Eoin wrote:I'd need to check the maths but I think the time taken for it to decay to a proportion of it's peak will be the same regardless of a high initial peak or a lower one. I havent got a reference but perhaps I'll have a look. You should find that the time for any pulse tondecay to half of it's value (or any proportion) will be the same.
Yes, that's correct maths, Eoin.
However......back to the cymbal analogy, plainly different things happen according to how hard a cymbal is struck. Again, its a difference between simple models and what really goes on that is interesting. Many and various vibration modes have different decay rates, spectra, and damping. All wrapped up into the same cymbal. One material. Behaviour determined by structure.
I also hate damping good cymbals, BTW. But as an illustrative point, one can alter tone and shape specific resonances without affecting overall decay time, with application of certain type of damping. Generally for the worse, I agree, JL. Same could well be true of good platters. It's not a bad analogy, perhaps.
catsquirrel wrote:And the frequency dependency thing is well known, as is the temperature relationship. I have measured both.
No, the way you are measuring material damping factor is flawed, catsquirrel, and hence significantly frequency dependant. Standard material property definitions are not frequency dependant, intentionally so. And of course certain material properties change with temperature, sometimes significantly. It's not that damping does not play a part in what you are measuring, it's just not a defining or unique part, and other factors equally apply.