Diamond Tweeter Modding

[RebelMan]

I had this really far out idea to modify my B&W 803S speakers (that’s right the 803S) with diamond tweeters. I didn’t see any technical issues that would hinder such a change. After all, the 803S is virtually identical to the 803D, with the exception of the tweeter and the additional bass driver. So, I contacted my dealer to see if they would be willing to purchase and install the new tweeter.

They tell me that B&W will only exchange diamond tweeters and that they will not sell them. Hmm, all the more reason why I think the operation would be doable. Perhaps the future Signature replacements (if there is such a thing) are going to include the diamonds and B&W doesn’t want to impact their sales with people modding their 800S series speakers.

Am I the only one or has anyone else thought about modding their 803Ss (804Ss, 805Ss) speakers with diamonds? Anyone run into the same or similar road blocks? :roll:

[tboooe]

Fascinating idea. I would worry about the total integration of the components. I dont know for sure, but I assume that B&W tuned each speaker series to work well for that particular combination of tweeter, mid, etc. Exchanging just a single component may upset this balance and be a case where the sum of the parts is more important than the quality of each individual part.

Aside from that, I just dont have the stomach for taking apart my speakers (though I dont actaully have speakers right now). I have no problem tearing apart my motorcyles and having extra parts after I put them back together, but speakers???? too scared....

[RobP]

I have thought of the same idea but never asked. Even though I own the older line (N803's) I would have thought that there would have been mods available for those on the upper end. I guess B&W just wants people to buy up and purchase the new 800 Series. They will make more money this way.

[Sim reality]

I dont know for sure, but I assume that B&W tuned each speaker series to work well for that particular combination of tweeter, mid, etc. Exchanging just a single component may upset this balance and be a case where the sum of the parts is more important than the quality of each individual part.

I'm just a poor newbie at this point, so i don't have the 800s, but I think the biggest difficulty is getting to crossover to match because "The older models used a flat cellular material, where the new tweeter has a synthetic rubber half roll surround. This in turn has improved the tweeters' low frequency behavior" which means they probably re-tuned the crossover to take advantage of this.

That said you could probably do it, you just need a really good friend with the 803Ds so you can disassemble it to look at what inductors/capacitors they are using on the crossovers... Then the next hurdle would be to find the actual diamond tweeters and inductors/capacitors...

Anyone close enought to the B&W plant to do some dumpster diving? :B

[Pieter]

When was the last time you chaps were at the B&W site?

Get there! Under the top pop down menu select "Products" -> "Product ranges" -> "800 Series".

You'll see, if you scroll to the bottom, that a new product has been added, "Kits".

Under "Kits" you'll find all the seperate components needed to build any of the 800 series speakers, or any hybrid thereof which should take your fancy.

There's even a sub-section, "Tips", that has all the techical know-how garnered at B&W since its early foundation, condensed for easy assimilation into pithy one-liners like, "The bigger the box, the better the bass." or "The best cross-over, is no cross-over."

Reckon you can't go wrong...

But be quick, before B&W changes its mind and removes the new products from their site listing.

[RebelMan]

Pieter, it does not appear to be listed under the "United States of America" country site. Can you provide the URL?

[RobP]

Pieter, I cant get it to come up either, please tell, dont be a tease. :rf

[jlr_1304]

If you take a look in my thread, http://www.htguide.com/forum/showthread.php4?t=15784, i've asked the same question, but for the 802.

Seems like it's not easy, but surely doable.

[RobP]

Hey jlr, If you are talking about just replacing your defective tweeter with the same model then it is really easy, it just takes a gentle touch, but replacing it with another model may take a little more work.

[Aussie Geoff]

Pieter,

You are "trying it on" in that a full Google seach of the BW site reveals only 2 uses of the word kits and they are to do with speaker mounting kits for wall mounted sites....

Geoff

[Aussie Geoff]

Everyone Else,

Re the tweetrs, "Sim Reality" is right - the crossover is very diferrent in the new speakers - just a single capacitor for the tweeter to roll off low frequencies, with a more complex arrangement for the mid. Also the tweeter and mid are now in phase, where they were out of phase before...

I think only the most advance DIY speaker designer should even consider this kind of mod...

Also - B&W generally only has a policy of selling spares for the 800 series to 800 series owners - so I think people would struggle with the parts...

Geoff

[RebelMan]

Joke's on us people! It just occured to me that "link" does not exist and never did. Pieter was just being a typical smarta$$. :evil:

[RebelMan]

Everyone Else,

Re the tweetrs, "Sim Reality" is right - the crossover is very diferrent in the new speakers - just a single capacitor for the tweeter to roll off low frequencies, with a more complex arrangement for the mid. Also the tweeter and mid are now in phase, where they were out of phase before...

I think only the most advance DIY speaker designer should even consider this kind of mod...

Also - B&W generally only has a policy of selling spares for the 800 series to 800 series owners - so I think people would struggle with the parts...

Geoff

Sim is correct with regard to the older series only but not when it comes to the newer series. It would be considered a dealer installable modification because of the FST midrange tuning that would be involved after it's removal, too advanced for the mechanical neophyte.

Geoff, so do you think a dealer could/would do it?

[RebelMan]

If you take a look in my thread, http://www.htguide.com/forum/showthread.php4?t=15784, i've asked the same question, but for the 802.

Seems like it's not easy, but surely doable.

Thanks for the heads up jlr, but I think that thread started in a different direction. I am not looking for a fix to an existing tweeter, but an upgrade to a better one. Chances are it's not possible but I wanted to see if anyone else has looked into the possiblities or even tried it.

[RobP]

Joke's on us people! It just occured to me that "link" does not exist and never did. Pieter was just being a typical smarta$$. :evil:

:smackbutt:
DAMN!!!

[jlr_1304]

Thanks for the heads up jlr, but I think that thread started in a different direction. I am not looking for a fix to an existing tweeter, but an upgrade to a better one. Chances are it's not possible but I wanted to see if anyone else has looked into the possiblities or even tried it.

If you look further down, someone said that the new cone wouldn't fit on a non "D" model tweeter.

But the first culprit would be to get the tweeter from B&W.

[Pieter]

Joke's on us people! It just occured to me that "link" does not exist and never did. Pieter was just being a typical smarta$$. :evil:

Sorry, I just could not resist and had to give in to my weak side.

[RebelMan]

If you look further down, someone said that the new cone wouldn't fit on a non "D" model tweeter.

But the first culprit would be to get the tweeter from B&W.

I trust the source that this is true with regard to the older 800 series. The same cannot be said of the new series nor was it implied in your reference. In fact the diamond and aluminum tweeters share the same surround on the new series. From a technical aspect I believe it is possible but maybe not from a practical one. One would the need the cooperation of B&W and a dealer willing to participate in making the change. It was just a thought.

[Rolex]

There has been talk of the crossover not being the same. But, I think we are forgetting that he asked about modding the 803S. Which is, of course, the new model with the new crossover in it. Granted, I'll bet the D crossover is slightly different than the non D crossover, but it would be a whole lot closer than the nautilus crossover.

[PewterTA]

Has anyone even thought about the time smearing of the Diamond tweeter in relation to the FST driver? That's why they moved the tweeter more forward. Along with the crossover you would have to adjust to a new positioning of the diamond tweeter. All in all, you're better to just buy the 803D speakers and not have to try to "calibrate" it all yourself.

[RebelMan]

Rolex: That is the millon dollar question. Is the D crossover identical to the S crossover? I suspect that it is.

TA: Both D and S tweeters have been realigned (push forward) to make good of new 1st order crossover AND tweeter surround. Perhaps one is better off going with the 803D, provided they have the space to accomodate it (and the matching center). :W

[Sim reality]

As fun as this thread is... I just realised it's rather academic:

1) you need a friend with a 803D that could order spare parts for you
2) You need to be brave enought to tear apart $6-8000 worth of speakers to get the tweeter in (and maybe crossovers but I think RebelMan is right... The only other place they could have gotten the crossovers at a decend cost would be the outgoing signature series)
3) Even if they are bolt on (as in you bought the entire tweeter module) when you try and put it back together you don't have the proper torque specs to reassemble the speaker properly (I am pretty sure that how tight to bolt something down will affect the sound more then the incremetal change from Aluminum to Diamond)

Definitely not something you want to try unless you have one of those service manuals so you know how to "tune" the speaker...

[DrJRapp]

After all, the 803S is virtually identical to the 803D, with the exception of the tweeter and the additional bass driver.

I think there are a lot more differences than that James. I've done a lot of listening to 803s, 803d and 802ds recently, and the sonic difference on the top end between all three isn't really audible except in direct a/b. It's more a distortion issue at VHFs, than anything directly audible. The additional woofer, more sophisticated cross-over and cabinet size in the 803d does make a huge difference, however.

I also believe that if you did such a mod you would probably wreck the used market value of your speakers.

I recommend you just sell them off and get some RF7s if you want a hotter top end! ...or bottom end for that matter... (just kidding).

[RebelMan]

Jerry, I have made similar comparisons between the 803Ss and 802Ds and to a lesser degree the 803Ds and the differences in treble has been quite noticeable to me. Even without the need for side-by-side comparisons. Case in point, even my wife seems to think I have canine hearing. 8O

The diamond tweeter was designed to push the high frequency distortion levels beyond human perception and I have clearly noticed this. I believe that the big differences you are referring to are acoustical observations but not technical observations. While the 803D does sound more dynamic overall than the 803S does, my aim was simply to smooth out the top end of the somewhat edgier 803S and technically speaking I believe this could be done.

Maybe when my hearing has suffered the trauma your's has I will hear little or no difference either. LOL :lol: (just kidding too!)

P.S. Do you know for sure that the 803D crossover is different from the 803S (not the N803 which I know is different)? I was under the impression that they were identical.

[DrJRapp]

I didn't get the impression that either the 803s or the 804s were edgy relative to the 802d and 803d. Perhaps you are perceiving the fact that the former two have significantly less bass than the later two, so, in anything more than a small room they would sound more treble heavy (edgier) at the same overall spl.

I think you just need more speaker overall to satisfy your room (and ear)requirements .

[RebelMan]

Perhaps you are perceiving the fact that the former two have significantly less bass than the later two, so, in anything more than a small room they would sound more treble heavy (edgier) at the same overall spl.

The demo tracks I played were laced with cymbals and I could easily distingush the more natural sound reproduction eminating from the diamond tweeters. You probably think I am making this up but it was so apparent to me. If you have been following B&W's R&D you would have known that they considered utilizing TWO tweeters in the new 800 series. In the end they decided against it because it didn't provide the benefit they were looking for. Similar conclusions can be drawn from their decision to use different materials between tweeter assemblies. Only this time it gave them the results they were pursuing. My ears seem to agree with their findings.

I don't doubt the fuller bottom end of the larger models would fill an otherwise large room better but regardless of venue they wouldn't mask (color) the highs. That's what Klipsch is for. LOL :lol:

[DrJRapp]

B&W had to resort to synthetic diamond material to make it's domes as rigid (and as distortion free) as Klipsch titanium domes. Unfortunatly, that diamond material is also heavy, resulting in slow response. That is what gives the 'D" series it's laid back sound on the top end, and required B&W to move them forward to adjust the time line.

[Aussie Geoff]

Jerry,

I am going to presume you have posted with your "tongue in your cheek" with those comments... (Like several others in this thread)

However, for the benefit of others...

For example the reason the tweeters are moved forward in ALL the new 800 series range, not just the diamonds is is that the new simpler crossover uses a single capacitor for a 1st order cutover for the tweeter leaving the signal in phase with the midrange at the crossover point... Previously the more complex higher order crossover had put the treble out of phase with the midrange at the crossover, requring the tweeter to be stepped back a 1/2 wavelength to compensate....

And I won't even bother with your heavier cone comment.... Suffice to say that the aluminium tweeters in B&Ws Nautlus range have always had a resonance above 20 Kz which can give a real peak (6-10db) in the 28-30 Kz range (vaires on the tweeter mode). This can make them sound edgy even when people can't hear the very high frequency sound... The new S series tweeters are better but still have that ultrasonic ring... The diamond tweeters resonance with way higher and filtered out giving the D tweeters very low distrotion a smooth gradual roll off from 20 Kz to 50 Kz+...

Enjoy your new B&W's Jerry - they just may convert you from the Klipsch dark side... I know you are tempted...

Geoff

[Blazar]

Are you SURE the diamond is heavier than the titanium? The diamond may be more dense but their process may have allowed them to make them very thin to compenate...

I'm not sure how accurate your statement is until I see some actual weights of these things.

Back to the topic of this thread... I would be skeptical about putting diamonds into S series since the crossover network would be the same. My understanding is that the crossovers are calibrated to the final speaker and not the other way around. If the crossovers can't also be properly modified for frequency response, I would wonder what would happen to the sound.

[Sim reality]

I thought B&W was more concerned with the beryllium that came out of Focal/JMLabs then the titatium ones (which have been out for a while).

Titanium is stronger then aluminum but more flexible and better damping so the trade offs depend on Manufacturing... Beryllium is stiffer and stronger then aluminum and therefore has more extended high frequecy response.

Diamond is stiffer then Beryllium but more dense and Beryllium has better damping which onces again comes down to manufacturing.

I have been scanning the articles and is seems to indecate that all the 800s crossovers are new and the specs indecate that the crossover occurs at the same frequencies... Given that if the crossover is at the same frequencies it nominally uses the same capacitance/inductance (especially on a 1st order crossover) the only thing you would be able to tune is the crossover slope based on capacitor/inductor type.

Now according to the 800 series developement paper even the engineers weren't sure why one electronic component sounded better then another... So given that they could not "engineer" that in and seeing that B&W only seems to build in "features" they could understand (after all, I couldn't beleive Nautilus crossovers were still using iron core inductors!). I am guessing the accountants took over and told them to use the same components so that they could spend the research time on something that would give broader gains for the entire range.

But I guess I am just speculating...

[DrJRapp]

Are you SURE the diamond is heavier than the titanium? The diamond may be more dense but their process may have allowed them to make them very thin to compenate...

I am sure I'm not an MD but a PHD in Mechanical Engineering. Strength of materials is/was one of my strong suits. I spent 26 years in the US Navy and NASA as a test pilot trying to break aluminum, magnesium and titanium structures. The advantage of titanium (at wt 47) is it is a metal matrix that is very strong without being too dense or too brittle and can be fabricated as thin as three molecules and therefore be very light with low inertia. Tweeter domes are structural shapes so an engineer wouldn't worry too much about material flexibility since the shape would compensate. Titanium domes can be fabricated such that the titanium can act as it's own surround. Diamonds on the other hand are crystaline carbon compounds in nature with a much higher molecular weight than titanium, (range is 40 to 167 and that could go higher dependng on how much iron is entrained), anything made from it needs to be thicker to avoid being too brittle. It also requires that another, more flexible material be attached to act as a surround.

Although based on some real science, I suspect the whole diamond thing is more about marketing than speaker performance. After all B& W has already exhausted the reference, signiture and premier marketing buz words and added a few of their own such as matrix and nautilus. They now have cornered the market on gemstones too...LOL

[Sim reality]

Tweeter domes are structural shapes so an engineer wouldn't worry too much about material flexibility since the shape would compensate.

I would disagree... The tweeter dome is a structural shape given a static load and even then the deflection would be detectable within the stucture.

What we are talking about is a dynamic load on the collar at above 20KHz which would cause resonance within the structure in addition we are taking about the frequency that the entire dome would flex enough to not move linearly along the entire raduis of the tweeter.

In that case the stiffness of the tweeter would need to be taken into account because the shallower the stress/strain curve on the material the greater the amount of energy is absorbed into the material and re-emitted sightly out of phase with the initial impulse.

I think if we were comparing material on a side by side basis... For a given area and mass (thickness being a function of density) which stucture would be stiffer because we are not talking about amount of "force to material failure" here and therefore not really talking to strength...

In this respect I think B&W did their homework.

[Sim reality]

Sorry... when I said linearly I was thinking "minimize flex in the dome and move as a single unit"

[DrJRapp]

Domes are structural shapes for both static and dynamic loads. They can be designed such that deflection aproaches a theoretical zero within audible and high supersonic frequencies. We are talking cycles till material fatigue fracture, not force to material failure.

I think we need end this debate because we've lost everbody on the technical points.

[Sim reality]

I still think that in order to design the dome to have near zero deflections for a more flexable material you would end up increasing the mass (probably near the collar)...

But given that proving that quantatively would probably be a good masters project...

Yeah, lets have a truce.

[Kobus]

Well, what you guys point out to us lessors is that a lot goes into the design of these things.

Thanks