Singing Strut

[C. Mike Swendsen]

I was tuning a Steinway 6' last week and it has a strut that sings as
well.  The owner brought it to my attention.   I could make the tone go
vibrato by tapping on the strut.  Whe the struts are unter a lot of
compression, I believe their 'dead' tonal characteristics change.
C. Mike Swendsen RPT

Delwin D Fandrich wrote:
> 
> Charles E Faulk wrote:
> 
> > Del,
> >
> > I looked at the 6' Petrof grand today, and it does indeed have a 'singing
> > strut'. The owner was quite prepared for me. He first played E-flat 3 for
> > me, kind of a staccato hit, and sure enough the strut rang out like a
> > large tuning fork. Then he rapped the offending strut with his fist and
> > made it ring again.
> >
> > I checked for any defective damping. There was none.
> >
> > This particular Petrof has a nose bolt located at the rear of the case
> > just under the juncture of the first two long struts which flair out in a
> > V-shape to the front. The only other nose bolt is under the third strut
> > which begins the third section of the piano. Both the two long strut are
> > rather thin which I guess explains how one of them can vibrate.
> >
> > Looks like Petrof needs to do a serious redesign on their plates.
> >
> > Thanks for your input.
> >
> > Charles Faulk
> > Manhattan, KS
> 
> -----------------------------------
> 
> Charles,
> 
> Well, so much for iron being "acoustically dead" as we were always taught. I found it very interesting to see what was
> happening in the various parts of a piano plate once I was able to get an accelerometer on one. Acoustically dead, indeed!
> 
> What is being done to remedy the situation with this particular piano? Is it under warranty or is it something you and the
> customer are going to have to deal with? If the latter, feel free to contact me privately if you think my ideas might be of
> any help.
> 
> While this might be a bit tricky to solve on an existing piano, from a plate design standpoint these things are usually
> easier to fix than you might think. If this is a fluke, the manufacturer probably won't be overly concerned about it, but if
> they have had a series of complaints about the problem, then some relatively simple plate pattern changes are definitely in
> order.
> 
> Del