Help Tweeter Dome Broken What To Do ?

[misterdoggy]

Sorry to hear that many people are having problems with the diamond tweeter. As part of this discussion, let's not forget that B&W spent *years* developing and testing this new tweeter. I'm sure that their research and development effort included some form of stress testing on the new tweeter material. I don't think that they would release the product to market if it was known that the tweeter dome was too fragile to be used as intended.

Mj

Everything can get improved.

[Djas_Puhr]

Very true. Let's hope that B&W spent their time improving the diamond dome before it went to market, without relying on customers to do their durability testing for them. For now, I want to give them the benefit of the doubt.

Anyways, it is a shame what happened to your 802D's. I hope that the repair process is as painless as possible for you misterdoggy.

Mj

[RNKC]

A cheap fuse might compromise sonic quality which none of us would want, particularly in an 800 series setup. But, why not design the whole crossover to blow / melt in a catastrophic situation? I'll bet it's a whole lot easier to replace that part and likely much cheaper than replacing that precious diamond tweeter. Let's face it, the primary purpose of buying an 8xxD is to get the diamond tweeter. Otherwise the world could have just stayed with Nautilus.

I submit that if the diamond tweeter is as fragile as some in this thread are making it out to be, then the whole thing could be considered a design flaw. This places the blame squarely on B&W. In fact, if this was a car and not a speaker, I'll bet there would have been either a service note issued to all the dealers or even a recall notice to all the consumers who bought the product.

Several people in this thread have noted the fragility of the diamond tweeter. If they are all correct, there is something not right about that tweeter. B&W needs to own up here.

[ZX10 Guy]

Well, I added my 2 cents in as I've studied materials properties in college for my engineering degree. We went over processes like vapor deposition as I discussed and also using powder metallurgy to create parts without the expense of forming the part from a solid piece of said material. People kept alluding to the fact that they think the diamond tweeter is a solid piece of diamond material hence why they kept assuming something is wrong for it shatter given the possible scenario in this thread. To make the diamond tweeter out of a solid piece of diamond, you're going to be paying a heck of a lot more than what you're paying now.

With all vapor deposition processes, there is always a chance where the entire dome isn't uniform or some areas might have more material than another. This could be just a case of a manufacturing defect. Also, I'm not privied to the design parameters of the tweeter or the performance data so I can only speculate that with a high frequency burst, the dome might have oscillated in a manner not within the intended operating parameters of the tweeter. Remember, the diamond tweeter is going to be stiffer than aluminum. Aluminum can deform and flex much better than diamond.

Had it not been for a source component failing added to the mix, I would agree that B&W should cover the repair of the tweeter. But because we have the variable of a failed source component that could have caused the damage, it's not so clear as to who is ultimately at fault. This is part of the reason why I only buy trade ups or used equipment that has a transferrable warranty. Other than that I only buy new or demos.

[misterdoggy]

This is part of the reason why I only buy trade ups or used equipment that has a transferrable warranty. Other than that I only buy new or demos.

ZX10 Guy

I hear you about not buying used equipment and I could have bought a new Lexmc12b for $7800 or this one used Version 5 for $5400. I should have gone for the new one and spent the bucks. Heck its $9k+ normally new.

I'm not sure what the cause, but something can happen to anything at anytime. Now I have to live by Murphys Law and make sure all the bases are covered.

Voltage Regualtor and Line Conditioner are on this weeks shopping list for me.

I just bought a Furman Ar 2306 voltage regulator and will buy a Shunyata hydra 8 line conditioner. This means 2 stops of protection against surges and variation in current. This takes out that possibility.

Also the Lex has a new updated power supply, which by the way might have been the problem. Why would they update the old one to a new one.

[PewterTA]

Hey, you have to look at it this way (I think)...you could've bought the new Lex and not had this happen, or you got this used Lex, blown tweeter, which you are replacing, and a new PS in the Lex...all for LESS than what the new LEX would've cost you. So you are still under par.

Just trying to look at the positive I guess.

...and have you tried Duct Tape?! I bet that would fix it! :rofl:

[autio]

Do you think Lexicon would have covered the cost of fixing the tweeter if it was purchased new by you? I certainly dont think it would be covered onder their warranty.

[misterdoggy]

Do you think Lexicon would have covered the cost of fixing the tweeter if it was purchased new by you? I certainly dont think it would be covered onder their warranty.

I've heard stories about components causing other things to break and the company foots the bill for both.

I imagine it would have to be a large company. However, Lexicon is now a Harmon Kardon company so they got the bucks.

[Gump]

As unfortunate as this incident was it appears to me to be an isolated event. I know this was already mentioned, but I believe it needs emphasis.

There are numerous diamond owners that read and participate in this forum and it seems that if this was a widespread problem we would have seen at least a few other reports here. And I'm referring to 1st hand specific accounts, not general alluding to, "heard about several incidents of this sort of thing", type reports.

As disconcerting as this situation is for diamond owners I'm going to need to hear a few more detailed horror stories and their circumstances before hitting the panic button.

I might be naive, but I'm chalking this up to an aberration possibly caused by some faulty eletronics, until proved otherwise.

[misterdoggy]

I would like to think that this was an out of the ordinary circumstance. However, we can't ignore it either and we will have to wait and se if there are more like this.

If indeed it was out of the ordinary, then B&W should replace under guarantee. Perhaps some manufacture error. When there is adoubt should it fall on the consumer?

Even though the replacement cost is $1200 the manufacture cost can't be more than a few hundred. I will let you know how it plays out.

[autio]

I dont own b&w speakers (I like mine better) but recently I was a a dealer listening to a preamp I would like to buy through some d series speakers and I asked him if he thought the diamond series was an improvement worth the money and of course he said yes. He continued raving about them but said he thought they may be fragile because he said a customer recently had one replaced because of a abberation of some kind with his amp. I didnt think anything of it until I read this thread because he did say their was some kind amp problem. He did state that B&W replaced it but said it was at their discretion because it wasnt thought to be a speaker porblem But the speakers were very very new.

[RNKC]

doggy - I see from a few other posts that you obviously got your tweeter replaced / fixed. Just curious, what finally happened? Did you just pay for a replacement and have your dealer install it for you?

[misterdoggy]

Well I bought my speakers from some shady guys in East Germany and they took a month and a half to get the replacement. They are currently holding me up for an old bill which they reviewed and said there was still money due. I am trying to work it out. They did get the replacement.

Of course I didn't wait and bought one the same day in the USA. $1050 smackers

So I will have an extra lying around. I can either sell it or keep it in case something else happens. I mean its not everyday someone will be looking for a diamond tweeter so I don't think I could sell it.

[azazel]

The damage to your diamond tweeter looks like someone has poked it or knocked it. I do not believe it could be caused by an electrical spike or anything electrically. The diamond is formed as one piece, one crystal, using CVD. It is very thin and delicate. The motor voice coil assemply would not be capable of causing damage. There is a problem with early nautilus tweeters, which I posted on another thread and I will copy here too.

There is a problem with early nautilus tweeters where the foam surround that holds the dome/ voice coil assembly in place comes unstuck. It is only held in place with a self adhesive material. When it comes unstuck, the voice coil comes out of the gap in the magnet. This means it is not being cooled by the ferrofluid and leads to overheating failure. I would think that its output would be reduced as less coil is in the gap intereacting with the magnetic field which would mean the user is moor likely to turn up the volume causing more heating and result in failure. The foam surround was the same diameter as the outer bevel apperture on the older models but B&W have since modified it so that the foam is larger and held in place by the outer casing.

[iiaudio]

The damage to your diamond tweeter looks like someone has poked it or knocked it. I do not believe it could be caused by an electrical spike or anything electrically. The diamond is formed as one piece, one crystal, using CVD. It is very thin and delicate. The motor voice coil assemply would not be capable of causing damage. There is a problem with early nautilus tweeters, which I posted on another thread and I will copy here too.

I see this all the time with hi frequency drivers from all manufacturers. They can and will shatter if they get a large enough voltage spike.

[azazel]

I see this all the time with hi frequency drivers from all manufacturers. They can and will shatter if they get a large enough voltage spike.

Respectfully, rubbish. Perhaps you could provide some evidence and some pictures. Most high frequency drivers have aluminium domes, some have titanium, some have fabric. Neither will shatter. B&W are unique in using diamond for their tweeter domes so I would bet they are the only tweeter material capable of shattering in a domestic speaker. I would also bet that it is not possible to break the domes (except by touching them)however much electricity you put through the voice coil.

It puts me off buying the diamond series speakers as I like to listen loud and B&W speakers dont sound that loud due to the low distortion and the silencing of energy from the rear of the drivers. The tweeter has been made to be as light as possible so as to give fantastic detail, but this makes it easy to damage.

[quan325i]

I'm the latest victim of a blown tweeter. In my case, it's from a 801 Nautilus. A few weeks ago, one of my Krell 650mc monos blew. I switched everything back to my CAL MCA2500 and noticed that the tweeter was dead silent. Swapping between channels and speaker cables, it was confirmed that the tweeter was dead. I called Mike Sheehan at B&W yesterday and bought a replacment tweeter for $97 shipped. The tweeter seems easily accessible by twisting counter-clockwise gently after removing the magnetic grill. I'll update this when I get the tweeter.

QN

[BrystonFan]

I too must join this thread.
Shattered 804D2 tweeter right out of the box. :M
Guessing it was damaged during shipping.
I would hate to think it was sent from the factory in this condition.

I'm thinking it would be best to have the Dealer install the replacement on site.

[quan325i]

I received the tweeter from B&W yesterday and am ready to install but I can't tell which of the 2 terminals is positive or negative. Does anyone know? Is the tweeter unipolar? Thanks.

QN

[azazel]

I received the tweeter from B&W yesterday and am ready to install but I can't tell which of the 2 terminals is positive or negative. Does anyone know? Is the tweeter unipolar? Thanks.

QN

The diamond tweeter is different to the older aluminium ones but my experience with the old ones is this:

One of the terminals should be coloured red with a marker pen and this goes to the top. Its important to have the correct polarity as the driver will be out of phase with the others. Be very careful as its easy to damage them while fitting them. Keep the gauze cover on the outer housing while fitting to avoid touching the dome. Check the alignment of the four raised dots and make sure they go in the right place. Practice fitting the outer housing with the old part before you fit the new part.

[azazel]

HELP

Im having a streak of poor Hifi Luck. I just discovered the tweeter broken in my 802D. It looks like it could be fixed easily and is kept in place by 3 screws.

Anybody have any experience replacing this.

How delicate were the broken bits of diamond dome? Are they very thin? Did you try how easy it is to break one of the fragments?

[lawpoke87]

Just replaced one on my 803ds. The whole front assembly is actually replaced...not just the dome. Unscrew those screws and twist the assembly counter clockwise. The tweeter assemble is actually threaded and secured by the rod sticking out the rear of the tweeter casing. I found it easier to assemble by threaded the rod into the tweeter assembly because the connection wires don't twist this way.

[SugarmillMan]

804D tweeter damage

I'm sorry to hear about all of the the broken diamond tweeters. I too had the unpleasant experience of discovering a shattered diamond tweeter right out of the box.
I purchased a brand new set of 804D's from my local B & W dealer in Tampa, Florida. I took special care when opening the box so the the damage must have occured during shipping. My dealer fixed it immediately without charge under warranty. :T

I hope this won't be a regular recurring expense!

[iiaudio]

Respectfully, rubbish. Perhaps you could provide some evidence and some pictures. Most high frequency drivers have aluminium domes, some have titanium, some have fabric. Neither will shatter. B&W are unique in using diamond for their tweeter domes so I would bet they are the only tweeter material capable of shattering in a domestic speaker. I would also bet that it is not possible to break the domes (except by touching them)however much electricity you put through the voice coil.

It puts me off buying the diamond series speakers as I like to listen loud and B&W speakers dont sound that loud due to the low distortion and the silencing of energy from the rear of the drivers. The tweeter has been made to be as light as possible so as to give fantastic detail, but this makes it easy to damage.

Here is a 2" RCF compression driver from a EAW KF760. It received the signal for the low frequency driver (mispatch at the amp rack). A couple hits of the kick drum, and this is what was left.

[azazel]

Smartarse! But fair enough, you proved me wrong. Hardley a fair comparison though. Industrial PA system wired up by a fool compared to domestic passive loudspeaker wired up by the factory.

[caberxx]

Unfortunately, I too must join the list of those that have suffered from shattered tweeters. My 802Diamonds were only 3 months old when the first one shattered. B&W replaced it. A month later, the tweeter in the same speaker shattered again. B&W replaced it. Then, it happened a third time. This time, the dealer sent a tech to the house. They replaced the tweeter and the large capacitor in the high pass cross over. They also ran some tests on the resistors and found that two were faulty (couldn't get a consistent reading on them - varied from 1 ohm to 6). So they replaced those too. That was 2 months ago and so far I haven't had any issues. However, I've been quite reluctant to turn up the volume out of fear of doing damage - which is a real disappointment, because I do enjoy cranking it from time to time. Dealer first asked if I had a poor quality amp - I don't. Each 802Di is bi-amped with two Classe CA-M400 amps, so the power it's getting is clean.

[kking168]

I have the older 803D. The diamond tweeters have some grayish discoloration. Anybody else experience this?

[azazel]

Those broken bits of diamond tweeter, how delicate are they? Are they like broken light bulb glass? Or more fragile than that?

WHY is this forum soooo deserted?

[toddmorr61]

add me to the sad folks with busted diamond tweeter. At least I think so. Was playing my 800D rather loud yesterday as I was on the first floor and wanted to enjoy the music from upstairs. Mine is not shattered but does have a slight discoloration on the dome, almost like a faint shadow of a half inch long or so, and it is dead quiet. Switched L to R the speaker cables at the amp and no change, so it must be something in the speaker. MR and woofers are fine. I am driving the 800D with a 200w Rotel amp and the volume was at "11 o'clock" on choir music....so it was being driven hard but didn't think it was that hard. I suspect it clipped and did the damage. Make sense to you all? or is there something else I should check before swallowing hard on a replacement part?

[madmac]

I will say something here and it may or may not be founded. Bi-amping speakers creeps me out!. It's not like there is anything inherently wrong with it, it's just that I find in most cases, that it is not necessary. Tweeters are especially susceptible to damage from excessive power. It takes only seconds to blow a tweeter!.

[Greg Gale]

add me to the sad folks with busted diamond tweeter. At least I think so. Was playing my 800D rather loud yesterday as I was on the first floor and wanted to enjoy the music from upstairs. Mine is not shattered but does have a slight discoloration on the dome, almost like a faint shadow of a half inch long or so, and it is dead quiet. Switched L to R the speaker cables at the amp and no change, so it must be something in the speaker. MR and woofers are fine. I am driving the 800D with a 200w Rotel amp and the volume was at "11 o'clock" on choir music....so it was being driven hard but didn't think it was that hard. I suspect it clipped and did the damage. Make sense to you all? or is there something else I should check before swallowing hard on a replacement part?

200W for the 800D is not really giving you a lot of headroom to play music loudly. Having the volume control at 11 o'clock has very little relevance to the output of the amplifier. This can vary dramatically depending on the output of your source and the recording itself. The 800 and 802 series is known for being very demanding on power requirements especially since the lower frequency range they dip down to below 3 ohms which can put an extreme burden on your amplifier.

Tweeters are more susceptible than other drivers to clipping which may have blown the tweeter.

[toddmorr61]

well, did some diagnosis and yes it is blown. Resistance across the terminals of the bad tweeter is 0 ohms. Resistance across the good tweeter is about 3 ohms, which is more or less in spec according to dealer. So the lesson is learned...don't drive power hungry speakers loudly with a 200w amp.