Why do we need crown?

[A440A at aol.com]

Ron writes:

<< And I was, of course, talking about something designed and 

built for zero bearing and zero crown throughout, not 

something that was designed for positive bearing and crown and 

badly built. >>

  Greetings, 
     My parents' piano is a 1870 Hallet & Davis. It is not veneered, but 
rather made with solid maple body parts.  The soundboard is completely flat,and 
was designed that way. The bridge has agraffes that have steeply slanted holes 
in them, and they alternate so that the back strings are either rising from 
them to meet the hitch pins, or slanting just as steeply down to the hitch.  The 
effect of the alternating bearing is to rigidly lock the board in place.  This 
piano has a boomy bass and a weak treble.  
     I tried all sorts of things, but there was no way to get an even 
response out of this board.  I have some rather serious misgivings about flat 
soundboards.  
Regards, 
 
Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html