Soft blows

[Dean May]

Doesn't the need for hard blows vary with the scale design? Seems to me that
some pianos would be impossible to tune with stability without employing
hard test blows.

Dean
Dean May             cell 812.239.3359
PianoRebuilders.com   812.235.5272
Terre Haute IN  47802

-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On Behalf
Of Jenneetah
Sent: Tuesday, October 26, 2004 7:31 PM
To: Pianotech
Subject: Re: Soft blows

At 9:26 AM -0700 10/26/04, jason kanter wrote:
>One of the very first basics we learn is that we must set the pin
>with a firm blow to equalize the string tension across the friction
>points. How does this relate to the current discussion of using
>rather soft blows to tune unisons? I *imagine* that you tune with
>soft blows, then settle the pin with a hard blow, then listen again
>with soft blow to ensure the tuning has not moved? But the hard blow
>has likely changed the tuning, so ...

Why assume this? A clean unison before the hard blow, which remains
clean after the hard blow (and this happens more reliably as we get
better) is contradiction of this assumption. What's more, it's a
clearly achievable goal. And considering that it's inside the
speaking length that the hard blow does its damage, would the
speaking length stay steady, and some other portion of the string
path have its tension changed. If the unison is clean before and
after the test blow, it's solid. The test blow has done nothing to
alter that.

>If we avoid hard blows entirely, surely the piano will be
>immediately put out of tune by the pianist?

I thought for a long time that this was a myth, but so far have been
unwilling to bet my career on a solo recital tuning, based only on
soft blows (finger on the key at a dead stop). I am convinced that,
while tuning stability does require a certain balance of string and
pin friction from the piano itself, when it comes to the human tuner,
tuning stability is far more in the hand on the hammer than the hand
striking the key.

The "bump-up-bump-down" is what I trust.

At 1:22 PM -0400 10/26/04, Don wrote:
>I believe there have been demonstrations of the lack of ability to equalize
>tensions across the segements by bashing on the keys at conventions. I've
>not seen one in person but I seem to remember it being mentioned on the
>list before.

Ten years ago I measured the side view of note C5 on a Steinway Band
the maximum vertical displacement on that note caused a hard blow,
and fellow NH chapter member Doug Kirkwood and I calculated the
string friction barrier at the capo and the momentary tension spike
of a test blow. 21 lbs vs. 3.5 ounces respectively, as I remember. I
invite someone else to run this calculation.

At 8:04 PM +0200 10/26/04, Quentin Codevelle wrote:
>I asked my yam teacher who is a concert tech (of course) if he had
>enough stability with soft blows even with "heavy hands". He told me
>there was no problem at all, like andre says, it is the tuning
>technique that seems to make the difference.

Agreed.

At 11:33 AM -0700 10/26/04, jason kanter wrote:
>Does step 2 -- the very hard staccato blow -- damage the beauty of the
unison?

Jason, can you clarify? Are you asking if a unison played softly
immediately following the vhsb will have its beauty damage (assuming
no change in the tuning of the unison)? Or simply whether a note
sounds ugly when banged? (I'm assuming the latter, although Andre in
his answer didn't seem to distinguish.)

>Maybe the very hard staccato blow is only necessary when the string
>has been moved more than a very little bit?

As Don says, the more wire you move the better an insurance policy
the test blow is.





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