Measuring the soundboard crown
Cc88m
"discovered" for me -- I'd be surprised if someone else hadn't discovered it
before,
but thot I would share it with everyone.
Take a flexible ruler at least 1 ft long, and place it against the SB, anywhere
you want to measure the crown, holding the ruler in the center. If the crown
is +ve, the ruler will wiggle in the center, but the ends will contact the SB
and not move. Conversely, if the crown is -ve, the center of the ruler will
not
move, but the ends will rock. You can also shine a flashlight from behind the
ruler and visually see the size of the gap. It has the advantage over the
string
method in that you can get into spaces the hands cannot, you can do it with
only one hand, it is quick. With this method, for example, I have found that:
By using a ft long ruler, you can determine the LOCAL crown: for example,
old SBs tend to be like washboards with regions of both +ve and -ve crown.
You can quickly follow and trace ridges and cracks. You can determine the
sign of the crown that is too small to see with the string method; ie, the
ruler
seems to be more sensitive.
C. C. Chang
Rick Clark
>I've "discovered" a simple method for measuring the soundboard crown;
That's a good idea you have there, I think. I have always preferred
straightedges to string, combined with a downbearing gauge at the
bridge, but I think the "flexible" straightedge idea is nice, as it
gives a tactile sense of the gap.
Rick
To E-mail me privately remove the NO from piano...@mindNOspring.com
Frank Weston
it is only useful if one understands its limitations. With a short ruler,
you are determining the shape of one small area of the soundboard. This
information is helpful, but as you have pointed out, old, and even new
soundboards, can be quite irregular. It is the sum of these irregularities
from rim to rim that will determine total crown. Measuring just one point
with a short ruler could give drastically misleading information if only
that point were considered. The best approach is to measure in lots of
places and with different methods, then use your analytical skills to reach
a determination on the condition of the soundboard.
Here's a simple method I use when examining old Steinways: I don't measure
anything. If the plate is not cracked, and the fallboard says Steinway, and
the price is right I buy it and assume that the soundboard will be replaced.
Frank Weston
Cc88m wrote in message <19990604224357...@ng-fo1.aol.com>...
George Gilliland
where the bridge crosses octaves 5 & 6: a small area, and a very hard place to
measure with all the bracing there. I very much agree with the "sum of all
irregularities" statement. The soundboard on my piano has lots of crown, but
some very annoying impedence problems high in the scale. These can only be
fixed with an overhaul that would cost probably more than the total value of
the instrument (and possibly end up sounding worse due to other flaws inherent
to the design).
I've learned to live with the problem and enjoy the other nice qualities of its
tone and playability, but I would advise anyone to have a piano carefully
tuned, play it for a few hours and "measure" soundboard crown with his ear
instead of a straight-edge. The only person who is really in an ideal position
to measure the crown is the person who bellies the piano.
All the variables involved in piano design are a fascinating puzzle but they
can swim in a musician's mind in a truly devilish way, if they're allowed to,
and they can become very distracting to the music-making process. The first
thing is to listen. If the sound doesn't linger nicely in the ear, then all
crown in the world, an S&S on the fallboard, and five zeros on the price tag,
still have not added up to a good piano.
Well. . . I'll get lost again.
George
A440A
>some very annoying impedence problems high in the scale. These can only
>be
>fixed with an overhaul that would cost probably more than the total value
>of
>the instrument (and possibly end up sounding worse due to other flaws inherent
>to the design).
Greetings,
There are some things that can be done with impedance problems. The first
of which is to pad the jaws of small visegrip pliars and attach them to the
ribs underneath. This will change the impedance of the board. if you find a
place where the additional weight seems to benefit the tone, you can measure
out a small lump of lead with a screw hole in it, and screw that sucker on.
Alternatively, you can just kiss the visegrips goodbye and leave them on
there. Life is too short to play any worse piano than we must, and it is
the music that matters, not a few scars on the bottom of the soundboard.
(Geez, that really sounds like "old world craftsmanship, don't it...(:)}}
Regards,
Ed Foote
Precision Piano Works
Nashville, Tenn. USA
http://www.uk-piano.org/edfoote/index.html
To email me, omit ".omit"
George Gilliland
few times to find just the right spot, but got some very good results. . . Thanks
for the tip.
George
Gary Teters
little curious on your soundboard problem. What exactly were the symptoms.
Short sustain? Lack of something in the sound?
Gary Teters
George Gilliland wrote in message <3765974F...@epix.net>...
Rick Clark
> There are some things that can be done with impedance problems. The first
>of which is to pad the jaws of small visegrip pliars and attach them to the
>ribs underneath. This will change the impedance of the board. if you find a
>place where the additional weight seems to benefit the tone, you can measure
>out a small lump of lead with a screw hole in it, and screw that sucker on.
Well, this provides some brain stimulous. Do you know of any articles
on this idea I could read up on? Thanx!
Rick Clark
George Gilliland
hammers of old used to be large, but low mass, producing a mellow sustained
tone. Now, apparantly, they're using smaller, harder hammers to compete with
brighter "Yamaha" sound. He insists that the right hammers will make huge
difference in tone quality. I've since been trying to get him to answer e-mail
about how to find the right set of hammers. I've also since been doing my own
voicing with great results. But it's tedious. I'd rather have someone else
re-hammer it and spend more time playing. (BTW, in my opinion, Baldwin factory
hammers are fairly poor in quality).
Re: soundboard, in octave six several notes scatter due to overly rapid
soundboard impedence. There is also much false beating built into scale there
(which can be partly cleaned up by muting duplex scale in front of plate
termination, which unfortunately results in more loss of volume). I've had it
long enough to be certain about these things. The rest of the piano is
beautiful. Bass is incredible. Overall it's very musical. Harmonized very
well, and all voices are very clear and distinct. But the upper treble is
weak. Servicible, but definitely flawed. It's a shame. If I could fix, it
would have a world-class sound the whole length of scale.
But I'm just a duffer anyway. . .
George