Loudspeaker cabinet materials

[ack]

I came across the following chart on cabinet materials - carbon fiber vs all others (CFRP = Carbon Fibre Reinforced Plastic) - on Wilson Benesch's web site, by following the Magico Q7 thread on computeraudiophile.com



Some interesting claims:

It is possible to see that the performance of most metals, including titanium and steel, falls between a glass fibre structure and a carbon fibre structure. It should also be noted that the Phenolics that are used by some manufacturers under the guise of exotic names falls considerably below both. These basic and quite fundamental physical laws, explain why we see carbon fibre structures in F1 racing cars, advanced passenger aircraft, BMW high performance car design, and in fact almost every other application, where performance is a key goal of the design.

Replacing MDF with aluminium is only a marginal benefit, one that is largely offset by zero self damping and problems of self resonance. Even elaborate and complex bracing will only shift the resonance marginally higher, whilst robbing the internal volume of air.

ALL CABINET STRUCTURES RESONATE & EMIT SOUND.
HIGH MASS = LOW RESONANT FREQUENCY = MORE CABINET NOISE
LOW MASS = HIGH RESONANT FREQUENCY = LESS CABINET NOISE
LOW MASS STRUCTURES ARE EASILY DAMPED
HIGH MASS STRUCTURES ARE DIFFICULT TO DAMP

This is the PDF which makes for very interesting reading: http://wilson-benesch.com/wp-content/uploads/2012/08/cardinal-white-paper-1.pdf

Enjoy

 

[Mosin]

I haven't read the paper yet, but it is an interesting claim, especially in light of the fact that a carbon fiber plate or tube is stronger in one direction than others. Its Achilles Heel is that it is repetitively weak otherwise, much like plywood. To make it strong it seems that it would require some of that elaborate and complex bracing that they speak of.

All that aside, I do remember the deHavilland room at RMAF back in 2009. It featured Wilson-Benesch speakers, and the result was an immensely good sounding room.

 

[MylesBAstor]

I haven't read the paper yet, but it is an interesting claim, especially in light of the fact that a carbon fiber plate or tube is stronger in one direction than others. Its Achilles Heel is that it is repetitively weak otherwise, much like plywood. To make it strong it seems that it would require some of that elaborate and complex bracing that they speak of.

All that aside, I do remember the deHavilland room at RMAF back in 2009. It featured Wilson-Benesch speakers, and the result was an immensely good sounding room.

I had the WB tt, arm and cartridge (I know I reviewed the cartridge but can't remember about the tt and arm--though the arm was the predecessor of those that achieve azimuth and VTF with the same counterweight. Let's say that I hate it now as much as I did back then too!) years back as well as the Black Diamond Racing platform and cones all made from CF. In the end CF has its own sound too. And you're absolutely right about the strength aspect of CF!

 

[Mosin]

Don't misunderstand. I am not anti-CF. I just believe that it is a material that requires a lot of special consideration in order to be worked with in a proper way. I have heard it that I like, but when it is wrong, it seems to be atrocious.