<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body bgcolor="#ffffff" text="#000000"> Hey Danny !  Hows ya doing down there ? Long time no see.  As for your problem piano... I wouldn't accept the thing. If they sold it rebuilt for 15 grand then things should be done right. I've heard several mixed reports from techs about SAP... seems to me that such places need to be kept on their toes.  As for how negative crown affects sound and why... it kind of depends on the causes of negative crown.  A board meant to have a positive spring in and an upwards crown crushed beyond flat and boinged inside out is probably not going to develop along positive lines acoustically me thinks... Cheers RicB <blockquote>Custommer wants me to write an expertise on grandpiano Kawai GS80 2.40 meter ° 1980 bought in a pianoshop in 2005 The piano was renovated at SAP in Poland. The duplex bridges where not installed correctly: they started at the left and end up with one string left without, unisons don’t fit on the same duplex,  anyway this is already a main reason to complain. Some comments on this duplexproblem  related to tuningstability are welcome. The soundboard is negativ crowned. I think: soundboard originlly dried for Japanese market, in renovation at SAP Poland extrmely dried out, restrung with to much downbearing and finally collapsed negativ, any other thoughts about why a soundboards becomes negativ crowned? Custommer payed 15.000 EUR for this instrument, Should he accept the fact of negativ crown? Will the board get even more negativ figures in the future? Any experience how negativ crown influences the sound and why? Be happy to get a lot of comment on this issue, Greetings from Belgium Danny boddin</blockquote> </body> </html>