I believe I've seen reference to this before.
I'm interested in what a Steinway B sound board assembly might weigh.
Would some of those out there who build bellys be able to provide this info?
Weight of panel with ribs?
Weight of panel with ribs and bridges?
I've never weighed them but I do notice after I'm done some feel heavier than others
I'd like to start keeping track
Thank you list
Fenton Murray, RPT
Well, yes but if downbearing increases sustain it does so by raising the impedance. Impedance just means the rate of energy transfer. Downbearing compresses the soundboard spring, the assembly gets stiffer, the impedance increases and sustain increases.
The purpose of designing ribscales and factoring in downbearing as a measure of the string load is ultimately to control impedance even though we use things like beam formulas, MOI, spring rates and various other checks and balances, including downbearing settings, as the calculus. Mass obviously plays a role as well but the general principle is light, but not too light, stiff but not too stiff. The assembly must both be reactive and controlled.
Finding that balance that translates into something we like probably explains the range of designs that we encounter. I don't know if there's any formula that translates directly to some aesthetic model simply because we can't quantify taste. We recognize when something doesn't work but it's harder to pinpoint a specific tonal outcome from some set of numbers. The reality is that at some point (as Del Fandrich is fond of saying) you have to shoot the designer and build it. You take what you find and build another one tweaking this or that and hope that all other things remain constant. It's a constant process of moving toward some ideal. There are no shortcuts.