<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html>   Hi folks. This subject has been up from time to time with varying opinions about its worth, and questions about whether or not factories use it, and why.  I like to try and ask people directly if I can, and I got this back from one of the fellows at the research department at Petrof. Thought you might like to hear what he had to say.     <blockquote>"Dear Richard We are using EMA for piano design. Most of all we are observing modal shapes of soundboard with / without bridge in free conditions. We have also laboratory brass frame for fixed piano soundboard conditions (can be seen in our web bulletin No 01/2000). Ocassionally we make also EMA of grand outer rim. It can be helpfull for construction changes results observing . For instance comparing of modal shape amplitude between soundboard and rim can say something about acoustic efficiency of new prototype. We made some works on computer modelling of piano soundboard by FEM and comparing Fem model modeshape results with real soundboards from EMA. Some results of my colleague work You can see at proceedings of ISMA 1995 France, Dourdan - Alois Raffaj: Vibrations of piano soundboards, pg 373."</blockquote> -- Richard Brekne RPT, N.P.T.F. Bergen, Norway <A HREF="mailto:rbrekne@broadpark.no">mailto:rbrekne@broadpark.no</A> <A HREF="http://home.broadpark.no/~rbrekne/ricmain.html">http://home.broadpark.no/~rbrekne/ricmain.html</A>  </html>