This is a multi-part message in MIME format. ---------------------- multipart/related attachment ------=_NextPart_001_0018_01C48BA7.82C4EE80 Contact Ratio Is the ratio between the time the hammer touches the string and the time = the wave traveling along the string from the strike point to the bridge = and back to the strike point. If this two times are equal, one have a ratio of 1. This means that the = hammer moves away from the string as the string wave returns from the = bridge and gives therefore the maximum of energy into the first = harmonic. This contact ratio is highly dependent of the string tension = and of the hammers stiffness. Assuming a smoothed stiffness in the = hammer set will show any differences in the scales strike point = stiffness.=20 Unfortunately strike point stiffness of the strings of a key can not be = taken in correlation to contact time (and therefore contact ratio) on = the break from bichords to trichords, since the hammers damping loss is = different if there are 2 or 3 strings. So any theoretical calculation of = contact time with static formulas go far off from whats happen real. With the dynamic model of Mensurix one can measure a realistic contact = time. The Reference Graph allows you to make a sound classification of two = different instruments. Or you can use the contact ratio to set your string diameters at the = breaks to achieve a better sound balance. On the graph below, the Example 1 curve is from a Hamburg grand piano, = and Example 2 is from a Vienna grand piano (modern scale). One can see, = that around the break the contact ratio of the Hamburg piano (a scale = from 1880) lies nearly on a straight line indicating a well balanced = sound that will keep its line also if the hammers intonation becomes = lost in time. A jump at the break of the the contact ratio may be = needled out to some amount, but when the hammers intonation has gone, it = will return. A relative sound classification can be seen in the Graph 2 (with Hamburg = as grey curve in reference) directly since around the break and the = upper bass region on the Hamburg model the contact ratio is higher = (produces a more bass pronounced sound), wheras on the Vienna model has = less contact ratio resulting in a more harmonics pronounced sound in the = bass region. This must not be a question of quality, but shows the = instrument specific sound characterization. The blue line in the graph marks the break, (on the keyboard the red = marker) best regards, Bernhard Stopper more info: http://www.piano-stopper.de/html/mensurix_51.html ------=_NextPart_001_0018_01C48BA7.82C4EE80 An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/85/c5/fd/7a/attachment.htm ------=_NextPart_001_0018_01C48BA7.82C4EE80-- ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 83258 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/ec/3a/02/3f/attachment.jpe ---------------------- multipart/related attachment--
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