<HTML><HEAD> <META charset=US-ASCII http-equiv=Content-Type content="text/html; cha= rset=US-ASCII"> <META content="MSHTML 6.00.2800.1106" name=GENERATOR></HEAD> <BODY style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; BACKGROUND-COLOR: #fffff= f"> <DIV> <DIV>In a message dated 10/3/2004 10:15:05 PM Pacific Standard Time, sarah@g= raphic-fusion.com writes:</DIV> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue = 2px solid"> <DIV><FONT face=Arial size=2>Question:  As long as I use reasonable= care and don't tear up the fiber structure of the hammer, is all needling r= eversable with ironing and/or age hardening?</FONT></DIV></BLOCKQUOTE></DIV> <DIV>Sarah,</DIV> <DIV> </DIV> <DIV>No. The purpose of needling is to "unfelt" the felt, deep in the hammer= . Ironing and use can cause the surface fibers to relax and compact somewhat= , but the genie is out of the bottle deeper down. </DIV> <DIV> </DIV> <DIV>Needling lowers the stiffness of the hammer by separating fibers, there= by shifting energy to the lower partials. The trick, of course, is to stop a= t the right point, where the mass and stiffness match for best spectrum. &nb= sp;As the mass of the hammer is reduced later by filing, the spectrum bright= ens up, and more needling can be required.</DIV> <DIV> </DIV> <DIV>Another effect of needling is related to the "battery voicing" that the= Europeans talk about. In some hammers, the inner felt is so "felted" t= hat it doesn't act like a spring at all, but mass only. In this case, the so= und may be bright but choked. Loosening up the tight inner felt will increas= e power by increasing the resilience (ability of the hammer to store and rel= ease energy efficiently), thereby increasing the fundamental, while still ge= tting the hammer off the strings and allowing some upper partials for color = (some of the compression is released from the deeper part of the h= ammer, increasing the compression near the surface). European hammers t= end toward being a little too tight intentionally, so that the voicer can&nb= sp;manipulate internal tension to taste.</DIV> <DIV> </DIV> <DIV>Spoken as a voicer, not a scientist, with respect for your scientific k= nowledge.</DIV> <DIV> </DIV> <DIV>Bob Davis</DIV></BODY></HTML>