Richard Brekne wrote: >How about useing a bandpass filter set to around the frequency >of the partial you are trying to narrow in on in line between the pick-up >and an amplifier, then returning the resulting sound to the soundboard via >a contact transducer. Good old fashioned feedback, but a bit more >controlled ? Is is possible to "drive" a partial in this manner ?? Dont >laugh too loud now guys.. after all I am still just an egg in these >matters.. The problem with what you describe is that your bandpass filter / feedback combination now becomes part of the resonant system. Thus the resonant frequency will be affected (i.e. "pulled") by the filter tuning. You will no longer be measuring something that is purely representative of the piano. In the studies I have done, the strength of the partial is not a limitation (unless you are trying to measure inharmonicity in the presence of high background noise). And if a partial is really really weak, who cares what its frequency is? No one will hear it. -Robert Scott Ann Arbor, Michigan
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