Yes. The Z-Bar extends from just below the end of the treble bridge—where it is physically attached to the back structure—to a point just opposite the tenor end of the bass bridge. From just under the tenor bridge the Z-Bar is glued to the soundboard panel but not the back structure. The ribs are centered on the bridge and extend up to the Z-Bar. There are no functional ribs below and to the right of the Z-Bar although we did end up putting several thin, acoustically non-functional ribs over there to keep the solid wood soundboard panel from buckling and cracking. Description: C:\Documents and Settings\Delwin D Fandrich\My Documents\FileCabinet -- DDF\Piano Designs\Fandrich--122 Vertical\U22-Master Drawings\U22 - Iron Plate Master jpg.JPG The Z-Bar is essentially a soundboard sizing and shaping device and an impedance control device. It keeps the soundboard area small in the treble area where the frequencies are high and the system mobility needs to be restricted, allowing it to become gradually larger further down where the frequencies are lower and the soundboard needs more surface area and more mobility. Think of it as a mechanical crossover network. The lower portion of the soundboard “floats” free of the back structure giving the low end of the bass bridge the controlled mobility needed to develop sound energy in the fundamental and lower harmonics. In several demonstrations before groups of piano tuners and technicians the audience members were unable to say precisely where the bass/tenor transition took place. In one demonstration before a group comprised mostly of piano teachers and piano tuners and technicians the piano was compared note by note starting at C-88 and working down with a Bösendorfer Imperial grand; the consensus of the audience was that the little 122 cm tall vertical produced more power, along with better clarity and dynamic range down to about the last two octaves in the bass. ddf Delwin D Fandrich Piano Design & Fabrication 6939 Foothill Court SW, Olympia, Washington 98512 USA Phone 360.515.0119 — Cell 360.388.6525 <mailto:del at fandrichpiano.com> del at fandrichpiano.com — <mailto:ddfandrich at gmail.com> ddfandrich at gmail.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Gene Nelson Sent: Friday, May 18, 2012 7:26 AM To: pianotech at ptg.org Subject: Re: [pianotech] S&S K(52) Restoration Ribs fanned and perpendicular to long bridge? Does Z structure define rib length in that area? Gene -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120518/9518e143/attachment.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 15283 bytes Desc: not available URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120518/9518e143/attachment.jpeg>
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