<table cellspacing="0" cellpadding="0" border="0"><tr><td valign="top" style="font: inherit;"><div>Please allow me to point out, Kind Sirs, that the function of simple tuning fork exhibits those traits of energetic transmission/transmutation that some members of this list seem to discount as fantasy: specifically, that when the ball at the end of a tuning fork stem is simply, gently pressed (with no solid mechanical coupling) against some object (and with the briefest of all possible contact points) energy is transmitted from the laterally oscillating tines well ABOVE that point TO that object; which then transmits them to the the surrounding air, resulting in sound of a louder volume than the tines alone impinging on the air create. And that this phenomenon will transpire even if the object thus pressed against is a distinctly non-diaphragmatic -- as we normally conceive it -- one, such as a cube. I thus find it implausible that such an easily observed phenomenon would not find expression in a structure as large, solid, and rife with vibratory excitement as that which a piano presents. Regards, Thumpe</div></td></tr></table> <div id="_origMsg_"> <div style="font-family:arial, helvetica, sans-serif:font-size:10pt"> <div style="font-family:times new roman, new york, times, serif;font-size:12pt"> <hr size="1"> From: David Love <davidlovepianos@comcast.net>; To: <pianotech@ptg.org>; Subject: Re: [pianotech] Totally glueless Sent: Thu, Jan 31, 2013 4:12:06 PM <table cellspacing="0" cellpadding="0" border="0"> <tbody> <tr> <td valign="top" style="font:inherit;">Seems there are two separate questions:  one of efficient and permanent coupling of the bridge to the board, the other is the mechanics of the how the sound is transmitted.  Given a reasonably tight coupling of the bridge to the soundboard with screws the acoustics would seemingly not suffer, at least not audibly and not as long as the joint remained tight: as the bridge moves so does the board.  Whether there is, without the benefit of a rock solid glue joint, some even fractional movement (friction) in which some of the energy at some frequency(ies) might not be dissipated in the form of heat is for more refined measuring devices than our ears will surely deliver.  That we aren't able to discern the loss with our ears doesn't mean there may not be some.  Some answers are complicated, especially those that lead to other questions, and I don't think denigrating legitimate inquiries is a very good path to knowledge.  Needless to say, it's best to glue the bridge to the board.    David Love www.davidlovepianos.com -----Original Message----- From: <a ymailto="mailto:pianotech-bounces@ptg.org" href="javascript:return">pianotech-bounces@ptg.org</a> [mailto:<a ymailto="mailto:pianotech-bounces@ptg.org" href="javascript:return">pianotech-bounces@ptg.org</a>] On Behalf Of Ed Foote Sent: Thursday, January 31, 2013 6:06 AM To: <a ymailto="mailto:pianotech@ptg.org" href="javascript:return">pianotech@ptg.org</a> Subject: Re: [pianotech] Totally glueless Ron writes: People have an absolute genius for complicating anything and everything and feel compelled to invent detailed explanations whether they have any facts or logic to work with or not. It's intuitive, instinctive, and fundamentally irrational. It's also nearly universal. "I've heard", "I was taught", "I believe", "it's obvious", "simply", and "stands to reason" are the enemies. Innate contradictions like the glue joint blocking sound, while a loose joint not passing vibrations because there was no glue with the screws, should be questioned.>>   Ok,  a question, then.  Do you glue your bridges to the soundboard, and if so, why?  I don't think a pair of screws couples the bridge adequately to the soundboard, either mechanically or acoustically, but if there are reasons why that coupling isn't worth questions, I would love to hear them. Regards, Ed Foote RPT <a href="http://www.piano-tuners.org/edfoote/well_tempered_piano.html" target=_blank >http://www.piano-tuners.org/edfoote/well_tempered_piano.html</a>   </td> </tr> </tbody> </table> </div> </div> </div>