At 12:12 AM 8/14/99 +0200, you wrote: > > >Stephen Birkett wrote: > > >> >> I have my opinions about modal analysis (mentioned here once a >> while back)...that, at best, it can tell you that the soundboard is >> working as you already know that it is supposed to work. As a practical >> tool for design I have my doubts it will ever give anything, primarily >> because it treats the sb unloaded and in isolation from the interactions >> with the rest of the piano. >> > >Hmmm.. In the section of the Wogram article entitled "Influence of string >tension" He seems to be saying that the condition of an uloaded soundboard is >not a problem. He says that the basic impedance curve and sound radiation >curves remain basically the same and that only the lowest resonances are >effected and that the effect is predictable enough to take into consideration. >Is this outdated ?? * I don't know about "outdated", so much as "un quantified". It hasn't really been proven either way, as far as I know, so it may, indeed, be a non-problem. Personally, I think the loading, and any resulting impedance change(s) can be factored in to an adequate degree of accuracy once a rough and relatively simple mathematical model has been constructed and reasonably calibrated against what can be directly measured and heard. I don't see any reason it has to be precise to fourteen decimal places, other than the apparent fact that no one has a model (modal or otherwise) accurate to ANY degree of accuracy yet, but there seems to be a bit more leeway in actual practice. If one wants a digital readout, however, one will require lots of decimal places, even if it's SWAG generated, for the visual effect. If we could get anywhere in the ball park with a mathematical model, I think it could be quite valuable as a preliminary ranging shot in the design process, before you are actually listening to the results and it's already too late. I see it as potentially offering more information to an informed decision... kind of like using an ETD to improve your aural tuning skills. Ya think??? Ron N
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