This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Hello Stephane, is it possible for you to send me length and diameters for the keys that = causing the problems? I will do a dynamic simulation and a sound simulation with the Minimens = to find out what might be the case. Please let me know also what kind of = steel wire Kawai is using. MiniMens can do a sound simulation that = reports also the longitudinal waves. I rather think it is a problem = caused by the longitudinal waves (as Isaac Oleg metioned also earlier), = but to do an exact simulation, it is necessary to know the value of = youngs modulus of the core wire. (I actually only have it for R=F6slau = steel, it varies from 201 to 207 kN/mm=B2 depending on the diameter). I = "measured" youngs modulus of R=F6slau steel by simulating different = diameters with the Minimens Simulator and measured inharmonicity on = real instruments with same settings until the spectra fit. I don=B4t think that the problems are caused by the multiple contacts, = because they are normal for the lower keys. on the lowest octave the = hammer does bouncing with the string up to 3 or 4 times, thats normal. Best regards, Bernhard ----- Original Message -----=20 From: St=E9phane Hanriat=20 To: Pianotech=20 Sent: Friday, April 09, 2004 8:21 PM Subject: Re: Analysis of plain wire string/wound wire break on a = SteinwayModel Bwith MiniMens 1.0.6 Hello Bernhard, Very interesting post. I'm wondering if the "contact ratio" has = something related to the "kissing noise" effect I've observed on most of = the Kawai piano I've played. Please see below the post I sent to the = list on the subject. I've working with Kawai Europe & Japan to try = understanding the root cause, but they were not able to explain this = parasitic noise to me, just saying that this is well known and likely = due to hammer condition ??? I've never been convinced about that = explanation, since only very few notes are impacted (few first notes = below the break tri-cord/bi-cord) and only on the 1.78m and 1.86m = piano... Personnally, as an engineer, I already made the hypothesis of multiple = contacts with the strings in that range, creating this parasitic noise = (see below)... I would be very much interested to have your feedback on this point. Cheers, Stephane Hanriat - Owner of Shigeru Kawai SK3 ______________________________________________ Hello List, I'm back with another topic I would like to share with you. During the process of selecting my Shigeru piano, I played a lot of = Kawai instruments, and I found a strange noise impacting very few notes, = but always the same notes : 23, 24 and 25. The noise looks like a = whistling appearing at the attack, and is very easy to ear when playing = a non legato trill at pianissimo. This noise is clearly audible on most = of RX-2, SK2 (1.78 m), RX-3 and SK3 (1.86 m). Very difficult to ear it = on larger instrument. RX-6 or SK6 (2.12 m) do not have it. - sorry for = the metric unit -:) I had extensive discussions on that with our french MPA who is now an = expert to determine whether an instrument is having the noise or not. We = have contacted Kawai in Japan. They replied that this is well known as = "kissing noise" and that mostly all prestigious brands are facing this = problem that originates from hammer conditions. Kawai also told us that = Steinway has extensively studied the topic without identifying the root = cause ; and when the problem is creating inconvenience at playing, = Steinway is replacing the hammers... We made some experiments at the french Kawai show room on some RX, = without being capable to find a reliable fix. Some pianos were not = having this kissing noise, but most of them had it in the showroom. When I play grand pianos in this size range, I always discreetly check = the stuff... but I've not seen this kissing noise as present as on the = Kawai. I can tell you I've been cautious when selecting my Shigeru, so = it took me 2 years to find an SK3 almost free from kissing noise (but = not completely free). If some of you have an explanation and/or a fix, I would be very = excited to learn this (and lot of MPAs too, believe me). Cheers, Stephane Hanriat, the french guy who loves the Shigeru's. ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/38/f3/f5/69/attachment.htm ---------------------- multipart/alternative attachment--
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