The Z factor is refers to loudness (not the precise scientific explanation). To be honest, in my experience, small changes in the Z factor or bumps in the scale are not that noticeable. If you are making little changes on the existing bridges you are somewhat limited in terms of getting everything to go smoothly: tension, Z, inharmonicity. You probably have to choose where to emphasize or compromise. There are differences in opinion on this. My own scale design efforts have been largely influenced by Fandrich and Nossaman. My recommendation if you are a beginning student in the scaling arena is to pay someone to consult, observe and ask questions. That's what I did for many many sets and I still like to run it by someone to make sure I'm doing something weird (or dangerous) or just for another set of feedback. David Love www.davidlovepianos.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Porritt, David Sent: Sunday, May 24, 2009 10:00 AM To: pianotech at ptg.org Subject: Re: [pianotech] Steinway A Bass String Rescaling David: I'm going to make a little change this summer on a piano and I'm very much a beginning student in this area. I understand most of the factors you're talking about but I'm not sure what difference I am going to hear with a change of Z. 'splain please! dave David M. Porritt, RPT dporritt at smu.edu -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of David Love Sent: Sunday, May 24, 2009 10:33 AM To: pianotech at ptg.org Subject: Re: [pianotech] Steinway A Bass String Rescaling Since different pianos have a tendency toward a particular scale design--high, medium, low tension--the absolute inharmonicity values will be a function of that particular scale. Other than transitional modifications, you probably don't want to deviate a lot from the original intent of the pianos design in this respect (there are exceptions--take original Knabe scales for example). In other words, it's not best to convert a Steinway (low tension) to a high tension scale for reasons relating to general tonal character, soundboard deflection designs and plate capacity to take additional tension. Thus, the absolute inharmonicity values for the plain wire section will be somewhat given. Any changes there will likely be very minor and will pay attention to other factors. Moving through the low treble and into the bass you will want to tie all the factors together for a smooth transition as much as possible: tension, inharmonicity, Z, and to a lesser degree BP%. Between each section, plain wire to bichords, and bichords to monochords, there will be some jumps and you have to choose which of those factors is more important in terms of how this will all sound which forces you to consider which factors you actually hear when you are able to compare them butted up against another section where there is some type of transition. As Ron and others have mentioned, you don't really hear absolute inharmonicity values. Problems with inharmonicity become evident only in tuning adjacent but different sections. Different scale designers choose to emphasize different factors in their decision making process especially when working with original bridge layouts that require more and greater compromises than were you to lay out a new bridge or modify the existing one with added transitions, changing bi-chord/monochord transition point, etc. For example, you can hear tension changes as evidenced when you listen to the bottom end of the plain wire section of a Steinway B comparing it with notes a little farther up the scale. You also hear tension and Z factor differences when, again, you compare the bottom end of the Steinway B long bridge against the notes at the top of the bass bridge (soundboard response differences notwithstanding). While those differences also influence the inharmonicity between those two sections, you don't really hear that as a qualitative difference. Emphasizing inharmonicity at the expense of other factors is probably a mistake in terms of how well the piano blends and balances. David Love www.davidlovepianos.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of William Truitt Sent: Saturday, May 23, 2009 4:17 PM To: pianotech at ptg.org Subject: Re: [pianotech] Steinway A Bass String Rescaling "we don't hear the inharmonicity in pianos. ... too much emphasis is still being put on absolute inharmonicity values in scaling." So Ron, this meants then, that you would favor a scale with no inharmonicity, right? (I KNOW that I'm being bad, but I can't help myself...) Will
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