Dean's explanation of the conservation of energy issue expresses my point in a better way. David Love davidlovepianos@comcast.net -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of David Love Sent: Saturday, October 02, 2004 7:19 AM To: 'Pianotech' Subject: RE: Evidence of overlacquered hammers I believe that is a misunderstanding or misapplication of the conservation of energy. The amount of energy put into the key is only one factor. The mass and/or density of the hammer is another factor, as is the amount of flexing in the key and hammer shank (since this is a dynamic system), and probably some other things to consider in terms of calculating how much potential energy is in the system and can be imparted to the string. Energy conservation refers only to the total potential energy within the domain and that it remains fixed. There is no question but that the mass of the hammer influences the amount of potential energy in the system. The hardness of the hammer is a separate issue. While it doesn't influence the potential energy in the system (given two hammers of equal mass) it does influence how efficient energy can be transferred to the string and how much might by converted to some other form (heat I suppose) which is absorbed by the hammer (non technical explanation here). But that's the general idea. David Love davidlovepianos@comcast.net -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Bernhard Stopper Sent: Saturday, October 02, 2004 6:23 AM To: Pianotech Subject: Re: Evidence of overlacquered hammers David, Yes thatīs what i say. As long as you put the same amount of energy into the key, the sound will not be louder. This the principle of conservation of energy. Bernhard ----- Original Message ----- From: "David Love" <davidlovepianos@comcast.net> To: "'Pianotech'" <pianotech@ptg.org> Sent: Saturday, October 02, 2004 2:34 PM Subject: RE: Evidence of overlacquered hammers > What you are saying then is that heavier and/or harder hammers do not > make the sound louder except by the excitement of a different set of > partials. That's just not the case. I'm sorry but I believe you are > misinformed on this. But don't take my word for it, ask a physicist or > an engineer. The amount of energy imparted to the string which is > transferred to the soundboard is a function of mass and/or density of > the object striking the string. > > David Love > davidlovepianos@comcast.net > > -----Original Message----- > From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On > Behalf Of Bernhard Stopper > Sent: Saturday, October 02, 2004 1:21 AM > To: Pianotech > Subject: Re: Evidence of overlacquered hammers > > David wrote: > > >A panel which > >moves less efficiently will require more mass, density or both from the > >hammer in order to achieve the same displacement of air by its motion > >than a panel that moves more efficiently for which a softer hammer will > >achieve the same result. > > No i donīt agree, because there is the string between the soundboard and > the > hammer. If the string is too thin, more mass in the hammer has no > possibility to arrive at the soundboard. > > Bernhard > > > ----- Original Message ----- > From: "David Love" <davidlovepianos@comcast.net> > To: "'Pianotech'" <pianotech@ptg.org> > Sent: Saturday, October 02, 2004 2:40 AM > Subject: RE: Evidence of overlacquered hammers > > > > My understanding is that the soundboard is a transducer, not an > > amplifier--there is no added energy--it's function is to convert > energy > > of the vibrating string into a larger moving body which has the > ability > > to move the air which the string by itself does not possess in > > sufficient quantity. The panel's ability to do that is a function of > > several factors including: panel thickness, rib dimensions and > > stiffness, crown, spring rate, type of rim, location of bridges and > > probably other things which I have forgotten. Not all soundboards > will > > move with the same efficiency and some will move too much--or some > areas > > of the panel will. The hammer imparts a blow to the strings and the > > energy imparted is a function of hardness, mass or both. A panel > which > > moves less efficiently will require more mass, density or both from > the > > hammer in order to achieve the same displacement of air by its motion > > than a panel that moves more efficiently for which a softer hammer > will > > achieve the same result. How the partials develop is a somewhat > > different issue, which I am not addressing here. > > > > So, if not all panels are created equal, then one hammer will not > yield > > the same result on different panels. How much different the panels > need > > to be to be able to hear that is another issue. > > > > David Love > > davidlovepianos@comcast.net > > > > -----Original Message----- > > From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On > > Behalf Of antares > > Sent: Friday, October 01, 2004 12:52 PM > > To: Pianotech > > Subject: Re: Evidence of overlacquered hammers > > > > > > On 1-okt-04, at 21:41, Bernhard Stopper wrote: > > > > > The time, the hammer is in contact with the string is the main > effect > > > of how > > > many partials and in what weight they will occur. The soundboard > > > itself has absolutely no possibiliy to add any partials to the > strings > > > spectrum (except the short shock spectrum caused by the hammer > impact) > > > > > and > > > acts only as an amplifier and filter. But the oscillator is the > > string. > > > > > > best regards > > > > > > Bernhard Stopper > > > > > > > Exactly. Thank you for your clear explanation Bernhard! > > > > André Oorebeek > > > > _______________________________________________ > > pianotech list info: https://www.moypiano.com/resources/#archives > > > > > > _______________________________________________ > > pianotech list info: https://www.moypiano.com/resources/#archives > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
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