Del, I would say that if your instrument has a 15 second sustain time, it's pretty good right there. After all a piano is a percussive instrument. But we are looking for a Singing Tone. I think the effect is much more noticeable on pianos whose sustain time is less than that, like five seconds which suggests that the duplex scale harmonic bridges are improperly placed. Testing the duplex scale on a piano with abridged sustain in most cases reveals that they are out of tune. My experience and that of the techs in a number of my seminars, especially the latest ones in which a beautifully prepared piano was the specimen, is that the sustain can be improved from five seconds to 30 seconds or more when the duplex scale is tuned. Dan Franklin
This PTG archive page provided courtesy of Moy Piano Service, LLC