Duplex

[Duplexdan@AOL.COM]

Dear Don,

With all due respect to your credits which seem impressive, AMUS, RMT, RPT, 
ETC,

your interest in duplex scale tuning should be referred to other technicians 
with greater credits than mine. I refer you to Hermann Helmholtz and CFT 
Steinway. they invented the duplex scale. My only contribution is developing 
a method to tune it.

As far as band pass filters absorbing frequencies, I cannot comment. I can 
only state with twenty years of experience and limitless backup, that tuning 
the duplex scale of duplex scale designed pianos contributes to the sustain 
and quality of tone of these pianos.

Dan Franklin, RPT