Diamond drivers

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 Young’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 materials’ 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.

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.

Thanks
Bill

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.