Diamond drivers

Out of curiosity I was wondering why diamond speaker units seem to be on the rise. Brands like Marten Design and B&W and many more are selling speakers with diamon tweeters. So what does make a diamond tweeter so good? Or is it just marketing hype. Although I doubt Janzen en Accuton are just making diamond tweeters for marketing reasons.

Yesterday evening I spend two and a half hours listening to the new Raidho D-1 speakers, they use a ribbon tweeter and a diamond mid/bass unit. I have to say this is the best monitor speaker I have ever heard. It is also a 17.000euro monitor speaker so for that price it better be very good.
They are not marketing hype in the sense they have genuinely lower distortion. They probably are in the sense of making an audible difference commensurate with the cost.

A speaker maker I know (and he is not the only one) says the order of priority in what makes a speaker sound good is enclose resonance, crossover quality, then drivers. Most of the time enclosure resonance swamps any advantages in drivers. The best speaker I have ever heard uses the $75.00 HDS tweeter while my speaker uses a $500.00 Morel Supreme. It's a better tweeter and you can hear a slight difference - its a bit darker than the HDS - but the other speaker is way ahead because its lined internally with 1/4 inch copper plate, has 1 inch iron bracing and heaps of copper angle bracing giving it 1/20th the resonance of my speakers which are already lined with steel. It also uses Duelund Cast capacitors instead of VSF Copper. It is way more dynamic and articulate than my speaker.

Well diamond is very stiff and can be super thin, and stiff and light is perfect for a diaphram.
So yeah it is real sscience.
And still it can be turned into marketing hype.
I have a pair of Sony earbuds with diamond diaphrams from when the tech first came out. Still use them with my laptop.
Steve Mowry says in the article "The Whole Truth About Beryllium Diaphragms: -

"For a given geometry the first bending (break-up) frequency is proportional to the material Speed Of Sound, where the speed of sound within a material is defined as the square root of the YoungÂ’s Modulus divided by the Mass Density, (m/s); the higher the better. However, the Mass of the diaphragm must also be considered. Then the ratio of the Speed Of Sound to the Mass Density can be used as the materialsÂ’ acoustic figure of merit, (m4/kg/s); the higher the better."

After that he shows values of "Acoustic Figure of Merit" for different material (higher the better)in m4/kg/s

Berillum - 6.97
Diamond - 4.92
Aluminum - 1.86
Titanium - 1.13
Steel - 0.63
I can give you an example. The 800 diamond series compared to the Monitor Audio Platinum series. The Monitor Audio with there ribbon tweeter let you hear more information than the diamond tweeter of B&W. It makes depth even more easy to get. At the end it is about the quality and resolution you can hear! There is a big difference in filters they use and make.
Mordante, I only have experience with Accuton ceramic and diamond tweeters, so i'll comment from that experience. Firstly, the Accuton Diamond tweeter in its various versions is a significant improvement in clarity over the Ceramic tweeter. Likely the biggest distinction will be that the diamond diaphragm will not be subject to over heating as the diamond lens will dissipate heat very efficiently. Granted this is not a big issue but listener fatigue is less with the diamond tweeter, and this 'fatigue', perhaps too strong a word, will be only apparent over very long listening sessions.

The great part about the diamond tweeter is that you cannot hear it. Obviously one hears the music, but without any driver signature at all. These nuances are easier to hear if you have a lot of experience listening to different tweeters. There is a speed and ease which is hard to quantify but easy to hear as the music only. I mentioned the concept of fatigue before. With conventional drivers, this is a phenomenon which manifests itself with tweeter information becoming hard or glaring as the driver heats up with long continued use. The diamond tweeter will never have this issue as it has a very efficient dissipation of heat inherent in the material.

Hi Mordante , where did you listen the Raidho D1 speakers? I too have spent 2-3 hours with them last friday (in Amsterdam at A10 audio).

Bo1972 make two very good points:

1) How the tweeter is made is very important (probably as important as the material), e.g. to me the Focal beryllium tweeters always sounded better than the B&W diamond ones.

2) There are ribbon tweeters (quite a few in fact) that are at least as good as the best dome ones. The Raidho ribbon tweeters are among the best tweeters available at the moment, and chances are that no dome tweeter can touch them.

I also heard those speakers ate a10 audio in Amsterdam.
I heard all the Raidho speakers at CES 2013 and was not impressed. It is a favorite of Valen's which means hifi sounding and it sure is.
I had an off the record with a B&W wholesaler about 2 months ago Re:diamond tweeters. This person was of the opinion that its a marketing ploy and they cant really achieve anything more than a standard tweeter.

This is not intended to cause an argument. Thes chap is as close to the horses mouth as I can get anf thats what he said.

I still said I want a diamond tweeter replacement. He said sit down im about to give you the price.
Jwm, don't you think making a sweeping statement after hearing a pair of speakers under show condition is premature, if not unfair to our fellow readers? I have heard the Raidho C1.1s (with proprietary ceramic mid/bass instead of diamond, same tweeter) at length, and I have compared them to best out there in terms of naturalness in reproduction (eg, Quad ESL 57s, Sound Labs, Magnepans, Harbeths, Verity, Apogee, etc). The Raidho's IMO competes with the best out there, regardless of cost. I think we agree that Valen's choice of speakers in the past have been on the wrong side of natural (eg, Magico), but I think he he's spot on about the Raidho's. I can't wait to hear the D1s.

Raihdo is one of the very few company's that design their drivers in house from ground up, which gives them so much more control of the sound of their drivers than most other companies. Their planar magnetic tweeter is one of the best I've heard and is not fatiguing. And I've heard the best out there including AMT, plasma, ribbon, electrostatic, diamond, and beryllium tweeters. I think the new diamond mid/bass driver is ground breaking. No one else has done what Raidho has with diamond. But I will hold off on judgement of the sound until I hear the D1.

As for the crossover in the Raidho, I discussed the choice of crossover parts with the designer at RMAF last year. He's thinking is different than most designers when it comes to crossover component choices. He has tried the Duelund cap, but he said it made his speakers sound "slow". He prefers tin foil film caps rated at low voltage just enough to do to do the job, because this results in faster truer response according to him. He likes tin over copper because it can be manufactured with closer tolerance than copper. I think the caps in Raidho speakers have tolerance less than 0.5 %. Not sure about the resistor type used in their speaker. Wiring is by Nordhost, not a big fan of this wire, but I can't complain.

I looked at the construction of the C1.1 cabinet carefully. The slanted mid/bass baffle reduces floor bounce and integrates better with the tweeter. The thick aluminum baffle is stiff and nonresonant. But the HDF cabinet is resonant compared to Magico or Wilson and is designed to dissipate resonant energy through the specially made speaker stand, in contrast to the brute mass loaded speakers of most high end manufacturers. It's pretty impressive how much vibrations are dissipated through the stand. I think it's clever engineering and seems to work well.

The price of the D1 has given me pause, but I think it is still less than the Magico 2 way monitor.
Design is the 1st order of priority. For if design is wanting the best cab network drivers are not going to improve it much.
Johnk, not sure what you're driving at. The crossover, driver, and cab work are all part of the essential the design work, although some may argue that the crossover is the most important.
Dracule1 no I report it as I hear it. Sure home editions could change the outcome, but I heard enough of them in enough rooms with different equipment to base my own conclusions. I have been at enough shows to get a basic flavor for things. It is how I hear it and I am not discouraging anyone from listening on their own. They are not my cup of tea.
Okay. I've heard them at shows myself and haven't been impressed either. But get them in a proper audio room, and the sound can be transformative.
Diamond tweeters are for real. While they do make for good marketing and unfortunate price increases, they deliver.
I have owned the following loudspeakers over the last ten years: B&W CDM1, CDM2SE, CDM1NT (Aluminium tweeters), Jamo Concert 8 and 11 (Silk dome tweeters), 804S (Aluminium tweeter), 803D and 803Diamond (Diamond tweeters).
As context for my observations: I am very sensitive to any tweeter harshness.
I like the silk dome tweeters, but not so much Aluminium dome tweeters - they tend to have a residual metallic sound. The better Aluminium versions will only occasionally highlight a distortion artefact, as opposed the less accomplished versions which are almost unbearable after a few minutes.
However the diamond tweeters are clearly superior: better transient response, cleaner, more precise sound-staging, transparent to quality of recording and audio equipment, consistent sound quality across their frequency span. And yet they are easy on the ears - I can listen for hours without fatigue to the 803D and 803Diamond loudspeakers.
I have heard many other loudspeakers at dealers with different tweeter technologies including Beryllium and Ribbon. I haven't heard anything at dealer that would indicate an obvious weakness with the B&W Diamond tweeters. However, as always, a definitive comparison will require extended home auditions.
You are right about the pleasant sound of the Diamond tweeters. But there is more than only the tweeters. The biggest problem B&W has is that they still not make great filters. Wenn you do a test for depth and how wide the stage is, B&W is quite poor. This was the main reasson why I did not want to continue with B&W. I owned the 802N and 800S. The new series still have this problem. Depth ann a wide stage are one of the most excitings parts of highend audio. Wenn this is not that exeptional good, you miss a lot of excitement during listening to your favorite music.
I think the new diamond mid/bass driver is ground breaking. No one else has done what Raidho has with diamond. But I will hold off on judgement of the sound until I hear the D1.

Ground breaking indeed and a complete sonic treat. I have the Raidho D-Series under audition at home at the moment and I maintaining a blog that can be found HERE. Raidho is the only company of Know of that builds its own diamond coated bass woofers.

Very interesting and much appreciated! As I'm seriously considering the Raidho D-2 or D-3, I will read and follow the development of your thread carefully.
Off topic, perhaps, but in respons to poster Jwm:

I heard all the Raidho speakers at CES 2013 and was not impressed. It is a favorite of Valen's which means hifi sounding and it sure is.

I once owned the Raidho C1.0's(w/upgraded Raidho binding posts), and while my main issues with their sonics may not address your "quibble" on Raidho speakers sounding "hifi," based on your recent CES impressions, I'm guessing my own impressions carry strong remnants of "hifi"-sound that applies to your usage of the term.

I could start out by asking what you mean with speakers sounding like hifi, but what rubbed me the wrong way with the C1.0's was a noticable lack of energy or "aliveness" in central areas. I would describe them as extremely elegant sounding, unfluttered, well-balanced, highly resolved, and quite composed - though on the verge of (or rather trespassing the line of) being a bit dull-sounding. By 'dull' I mean a certain lack of dynamic expressiveness as well as the lack of ability to make me "feel" the fabric and palpable quality of the music, as if being robbed the unwarnished rawness of the sonic material at hand. Moreover Raidho speakers in general have struck me as having perhaps a tendency to emphasize spatial information that makes it feel slightly unnatural at times.

Within the realm of the more or less "typical" hifi-speakers above named issues may not be that prevalent, and there are certainly qualities found in the Raidho speakers' sonics that makes them the preferable choice in many cases here, but my latest(i.e.: last two years) endeavors with compression driver-fitted waveguides and pro-style paper-coned 12" woofers have made a huge difference in addressing my complaints aimed at the Raidho's(and hifi-speakers in general), radically tilting the sound away from the (to my ears) too smooth and "dull" imprinting. Now to be found is instead a dynamic explosiveness, "ignition" at lower levels, the sense of real instruments and voices being played, scale in spades, and not least the overriding feeling of effortlessness - very, very important, to me at least, in setting the music free and making it sound real. I gather these traits go somewhat contrary to what is usually seeked and cultivated in the hifi-domain in general.

Put shortly the Raidho's became too cultivated, too spacious, and too dull and smoothed out to my taste, and my main reference in coming to realize this was the frequent attendance of live, acoustic concerts - in tandem with a gut feeling. Hifi has veered off too strongly to become cultivated and tamed, and while Raidho has made efforts to avoid exactly that I believe their course has yet to address it properly. Somehow I doubt expensive diamond cones will make any significant changes to this signature, and that the tendency is instead linked to the overall implementation of the product.

Just my 5 cents...
Phusis, the C1.1 are suppose to be significantly more dynamic and more emotionally connecting to the music than the C1. So may have gotten what you're looking for in the C1.1 that C1 was lacking. Roy Gregory have compared both side by side, and that was his conclusion.

Phusis, I understand about dull speakers, which speakers do you think are NOT dull?
Seadogs1 --

Phusis, I understand about dull speakers, which speakers do you think are NOT dull?

As in "NOT dull" = real life vitality? None, presumably, and yet; fortunately what mimics real life sonic conditions do not require for an absolute replica, but works within thresholds where approximations of a certain order make for startling realism. It's just that many if not most typical hifi-speakers linger on the wrong side of the threshold that translates into "NOT dull," as I hear it. My own speakers, and their sibling models, are certainly not dull, as aren't many other alternatives fitted with compression drivers or (to a lesser extent) even tweeter domes in front of larger waveguides/horns - like all models I've heard from S.P. Tech/Aether Audio, various DIY solutions, JBL K2's and Everest, and others.

It's not only a matter of most notable compression drivers used in front of waveguides, typically used from 800Hz to 1kHz and upwards to 18-20kHz with 1" exits, but also very important is the bass/mid driver where such are not low fs units as typically seen in smaller 2-way hifi-speakers, where even 6 1/2" mid/woofers can get relatively sluggish in their upper working areas. A 12" mid/bass unit with a lighter paper cone and strong motor can make small wonders in the lower to central mids, I tell you, leaving smaller hifi-units pale in comparison, and moreover makes for a more ideal energy coherence transition in conjunction with a 12" waveguide than what you'd see between a 6" unit and a 1" dome tweeter or even a ribbon-like unit used in the Raidho's.
Dracule1 --

Phusis, the C1.1 are suppose to be significantly more dynamic and more emotionally connecting to the music than the C1. So may have gotten what you're looking for in the C1.1 that C1 was lacking. Roy Gregory have compared both side by side, and that was his conclusion.

Thanks for the recommendation and link(have read Mr. Gregory's review already, but still..). I've been wanting to hear the C1.1's for some time now, but haven't got around to it yet; I don't regard myself as a serious, potential C1.1 buyer, and therefore have left it for the chance to show itself for a more "informal" listening session. Gregory's review is promising though, but I suspect, at least judged by his initial and very favorable review of the C1.0's, that his inclination towards the hifi-ish sound would leave out trademarks in the overall sonic nature of the C1.1's too severe for me to overlook. We'll see, but I'm sceptical...
Phusis, may be you should skip the C1.1 and have a listen to the new Raidho D1 with the diamond mid/bass driver. Dynamics are supposed to be significantly increased over the C1.1.