[pianotech] What's causing this vibration?

[Laura Olsen]

Damper wire?  Sympathetic vibration with something else in the room?  Something on the soundboard?

Laura
On Mar 9, 2012, at 5:59 PM, Rebecca and John Silva wrote:

> Hi,
> 
> When playing a particular note on a piano I saw today (Baldwin L) a harsh vibration would sound. The vibration would only happen for a moment (1/4 second?) even while the note continued to sound, it was about 1/2 the volume of the note and only happened when playing hard. I worked with the owner for about an hour trying to figure it out and we were only able to determine it is based on pitch—if I detuned the note it would go away, and if I detuned the adjacent note to the offending pitch that new note would cause the vibration. 
> 
> I looked at everything I could, ensured every part/screw I could see was not loose, tapped on the bridge pins, and tried to figure out where the vibration was coming from.
> 
> Does anyone have any suggestions of where to look? Any common but elusive offenders? Two highly regarded technicians in the area were also apparently unable to figure it out.
> 
> Thanks!
> 
> John