Porritt, David wrote: > David: > > I'm going to make a little change this summer on a piano > and I'm very much a beginning student in this area. I > understand most of the factors you're talking about but I'm > not sure what difference I am going to hear with a change > of Z. 'splain please! > > dave Loudness, or perceived volume, power, etc, etc. Like inharmonicity, it's more a comparative value than an absolute, and is most valuable at scale breaks. The thing with scaling formulae, is that they are reference guidelines, like road maps. Not only don't they take soundboard response (which is a factor) into account, they aren't a high accuracy representation of much of anything else either (also like road maps). Tension is the most dependable of the calculations, but since it's calculated from theoretical Hz rather than Hz fitting inharmonicity into the tuning, it's inaccurate as well. Steve Fairchild developed an iterative spreadsheet years back that, using scaling formulas and string measurements, adjusted Hz to accommodate inharmonicity, and recalculated the formulas until it stabilized. In other words, it calculated the tuning from the physical dimensions of the strings. Pretty cool. This would produce more accurate scaling results, but it's a few decimal places beyond what we can hear for scaling purposes, so it's probably not really worth pursuing for that. I'd love to get a copy of it to play with though, for my own amazement. For string scaling, what we have is quite adequate, in practical terms of what we hear compared to what it shows us, though a rational approach to faking in soundboard response for the Z would be nice. So like everything else, it depends... sort of. Lots of judgment calls go with the numbers. Ron N
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