Software questions MiniMens

[Bernhard Stopper]

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Isaac,

Tomorrow i will have a new version of the MiniMens (1.0.3) where you can =
change the 25 % for security in a range fromn 0 % to 50 %. Hope this is =
helpful.
Thank you for the spectraplus link, it works very fine. I arrived to =
refine adjustment for youngs modulus. Very exciting to "measure" youngs =
modulus via measurement of transversal and longitudinal modes.

I also added a much better hammer model now, sounds nice.
To your question how to interpret the dynamic results:
I have found that on good grand pianos the simulated dB difference from =
the last 3 blank wire is about 3 dB less than for the 1. two wound =
strings. (6 dB difference is double in loudness) This may be caused by a =
more ineffective energy ratio for bass hammers on a grand because the =
hammer head is longer and therefore there is much more loss in the =
center pin (perhaps you remeber the discussion about center of =
percussion), a short hammer head length comes closer to the optimal =
point. After that, on upright pianos, there should be less difference, =
because hammer heads are shorter in relation to the blank strings. =
Actually, the MiniMens hammer model does not include hammer head length =
difference. There may be also more losses on bass strings due to the =
ripped surface, when the hammer glides on the string, what is also not =
included in the model. Losses due to the copper wrap is included now in =
the new version, you can specify a Quality factor for wound and core =
material now. Default Q value for copper is 400, and 1100 for the =
roeslau core. (measured tension free, in vacuum).  So dB level =
difference from bass to blank measure part should be interpreted =
carefully and set with reference to good instruments.

Regards,

Bernhard Stopper
www.piano-stopper.de/homepe.htm


  ----- Original Message -----=20
  From: Isaac sur Noos=20
  To: Bernhard Stopper=20
  Sent: Tuesday, January 13, 2004 11:16 AM
  Subject: RE: Software questions


  Bernhard
    Here is the data we have on type 1 & 2 strings -I'll have to =
understand how to enter #25 value so the computation uses only 15% less =
on the breaking strength limit.

    Bests regards.

    Isaac
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