impedance

[Ron Nossaman]

>Dear Ron,
>
>Actually, I had something a little different in mind. I was thinking of
>designing in a system for fine-tuning impedance on purpose, as the piano
>changed with age. That is, a system which didn't have to be hidden or
>covered up, but was just designed in from the first, like tuning pins. I
>could imagine, for instance, something built into a bridge which would
>enable one to change its height. Double bass players have bridges like
>that, since their instruments change so much with the season. 
>
>Suppose, for instance, since people say those crazy automotive springs
>actually worked sometimes, that a large beam went under the middle of each
>rib, and an adjustable spring were mounted there. Each rib's amount of
>support for the board could be individually tuned, depending on how the
>instrument felt in a particular climate or at a particular age ... okay,
>silly, but I just wondered whether it could be done ...
>
>Susan
>

Hi Susan,

Sure it could. With vertical hitch pins, the factory/tech can both set the
bearing precisely where he/she/they want(s) it in all areas of the piano,
and can still change it later, at any point, if the need is perceived
without having to add the weight, complexity, and less than solid adjustable
bridge. An adjustable soundboard spring system is certainly possible, but it
would not only be more expensive and heavy, there wouldn't be one tech in
fifty who would take the time, or care to learn how it worked and how, and
when, and when NOT, to adjust it, or the bridge or vertical hitch pins for
that matter. Sounds a smidge cynical? That's some of that resisted education
that was finally pounded into me through endless repetition. Personally, I
think a well designed system can be stable and dependable, with a reasonably
long service life, without having to do a lot of after the fact tinkering
with it. I'm a real fan of low maintenance simplicity. The trick seems to be
gathering enough of the right information to fill out the picture with
understandable cause and effect relationships instead of just putting band
aids on the boo-boos. I want to avoid the problems altogether if I can, but
that's just me, and there still a lot of holes in the picture.

Best, 
 Ron