Dale, Let's see how many pitches you have thrown that I can hit. 1. Are the front duplexes tuneable If they are moveable , they are tuneable. 2. How do you determine the tune? Duplex Scale segments were designed to be "oliquot" portions of the speaking length. That is, a half, a quarter, a third, an eighth, etc. The principle of acoustics of Duplex Scale tuning is to use the ear to find the closest and lowest partial of the speaking length that that portion corresponds to. Such as an octave ( for half) a double octave ( for a quarter) etc. You will note that these intervals correspond to the sequence of partials, which is exactly what they were designed to do by helmholtz and Steinway. 3. BuzZing duplexes. If by testing it can be ascertained that the duplex portion of the string is causing a buzz, the simplest remedy is of course to mute it. However, I have never heard or seen any scientific data or experiment that proves that tuning the duplex causes the buzz. I highly doubt it. However it may be possible that the bearing of a duplex scale does not conform to mfg specs and altho the duplex may be in tune, the bearing may be insufficient producing a buzz. But this is conjecture on my part. I do not have sufficient experience with buzzing duplexes to make a categorical statement on this subject. Dan Franklin, RPT
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