Small problem with K2 S9800 Need information

[Loffen]

Hei Guys

Last weekend I did arrange a Norwegian AVforum meeting at my Cafè
Everything vent fine until we tested my setup ( K2,Parsound C2,D3 and JC1 ) we where playing loud and went up to 0 db on the C2.

We where monitoring the elements on the K2s and there was no problem the first 20 seconds,but the it started to smell burnt and signs of smoke where comming from the speakers

Why can you see from the picture below....

The speakers are still under warranty,how would JBL deal with this problem ?

[BMWCCA]

They'd most likely tell you you had some form of distorted signal being supplied by your amp. The old JBL here in the USA would have said that and then fixed it anyway. I have no idea what they'd do today or especially what they'd do through their European distributor. I suspect they'll fix you up. They need more customers like you!

I'm sorry to hear your tale, and truly jealous since there's not any place I know of where I can actually even go to hear a pair within 500 miles, if that, much less buy one, if I could afford to. The last price I saw in the USA was for the SE at $30,000/pair.

[Loffen]

Thanks for the fast answer,you are most welcome to visit me in Norway any time

How can a distorted signal do this ?
I had 3 of the Norwegian "guru's" in the room when this happend and one of them was controlling the volum,nobody heard any distorsjon what so ever

[Loffen]

By the way,it was two resistors that was burnt (33ohm 5w) the same in both x-overs on the HF board.

[oznob]

OUCH! Any chance you had an issue with the (+) and (-) speaker wires touching? Most modern amps will shut down when that happens but not always and bad things usually happen as a result! Some distortion may not be audible especially at high listening levels. If it were me, I would have your amp checked by a qualified technician before I used it again. You might want to hit up member 4315B about who would be the "right" people to contact at JBL.

Good luck!

Mark

[Loffen]

Thanks Mark

The amps are good (The JC1 is a monoblock) and since it happend to both speakers at the same time we can take out the speaker cables (Kimber Bifocal xl)

I will see if I can get in thouch with 4315B

[pos]

You might want to hit up member 4315B

I think you are talking about member 4313B here.
He would not trade his 066 for a 077

[Loffen]

Thanks pos

I have sent him a PM

[Robh3606]

Were they biamped or the Biamp switch in the correct position?? Could be just too much power.

Rob

[Loffen]

Hei Rob

No,they where just Biwired,the selector is in the "Normal" position

[Andyoz]

How big was the room and how loud were they. You really must have been on the juice to fry them

[Loffen]

Pretty big,about 80m2.

The JC1 is 400w in 8ohm,however they where messured by Steriophile to around 570w in 8ohm
You can see the setup to the left in the picture.

[Loffen]

one more pic

[BMWCCA]

I'm pretty sure it was the speakers rejecting your pants!

I've seen plenty of tweeters fried from not enough power to produce a clear signal, but that's not really the case with your problem. I have personally had an 075 blown by what JBL said was likely a "high frequency oscillation". To my non-engineer mind, it would seem the same problem could cause the crossover to fry as easily as the tweeter. It wasn't too much power (Kenwood receiver in 1970) but just a non-musical signal. In your case it looks like the crossover acted as a circuit-breaker to protect the tweeter. From my past experience, I'd have the amp checked. I doubt it was too much power but the same signal to blow both sides must have come from somewhere upstream. Of course it could well be bad resistors but how likely is that to happen on both sides at once? I'm no help but still curious to hear what you find out. Good luck. Beautiful speakers.

[Loffen]

He,he,he I am NOT the "gay" in the picture

The amp where used after the brakedown for several hours on other speakers with out any problem and the Amps are imported from the US so the dealers here in Norway will not thouch them

So it could be that the resistors work as a "fuse" protecting the element,strange I have never heard of that before..