<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Piano Firing Missiles at Church Congregation</title></head><body> <div>Bill Bremmer wrote;</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">. . .  I need some opinions on what to do about it.  It is a</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">Young Chang Grand model G-185, only a few years old.  It is meticulously</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">cared for but early in it's service, the pianist at this, shall we say,<br> "spirit filled" church complained of bass strings breaking and shooting out</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">of the piano.</font></blockquote> <div><br></div> <div>Broken bass strings shoot out of the piano when the string breaks at the agraffe and the hitch pin is angled back suitably to steer the projectile-string out of the piano. Bosendorfer Imperials are famous for this, breaking at note C4  (in the Bos' this note is actually not the forth string on account of the extra bass notes) which is strung at nearly 400 lb tension with 1.35 diameter core wire. I've had two Cs go off and frighten the hell out me. I actually tune these pianos with my body off the line of the string to avoid wearing it.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">I have tried all of the usual.  I filed the hammers.  </font></blockquote> <div><br></div> <div>This is not the problem</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">A monitor feeds back</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">sound to the pianist.</font></blockquote> <div><br></div> <div>This will help.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">When I explained to the church directors that it is</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">the "vigorous" style of playing that sometimes causes strings to break, the</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">pianist resigned.  . . . . . . . .</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1"><br> I am thinking that these wound strings must have particularly high tension.  </font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">Does anyone know if this is so?</font></blockquote> <div><br></div> <div>The tension is not the problem. The pianist may be part of it, but not all. Very often, small grands are built with rediculous string angles at the front bearing bar between the tuning pin and agraffe (in the bass only). While these angles can be tolerated in a home piano which might only be tuned biennially, when such a piano is tuned every other week it will invariably develop wire fatigue at the bearing bar and agraffe.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">Over the years I have heard of other such</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">instances that were cured by replacing the wound strings with a set of<br> lighter gauged, "happy" strings.  It would seem to me that a lower tension<br> would solve the problem but in reading the recent post about "replacement<br> strings", I am confused.  Some of these strings have been breaking at the<br> bass bridge termination point rather than the agraffe.  That seems very<br> unusual to me.</font></blockquote> <div><br></div> <div>Wire breakage at the bridge would tend to indicate that the wire is fatigued through playing also. Church pianists, like the congregation, can get pretty overenthusiastic at times. The feed back monitor can help here.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">Should the manufacturer supply a new set of wound strings and if so, should</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">they be a set designed for lower tension?  I presume that heavier gauged,</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">higher tension strings provide a bigger, bolder sound.  </font></blockquote> <div><br></div> <div>A heavier wrap will produce a 'fatter', longer piano sound, while a heavier core will raise the inharmonicty to produce a more 'growly' tonal quality. The G185 bass is not a particularly high tension scale (no piano with a 135 cm speaking length can be). I would advise against rescaling. In any event, it's not necessary. The problem lies elsewhere.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">What effect would</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">lower tension have?  Just as a theoretical question, would tuning the</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">instrument to a lower pitch, say 100 cents lower prevent this from happening</font></blockquote> <div><br></div> <div>Percentage of breaking strain !!! The use of a lower tension bass will not only give the piano a 'gutless' high inharmonicity bass, but it will lower the percentage of breaking strain of the bass section (particularly if the same core wire guage is retained), resulting in a slight reduction in the tuning stability in response to temperature and humidity variations. Mind you, there should be some percentage of breaking strain variation when the string scale crosses from trichord plain to bichord covers to facilitate tonal equality at the cross (there should also be a reduction in speaking length of between 10 - 15% at this point also - it is for this reason that pianos which use bichord covers for last couple of notes on the treble bridge, without any step reduction in speaking length, are always a scaling disaster)</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">It is also interesting to note that to date, only wound strings have broken,</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">no plain wire.</font></blockquote> <div><br></div> <div>You will also be interested to observe that the extreme string angles, caused by the too-high bearing bar, only occurs in the bass. If you restring the bass and reduce the bearing bar height to reduced the string angle deflection to 15 degrees or less (I prefer around 12.5 degrees), the problem will go away. Don't forget to replace the agraffes as well, the silly string angles will have destroyed the agraffe string hole shape (just cut one through the lower half of the holes with a hack saw and investigate the upper bearing surface with a looking glass - you will be astonished at the damage). We have done this bearing bar fix many times to small Kawai and Yamaha grands in commercial service - to good effect.</div> <div><br></div> <div>Regards,</div> <div><br></div> <div>Ron O</div> <div><br></div> <div><br></div> <div>-- <br> Overs Pianos<br> Sydney Australia<br> ________________________<br> <br> Web site: http://www.overspianos.com.au<br> Email:     mailto:ron@overspianos.com.au<br> ________________________</div> </body> </html>