longitudinal mode?

[Andrew and Rebeca Anderson]

Yup,
Already had that problem and a short concise conversation with Bill 
Youse (sp?).  He mentioned using a rubber mallet to seat the 
cross-strut and tightening the screws down.  Did both and the screw 
didn't move or help so I seated it with thicker CA.  (cringe, I was 
desperate with an artist breathing down my neck)  It worked 
fine.  Will probably take a solid tap to get it out now, but then who 
and why would it be removed?

Andrew Anderson

At 01:07 PM 10/8/2007, you wrote:
>Well, its not anything to do with the longitudinal mode. For such a 
>high string thats out of the question.  You might check the cross 
>strut.  I had a D here in town that was causing a similar sound on 
>C6.  Only C6 would excite it... but when you played C6 reasonably 
>hard boy was that buzz loud. Three techs tried different things 
>including one who decided to mash the strings into the bridge 
>surface in what was the most aggressive string seating job I've seen 
>in a long time.  Another tried tightening the <<bell>> screw which 
>very temporarily fixed the problem... which pointed me in the 
>direction of the cross strut when I got finally called.  A bit of 
>banging around with the palm of my hand and I found that the cross 
>strut was the culprit.  I ended up removing the thing, bushing the 
>ends with some thing felt and reinstalling it with as tight a screw 
>as I could get.  Problem disappeared permanently.
>
>Buzzes can come from all kinds of places however... in and out of 
>the instrument... and you could swear you hear where its coming from 
>and be totally wrong.  Hinges are likely culprits as is the lock mechanism.
>Good luck hunting it down.
>
>Cheers
>RicB
>
>
>    I tuned this piano again a few days later for a master class.  The
>    lid had been restored and the percussion equipment was all gone by
>    that time.  I could not find that elusive buzz anymore.  Either
>    something in the hinges (hinge-pins?) was sympathetically vibrating,
>    or more likely the snares right up close to the rim were doing
>    it.  Funny thing is, I could of sworn it was coming from inside the
>    piano.
>
>    Chalk another one up to "experience"
>    Andrew Anderson
>
>    At 07:36 PM 9/30/2007, you wrote:
>     >All strings of the unison excited the same short buzz about an
>     >octave +.  Had me chasing around a while for something but I
>     >couldn't isolate a sympathetic resonance.  I didn't think of lifting
>     >because all three were making the sound.  I could try it.  I did
>     >lift and level these strings last year.  The piano is on full
>     >climate-control with a cover most of the time and there has been
>     >very little variation in pitch.  I noticed it today with the lid
>     >off.  It was right next to the snares but the sound sure seemed to
>     >come from within the piano.  I'll have to check again when the
>     >orchestra instruments are distributed back to their classrooms/owners.
>     >
>     >Andrew Anderson
>     >
>     >At 03:36 PM 9/30/2007, you wrote:
>     >
>     >>>Tuned a D this afternoon to prep for this afternoon's
>     >>>concert.  A#6 had a short buzz a harmonic above the note.  I could
>     >>>not find an offending duplex (front/back) to mute.  Would this be
>     >>>a longitudinal mode?  Got any ideas to chase this one down?
>     >>>Andrew Anderson
>     >>
>     >>Hi Andrew,
>     >>I'd think not. The longitudinal would be way up there in pitch, and
>     >>I'm not sure they're even audible that high in the scale. Did you
>     >>isolate unison strings to see if only one made the noise? I'd try
>     >>repositioning the strings a tad, and lifting and leveling that
>    unison.
>     >>Ron N