----- Original Message ----- From: <ETomlinCF3@AOL.COM> To: <pianotech@ptg.org> Sent: Tuesday, December 21, 1999 3:44 PM Subject: Re: Duplex Scale Tuning > What a load. Take a piano with a good duplex and play it with and without > the duplex muted and the difference is very noticeable. How can one say that > it is a marketing plan? Lost energy ... we even see energy transferring into > the plate and almost all other components. > > Ed Tomlinson > ----------------------------------------------------------- That rather depends on what is used to mute the tuned duplex and how the muting is done. If something soft -- like a loose felt strip -- is used, yes, there will be losses. With the standard "tuned duplex" design there is quite a lot of energy transferred to the string segment between the V-bar and the counterbearing bar. Some of this energy is ultimately fed back to the normal speaking portion of the string, but the rest of it is dissipated into the plate and is absorbed as heat. When felt is used to mute out this segment it acts just like a damper so there will be a loss of sustain. Sometimes this loss is significant. If, however, the muting is done with something rigid -- like a brass rod, or bar -- then, no, there will be no discernable losses and the string termination will be improved. Even better, if the string deflection angle can be increased and/or the length of the duplex segment made shorter -- it is now no longer "tuned" and it is no longer vibrating significantly -- then string termination will be improved and sustain will not be adversely effected. Indeed, it may well be improved. Del
This PTG archive page provided courtesy of Moy Piano Service, LLC