Kuzma 4Point Tri-Planar

Relax Ralph, I was alluding to the author of the comments you were quoting.

Not you.

You guys are going to have to do better than "they make musical instruments out of wood". Well, yes. And they DON'T make bells out of wood, for very obvious reasons. Any body can show this. What is going to hold a standing wave longer? Wood or metal? And let's stay within the materials used to actually make something resembling a tonearm.

All of those curved arms, damping material added to metal tubes, damping troughs and fluids. Why was all of this developed? Because of standing waves in metal parts.

Yes, and at the same time a set of wood blocks can be quite loud, as can even a set of drum sticks. And they make instruments out of metal too- a dobro is a good example.

The point is that wood is not **inherently** non-resonant. If its going to have non-resonant properties, it will have to be treated, just like metal has to be treated. Anyone who tells you otherwise is pulling your leg.

I would think a further issue of wood has to do with dimensional stability, especially with respect to humidity. I know you can seal wood to a certain degree, but IME humidity will still seems to find ways to affect it. Anyone who plays an instrument or dealt with a sticky door has experienced that.

Although most metals would seem to have greater resonant properties, the big reason they get used in an application like this is that the properties are quantifiable. If you know at what frequency a particular structure will become resonant, it can be a fairly simple matter of damping it effectively by other means. We do this all the time with our preamp chassis- the front panel resonates at one frequency, the chassis at another, tightly coupled the two rob energy from each other and will not resonate. Empire did this with the platters of their 498, 598 and 698 models.

Wood is less quantifiable. Instrument makers are well-known for using a small hammer to strike a wood sample to see how it sounds. Same species, same forest, same glade, same tree and several cuts can all behave differently. I've built a number of flutes and experienced that as well

Ralph,

Thank you for offering a sublime example to buttress my argument (viz., musical instruments made of wood). Instrument makers use wood precisely because the phenomena I described occur differently depending on the particular wood. This allows them to control the sound of the instrument. It's the reason we have spruce sounding boards but ebony or cocobolo fingerboards and bridges (and tonearm wands).

The following are demonstrable and proven for any kinetic energy travelling through any material:

- the energy will reflect and/or diffract at a material boundary.

- the velocity of the energy will vary with the density of the material.

- the energy will be reduced in amplitude, slew rate and/or frequency in proportion to the flexing of the material in response to the energy, if any.

Perhaps you've not considered that these phenomena occur at the microscopic/cellular level inside an acoustically excited piece of wood. The laws of physics apply inside the wood as much as outside. We just need to think INSIDE the box. ;)

Saying that wood (woods, actually) is less quantifiable or more difficult to work with is quite different from dismissing the phenomena I described, which you acknowledge exist based on your own examples.

The phenomena exist as I described them, personal remarks notwithstanding.