PDA

View Full Version : Small problem with K2 S9800 Need information



Loffen
06-11-2008, 07:37 AM
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 :applaud: 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 :blink:

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

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

BMWCCA
06-11-2008, 07:52 AM
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
06-11-2008, 08:03 AM
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 :confused:

Loffen
06-11-2008, 08:08 AM
By the way,it was two resistors that was burnt (33ohm 5w) the same in both x-overs on the HF board.

oznob
06-11-2008, 08:44 AM
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
06-11-2008, 08:51 AM
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
06-11-2008, 09:03 AM
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 :D

Loffen
06-11-2008, 09:14 AM
Thanks pos :)

I have sent him a PM

Robh3606
06-11-2008, 09:16 AM
Were they biamped or the Biamp switch in the correct position?? Could be just too much power.

Rob:)

Loffen
06-11-2008, 09:22 AM
Hei Rob

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

Andyoz
06-11-2008, 09:26 AM
How big was the room and how loud were they. You really must have been on the juice to fry them :o:

Loffen
06-11-2008, 09:34 AM
Pretty big,about 80m2.

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

Loffen
06-11-2008, 09:36 AM
one more pic :)

BMWCCA
06-11-2008, 09:54 AM
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
06-11-2008, 10:05 AM
He,he,he I am NOT the "gay" in the picture :wasnt-me:

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 :banghead:

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

Valentin
06-11-2008, 10:45 AM
The speakers are still under warranty,how would JBL deal with this problem ?

They have a DIY fix it your self policy probably they could send you new crossovers

here is the link

http://www.jbl.com/home/product_support/doityourself.aspx?prodId=K2S9800DG&product=K2%20S9800%20(Dark%20Gray)&Language=ENG&Country=DK&Region=EUROPE

please keep us posted if this service does work
hope it does

if you get your new crossovers and you don't have a need for the old ones please don't throw them away i will gladly adopt them

Loffen
06-11-2008, 10:57 AM
Thanks Valantin

That was great news,I will for sure give it a try :)

Valentin
06-11-2008, 11:02 AM
JBL K2 S9800/K2 S9800SE

JBL Loudspeaker Troubleshooting/Repair Tips

Most customers prefer to do simple loudspeaker repairs themselves. By following the steps below, a majority of loudspeakers can be returned to
their original factory performance with minimum effort. Choose the example that best describes the problem you are experiencing.

Problem 1: No sound or distorted sound from one loudspeaker in a pair (or set)

Connect the dead/distorting loudspeaker to a different amplifier channel (one that had a functioning loudspeaker connected to it). If it functions
normally, the problem is not loudspeaker-related. If the loudspeaker still makes no sound or sounds distorted, a wire may have become loose
or disconnected, the network (also known as a crossover) may be defective, the drivers (woofer, tweeter, etc.) may be defective or, in very rare
cases, all may be defective.
Refer to the wiring diagram and exploded view below. The network is a small circuit board found on the inside of the terminal cup, or mounted to
an inside wall of the enclosure. It sends low-frequency sounds to the woofer, high-frequency sounds to the tweeter and, if applicable, mid-frequency
sounds to the midrange driver. Make sure all wires are secure and connected. Look for components on the network that look burnt, “bulged,”
or abnormal. If everything looks normal, connect the network to the drivers from another matching loudspeaker. MAKE SURE you attach the
correct wires to each driver – mid- and low-frequency sounds can damage the tweeter! If there is still no sound or distorted sound, the network
is defective. If there is clean undistorted sound, the drivers are defective.

Valentin
06-11-2008, 11:17 AM
may be its time for an upgrade if your 9800 are not the Special Edition

JBL doesn't make the K2 S9800 anymore thy only make K2 S9800SE
the only difference is the crossover hope you are in luck and you get the new xo


those XO are made by Elytone in china

http://www.elytone.com.tw/group-1.asp

here is the link where clearly they have a picture of them

Loffen
06-11-2008, 11:27 AM
You are right Valentin, I did try to order the crossovers but they where not in stock.
And the form I was directed to only works in the US so I will call them to morrow,wish my luck :)

Loffen
06-11-2008, 12:06 PM
Yes it was loud,but noting like the Swans/SVS/Yamaha Z11 setup playing in 11.6 (!!!) surround.
We had peaks over 127db :rockon2:

subwoof
06-11-2008, 06:44 PM
Posting pictures here is fair game to critique - simply *love* the replacement system in the background of the last picture...:)

As for the resistors burning, they simply were overpowered. I suggest removing the HF drivers ( I thought the K2 had the 2" 476 ?? ) and see if they are / not damaged. It's also possible they were part of the zobel filter on the LF section - without a schematic I can't be sure.

One thing I have found amusing is that when a resistor's power handling is measured by a manufacturer, it is with the full length leads and in open space but when they are installed on a circuit board the leads ( they ARE heatsinks! ) are cut OFF and it's usually put close to other heat producing components AND in a space with restricted airflow..!

These scenarios mean the resistor should be derated accordingly yet EVERY speaker manufacturer misses this point! I did engineering for a D.O.D. company and we had to derate every component based on the worst-case scenario and you bet that NASA does this for everything that's whizzing above you in orbit...!

IF your drivers escaped damage, take the crossover board out, bring it to a decent electronic technician and have him install the same value resistors but one size larger ( those look like 5 watt ) and space them ( staggered if need be ) OFF the board by 1/2 to 3/4 inch.

The vast majority of burnt resistors I see on passive crossovers is from harmonic distortion when the HF component sees the harmonics from clipped lower frequencies and is forced to reproduce them too. This is true for ALL the bands in a multiple-way system EVEN if biamped since most high-end JBL's have elements in circuit at all times!

SINCE you had plenty of power, ( and ran it up to "O" ) I suggest you look at the signal source and see if it overloaded the preamps input stage ( VERY common problem with high end CD players ). Install / make a 12db pad for these demo's and next time, obey the laws of physics and common sense.

That system was *tiny* for that large space and forcing just 2 compression drivers and 4 cones to fill it, and pound it at 127db, meant a sure-fire recipie for failure.

As the germans say, this speaker suffered from amplifier mitknobbenpoken.

sub

Allanvh5150
06-11-2008, 10:43 PM
I would have to fully agree with Sub on this one. Those two resistors are in the signal path for the driver and any distortion or "overloading" will fry these in no time flat. A good upgade would probably be to put two 10 watts in their place, mounted clear of the board of course. Although in a similar application I have seen these resistors get so hot that they melt the solder connections and fall off the board. Common sense always prevails.

P.S. Were anyones ears bleeding? :)

pos
06-12-2008, 12:02 AM
( I thought the K2 had the 2" 476 ?? )

forcing just 2 compression drivers and 4 cones to fill it, and pound it at 127db, meant a sure-fire recipie for failure.

Hey Sub, is it too early in the morning? It looks like you are confusing the K2 and the Everest 2 here ;)

Loffen
06-12-2008, 02:22 AM
Thanks guys,a lot of input here.

First the K2 was never played at 127 db, the other system was,I did say that it was loud but I did never mention the sound quality of that system:D

"P.S. Were anyones ears bleeding?"
Nope,we Norwegians are made for this, one guy did fall a sleep during a movie played at 120db.

I will come back to you when I know what the dealer wants to do.

Hoerninger
06-12-2008, 06:01 AM
P.S. Were anyones ears bleeding?

It is just like with radioactivity, which you can't feel.
It is a question of strength and duration.
The trouble is that a a high quality speaker has little distortion and you do not feel how loud it is.
__________
Peter

subwoof
06-12-2008, 07:11 AM
I had a engineering report somewhere on the "new" 2" JBL Nd driver from 1990 or so that showed the internal closed magnetic path ( 475-476 ? ) vs the external path ( 2450 ) even though they were otherwise the same.

The diaphrams were the 2445 with the (new) aquaplas coating and a customer sent me new ones in the box to install into his old alnico 375's and I happened to have a pair of 2450SL ( from the DMS-1 ) here and when I compared the dia's, they were identical.

And those are the full 4" coil not the 3" of the 2435,31,435 etc.

When I was at the JBL factory ( 30 days before the quake ) I saw the K2's being assembled and packed and this was long long before the 3" drivers were made.

SO I guess there are many versions of the "K" series - maybe a tech sheet / data spread sheet of years, components, etc would be nice like the one that's been posted for the 43XX monitors.

Since we poor americans do not have easy access to see / buy / find or even listen to the newer JBL's it would help us old timers get up to speed...

sub


BTW the resistors are part of the network that pads the driver's output down to match the rest of the system and are not considered "fuses" or safety devices. They burnt because they were in the line of fire..:)

Robh3606
06-12-2008, 07:17 AM
A good upgade would probably be to put two 10 watts in their place, mounted clear of the board of course.


Why are you guys second guessing the engineering?? Why not just turn it down. Better the resistors than the driver. Those networks, resistor wattage ratings, are not set-up for high SPL SR work and should not be pushed to those levels.

Rob:)

Loffen
06-12-2008, 07:26 AM
Posting pictures here is fair game to critique - simply *love* the replacement system in the background of the last picture...:)

Yes they work hard to get the new DeWalt High end system out on the marked here in Norway :D

The system you see in the backgound can also be operated under it's own battery power !! :applaud:

The sound is "unbelivable" :barf:

Below is a better picture....

Ian Mackenzie
06-12-2008, 01:32 PM
You might want to post a thread over on diy audio for John Curl to comment on the ML.

As to the incident in hindsight it might be better to look at biamping.

In a large room like that you really have no idea how much power you are using.

The difference between 200 and 400 watts is only 3 db and I know from personal experience you really need the 400 watt amp on the woofers and a really clean 100 watt amp on the horn for a reslistic improvement in dynamic range.

Ian Mackenzie
06-12-2008, 01:41 PM
You might want to post a thread over on diy audio for John Curl to comment on the ML.

As to the incident in hindsight it might be better to look at biamping.

In a large room like that you really have no idea how much power you are using.

The difference between 200 and 400 watts is only 3 db and I know from personal experience you really need the 400 watt amp on the woofers and a really clean 100 watt amp on the horn for a reslistic improvement in dynamic range. Pushing a large amp hard is looking for trouble.

Years ago I went to a demonstration by Rank (the importer of Altec consumer) at a dealers show room of the full range from model 19 down.

The played the model 19 last and loudest on a hugh Sansui power amp that was rated at least 300 watts.

It was seriously loud and yes they blew both speakers:banghead:

Loffen
06-12-2008, 01:59 PM
You might want to post a thread over on diy audio for John Curl to comment on the ML.

:blink: Uhuu..... In Norwegian or English please :o:

Ian Mackenzie
06-12-2008, 03:26 PM
I think you understood my post perfectly well.

Why people come here for answers when they do something really fucking stupid is beyond me.

Loffen
06-12-2008, 03:34 PM
I think you understood my post perfectly well.

Why people come here for answers when they do something really fucking stupid is beyond me.

Well I did not.

I was really asking where I could find "diy audio" and what you mean with "ML"

But thanks for the kind words anyways :)

Loffen
06-12-2008, 03:44 PM
Thanks Grumpy

Valentin
06-12-2008, 03:47 PM
ML Mark Levinson John Curl did some amps with them before Parasound

ML9 is one of them
i own one it sounds nice and it is the most powerfull 100 watts y have heard

Ian Mackenzie
06-12-2008, 08:46 PM
I think you will find that those resisters are put there by the designer as the "fuse" and are rated for such an event. I mean that is what I would do. If you replace them with large resister it would most certainly void the warranty.


Per my earlier post:

""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 :applaud: and went up to 0 db on the C2.""

I am not sure if the amp has meters but is it almost certain that you hard clipped the amp on peaks if the meters were reading 0 db.

Hopefully the voice coil is not damaged. Very expensive to replace.

Its a shocking thing to abuse such a fine loudspeaker.

BMWCCA
06-12-2008, 09:55 PM
My vote for the culprit is still your $6000 Taiwanese amps. ;) I've played lesser JBLs far louder for far longer with less-powerful USA-made amps with no issues. I have to think you were either clipped, too hot on the input, or sending non-musical material through the system in some fashion. I don't see anything about protection indicators for the JC 1, like the IOC I'm used to on my Crowns. Is there anything in that system to tell you when you've clipped it?

Truly sad to see such problems with an obviously well-though-out and well-configured system. I just can't believe you played it loud enough to cause this failure by sound level alone.

grumpy
06-12-2008, 10:31 PM
Speaking of blowing smoke ;) ...

"After speaker levels have been set up ... a volume setting of “0”
will correspond to THX reference level, a sound pressure level (SPL) of 75 dB,
measured with the standard C weighting curve."

"The C2 Controller’s volume can be adjusted over a 106-dB range (–90 dB to
+15 dB). Once the C2 has been calibrated for your listening room, amplifiers,
and speakers, the sound reaching you when the volume is set at 0 dB will be
just about the same level you’d hear in a THX-calibrated commercial movie
theater."

Depending on how/if the speaker levels were set (in a large room, this could
conceivably be more gain than in a more normal locale), "0" could mean
signals were passed from the preamp in excess of what it would take to
cause amp clipping (potentially, up to +15 dB of gain is available... which would
clip even the preamp with a 2Vrms input, which should represent a -very- loud
passage sent from a CD player output).

In a smaller room, the calibration (gain adjustment) for THX levels (loud, but
not insanely so) would not drive the speakers so hard with the C2 set to "0".

Point is: a volume setting of "0" on the C2 pre isn't necessarily unity gain, it's offset
+ or - based on a room calibration. My old Kenwood Sovereign receiver works the
same way (we usually run it at "-9" and it's plenty loud for me).

That at some point, the equipment chain was pushed beyond it's intended use is clear.

Hope this helps or at least makes sense. -grumpy

Loffen
06-13-2008, 01:10 AM
Hei Grumpy,I am not sure that the system was pushed beyond its limits however.

The Parasound C2 is a surround receiver and it was set up for a smaller room,the front speaker gain was (and still is ) set up at 0 db (you can place the gain anywhere between -15 and + 15 db ) the same is true for the D3 CD/DVD player.

On the JC1 they was set in the high bias mode.

And last the C2 was running in a "Bypass" mode,which does not add any treble or bass and do send the signal almost directly through the C2.

I do not think this i any kind of abuse of the speakers,it would have been if the gain was + 10 db and the volume was set at + 15 db but that is not the case here.

And this is taken from the instruction manual :

Amplifiers/receivers of 100-500 watts will ensure optimum system performance.

There is no effective limit to the power handling capabilities of the project K2 S9800 loudspeakers when driven by consumer audio amplifiers.
No damage will occur when used with high powered components.. and so on

Rolf
06-13-2008, 01:39 AM
Hey! I have melted some x-overs to. (Not JBL's) And that was due to over powering them.:o:

Shit happens sometimes.

Regarding comments of "how stupid you are", "over powering", don't care about these posts.:barf:

Welcome to the "loud JBL sound":applaud:

Loffen
06-13-2008, 02:27 AM
My vote for the culprit is still your $6000 Taiwanese amps. ;) I've played lesser JBLs far louder for far longer with less-powerful USA-made amps with no issues. I have to think you were either clipped, too hot on the input, or sending non-musical material through the system in some fashion. I don't see anything about protection indicators for the JC 1, like the IOC I'm used to on my Crowns. Is there anything in that system to tell you when you've clipped it?

Truly sad to see such problems with an obviously well-though-out and well-configured system. I just can't believe you played it loud enough to cause this failure by sound level alone.

Maybe the Taiwanese Xovers in the K2s just was not up to it :D
Just kidding (but they are made in Taiwan)

There is a protection circut in the JC1 but you will not get any indication.
The only indication you will get is if it overheats.

Loffen
06-13-2008, 02:33 AM
Hey! I have melted some x-overs to. (Not JBL's) And that was due to over powering them.:o:

Shit happens sometimes.

Regarding comments of "how stupid you are", "over powering", don't care about these posts.:barf:

Welcome to the "loud JBL sound":applaud:

Takk Rolf

It is nice to know that I am not alone :)

As far as I know there is 4 pairs of the K2 S9800 in Norway and the set at Neby was fried to just the same as my crossovers !

Rolf could you tell the guys who Neby is ?
I know that it is a post here showing pictures from his "collection"

Loffen
06-13-2008, 02:47 AM
I did find Rolf

Here is the link :

http://www.audioheritage.org/vbulletin/showthread.php?t=20265&highlight=erling+neby

grumpy
06-13-2008, 06:53 AM
Hei, Loffen,


I am not sure that the system was pushed beyond its limits however.

at the very least, the speakers were (end of the chain). :) For SPL-demo use,
perhaps resistors with more thermal capacity would be useful (as has been mentioned)
... to raise the "effective limit".

In-home use, it seems like the designed/implemented resistor type should be fine.

It -is- sad/disappointing that these fine speakers got popped.

jan_slagman
06-13-2008, 03:32 PM
Hi Loffen,

The same happened to my Cambridge Audio TL 200's (big English transmissione line loudspeakers ) wayback in the early Seventies.
At that time i had a Dynaco PAT 5 preamplifier and a Dynaco ST 410 power amplifier. Unfortunately i forgot to switch on the Dynagard, which was the amplifier's power limiter.
I can recall i played the Abba song Arrival and i believe they were using bagpipes in that song. At a certain moment there was a continuous tone and i played that with a high amplitude. My neighbour who sat next to me all at once knocked me on my shoulder pointing direction left loudspeaker. My goodness, it looked like someone was sending smoke signals through the transmissionline's duct. After that event there was an unbalance between the loudspeakers due to burnt crossover components in the left loudspeaker.

Kind regards,

jan Slagman
The Netherlands

Zilch
06-13-2008, 04:03 PM
Good point -- does it still play, or not?

Are we just crying over spilled magic smoke here? ;)

gtimbers
06-13-2008, 05:25 PM
Oops! Too much power. Those Metal Oxide resistors sound very nice but are not as robust as the wire wounds we typically use, I am not in the office today so I am not sure exactly where in the circuit those parts are. I would expect your dealer/distributor to take care of the problem, but if you are handy, I can send you some replacement resistors. It will be a lot less trouble for everyone that way. I will send some wire wounds so the problem doesn't happen again.

The Metal Oxide film resistors will barely handle their rating and then pop quickly. The wire wounds will take about double their rating for short periods. They just get hot and start burning the board and surrounding parts but they usually hang in there.

The K2 was not designed to play extremely loud for any period of time. I always have a decision to make regarding the best possible sound, cost parameters, and robustness. We have had no reported power handling failures with the K2 so I am comfortable with my choices on this unit. I'm sorry you had a problem with yours. We can beef it up a bit and you should be O.K. after that. You can send any address information to Giskard and he can get the information to me. I don't view the forum regularly,

Regards,

Greg

subwoof
06-13-2008, 06:09 PM
Back when I made some "poof-proof" networks for the installs that had an impossible access, I used the 25 watt adjustable resistors ( see picture ) that we actually mounted to a panel with large bolts.

The drivers were 2482's so we wern't concerned about the occasional clip BUT fire was a real threat so into the metal boxes they went...:)

Now I use them and the 50-70 watt flat types that were used in very large wiper motor speed controls by some detroit company. Found them in 4,5,7,8,20 ohm in stacks of 10 for a buck each....:o)

sub

Valentin
06-13-2008, 07:05 PM
thats that

nice ofer take it

or wait a long time for replacements.

Loffen
06-14-2008, 04:09 AM
Thanks Guys.

I will of course take Mr Timbers kind offer, there is no problem for me to replace the resistors.
Giskard can you please send me a PM so I can give you my address ? I do not know your username on the forum.

I did also receive an answer from Mr J.Curl it was short but he did say the same as Mr Timbers.
(I rearly use "Mr" in front of anybodys name,but here I am talking to two of the persons that have all of my respect and admiration :))

I will add a picture or two of the crossovers when the work is done.

Loffen
06-14-2008, 05:33 AM
Good point -- does it still play, or not?

Are we just crying over spilled magic smoke here? ;)

If you where thinking of the K2s they where not played on after this happend,however the resistors is placed in a paralell configuration,in one crossover they was almost up to specs, in the second crossover one of the resistors where clarly burnt up the other was out of specs.

Loffen
06-14-2008, 08:34 AM
Just a short note, I have got hold of Mr Giskard and my address is forwarded.

Thanks guys !

oznob
06-14-2008, 02:26 PM
Just a short not, I have got hold of Mr Giskard and my address is forwarded.

Thanks guys !

Hey Loffen, if he hasn't got back to you, Giskard's forum name is 4313B. It is a very kind offer form Harman/JBL's Chief Engineer!:applaud:

Loffen
07-08-2008, 01:51 AM
Just a short update.
I got the resistors from Mr Timbers yesterday and I will replace them later this week.
I will add a picture or two when it is all done.