unstuck.
The owner is in the UK and approved service centres are very very very thin on the ground.

Any suggestions/advice would be most welcome.

Thanks

Cooky

[Andyoz]

Hi Cooky,

I have no idea what the problem is but how do you find the 9800 sound. I have never heard them but hope to own a pair one day???

[cooky1257]

Hi Andy,
I'm not on the receiving end of the S9800's so can't comment-I'm just trying to help someone out.

Cooky

[Lee in Montreal]

I suppose that if the driver was owered directly off an amp, with a cap to filter out lower frequency, it would easily help find the problem.

[Andyoz]

Hi Andy,
I'm not on the receiving end of the S9800's so can't comment-I'm just trying to help someone out.

Cooky

I was hoping you might have heard them first hand?

[Robh3606]

Try doing a slow low power sine sweep. Might help you pin point it or at least give you a range of frequencies where the problem is. Could be as simple as the cover screws being loose or a wire.

Rob

[cooky1257]

I've suggested he check the bolts too-without over-tightening them
I may just get him to remove the driver and send it to me so I can give it a clean/recharge the ferrofluid/sweep etc.

Thanks chaps.

[cooky1257]

The chap with the distorting 435 has sent me these pics of the unit in question.

No ferrofluid but lots of flakey trim in the gap..

[JeffW]

What is that? Looks like plating coming loose.

[Robh3606]

Crap that sure looks like the plating. In the gap as well yikes! Those are in 9800's can't you get a new driver through the waranty?? Couldn't hurt to ask that is a manufacturing defect. You could also get a 2431 core and just change out the diaphram and cover.

Rob

[cooky1257]

Shocking isn't it?
The other thought that came to mind was they'd been opened and the crap from the trim had headed straight for the gap...

The 2431 cores idea is a good one, I'm told the speakers are out of warranty
and the dealer is attempting to contact the JBL rep over the holidays.

[Mr. Widget]

The 2431 cores idea is a good one, I'm told the speakers are out of warranty
and the dealer is attempting to contact the JBL rep over the holidays.

If the drivers are from a K2-S9800 and they were purchased through a legitimate dealer, I would think they'd be covered even if past the 5 year limit.


Widget

[Titanium Dome]

That picture is frightening and somewhat disconcerting. The 435Be is in other product as well.

If the driver hasn't been tampered with in some way, what might account for this degradation? In addition to manufacturing defects, are there usage or environmental factors that might cause this?

Though I'm not right on the Pacific Ocean, it's not far away. I wonder sometimes about the effects or marine air on some of my equipment. Is the owner living near the sea?

[Mr. Widget]

Is the owner living near the sea?

Ever look at a map of Britain?

I don't see corrosion, it looks like an original manufacturing defect to me.


Widget

[Robh3606]

Though I'm not right on the Pacific Ocean, it's not far away. I wonder sometimes about the effects or marine air on some of my equipment. Is the owner living near the sea?

It has nothing to do with that. It's a plating failure on the NEO magnet. That's one of the reasons it's all in the gap as well. I am suprised the top plate has not shifted.

It could be from a bad plating batch on the NEO magnets so it could be in 2431 as well. Could be an isolated incident as an example the magnet was not prepared properly. If you took masking tape and put it on the area that is peeling it would take most of the "loose" stuff right off.

Yeah know what stikes me is odd is the finish on the magnet. The ones I have are black yet this one seems to be silver almost looks like nickel plating?? I have to check my drivers when I get home. Here's picture of the one I had the shifted top-plate on. You can see the black magnet sandwitched.

Rob