As with many things in the piano, the function of the 'tuned duplex' is frequency sensitive. The termination efficiency varies with lengths of the vibrating wave in the strings. In the notes just into the capo tastro area the partial to which the duplex is tuned is quite short (relative to the speaking length); very little vibrating energy below the frequency of this partial gets through so, if it is damped, very little vibrating energy below this partial is damped out. Further up the scale this changes as the duplex is tuned to lower partials (again, relative to the fundamental speaking length). ddf Delwin D Fandrich Piano Design & Fabrication 6939 Foothill Court SW, Olympia, Washington 98512 USA Phone 360.736.7563 — Cell 360.388.6525 del at fandrichpiano.com — ddfandrich at gmail.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of David Love Sent: Wednesday, March 16, 2011 6:36 AM To: pianotech at ptg.org Subject: Re: [pianotech] Tuning the duplex sections It does seem, however, that it's more than just the length of the sustain that changes when you mute the longer front duplex and something in the quality of the sound itself. That energy while in the front duplex must produce it's own contribution to the sound even if it's something short of what you would characterize as noise. Further, why doesn't one hear a more pronounced difference between the last note in the tenor where there is a heavy piece of counterbearing felt and the first note in the treble with its long unmuted front duplex?
This PTG archive page provided courtesy of Moy Piano Service, LLC