Pianotech

Assistance with recordings of Equal Temperament tests on instruments for "chromosone" research

  • 1.  Assistance with recordings of Equal Temperament tests on instruments for "chromosone" research

    Posted 04-10-2021 11:07
    Currently I'm looking at the ways in which a tuned piano resonates, and the frequencies permitted by the tuning, harmonics and inharmonics, producing graphs or charts of sonic responses that look like chromatographs, so examining "chromosones" rather than chromosomes.

    For the past decade and more, my focus has been on Unequal Temperament and developing what I call a "high definition" tuning. Attached are a couple of graphs that some might find of interest, of the large model 1885 Hammerwood Bechstein and a 1980s Steinway M which I tuned yesterday. The chart "Steinway M fundamental and triads chromatically ascending C0 C3 E3 G3" might express why I call the results "chromosomes".

    Whilst being experienced with Unequal Temperament I don't have much to do with getting Equal Temperament sounding its best.

    I'm wondering if anyone might be able to help me with some recordings to analyse of an instrument newly tuned in good Equal Temperament on the Railsback curve as well as tuned to ET on a P12 basis? Whilst I can do something with an instrument with a machine it would be better to look at the results from an instrument tuned by someone to bests standards.

    Ideally the recording is Mono rather than stereo and for analysis the software I'm using requires conversion to 16000 samples per second rather than CD standard 44.1kHz but I can do that conversion.

    I'm looking at two recordings, sustain pedal down all the time:
    1. Octave groups of notes all at once, so 
    a. A0 Bb0 B0 C1
    b. all notes together C#1 to C2
    c. all notes together C#2 to C3
    d. all notes together C#3 to C4
    c. all notes together C#4 to C5
    c. all notes together C#5 to C6
    all held down until sound fades up to 20 seconds.

    Then,
    2. fundamental and triads so
    C0 G2 C3 E3 or C0 C3 E3 G3 (I did former on the Bechstein and latter on the Steinway but it doesn't make a lot of difference looking at the C3 to C5 spectra)
    going up semitones for two octaves 

    From my results with the Pleyel Chromatic harp, the comparison may well be quite visually interesting.

    Best wishes

    David P

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    David Pinnegar BSc ARCS
    Hammerwood Park, East Grinstead, Sussex, UK
    +44 1342 850594
    "High Definition" Tuning
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