Impressive Steinway Upright

Tony Caught caute@optusnet.com.au
Sun, 15 Sep 2002 13:49:20 +0930


Alan, Terry,

A soundboard should be totally under the influence of the strings. By saying
that I mean that any part of the soundboard that is not immediately and
directly influenced by the strings should be made dead.
This is done by putting cut-off bars across (usually the corner sections)
the soundboard to stop that section from vibrating with the strings.
As an example,
When the piano is played with the dampers off the strings, all the strings
are vibrating as is the soundboard. When the dampers re-engage the strings
the strings (hopefully) stop vibrating and so should the soundboard.
In a board with no cut-off or dumb bar, some sections, i.e. the corner
sections, carry on vibrating with rubbish sounds that linger on.
When played without using the damper pedal, these areas keep sounding the
vibrations of previous notes played thus muddling the sound that the
listener hears.
One of the major differences between uprights and grands is related to this
factor.

When you listen to a grand the sound is cleaner that in most uprights
because of this.  When you look at a grand soundboard you can see that the
rim of the piano virtually follows the shape of the bridge and the cut-off
bar cuts off the uncontrollable section of the soundboard in the bass corner
of the board. The cut-off bar can also be in line with the treble bridge to
also keep more balance to the board.

Were a soundboard "rimmed the same as a grand piano" that is in relation to
the bridges, then the upright would give the same output of sound as the
grand.

Regards


Tony Caught
caute@optusnet.com.au


----- Original Message -----
From: "Farrell" <mfarrel2@tampabay.rr.com>
To: "Alan R. Barnard" <mathstar@salemnet.com>; "Pianotech"
<pianotech@ptg.org>
Sent: Sunday, September 15, 2002 12:02 PM
Subject: Re: Impressive Steinway Upright


> A cut-off bar is a piece of wood, sometimes solid, sometimes laminated,
that, on a grand, has one end located about 1/4 to 1/2 the way down the
straight (bass) side of the rim, and the other end attached to the belly
rail perhaps a foot or more from the bass end. The cut-off bar is part of
the inner rim of the piano and effectively (or at least as it is designed)
terminates the soundboard at that point. The soundboard actually extends all
the way to the forward bass corner, but does not have an acoustic role -
that portion of the board is cosmetic. As a very broad generality, cheap,
small pianos do not have cut-off bars, better pianos often do. Del and/or
some others could explain the hows and whys of it, but all I am willing to
say here is that it helps the soundboard do its job better. A big laminated
bar is just that. Some cut-off bars are just a 1x2 or so solid piece of
lumber. I wonder how effective that is. I should think that if there is a
good reason to make a thick !
> massive rim, then there would also be some logic to making the cut-off bar
as massive as the rest of the rim (or at lest more than a 1x2). You can have
the same thing on an upright. Most I have seen on uprights have been a
smaller solid piece of hardwood. The one on this Steinway has quite a thick
cross section (I didn't measure it).
>
> That leads me to a question I have thought of many times. Rather than
putting a cut-off bar on a piano - my thoughts are usually of a grand - why
not just bend the darn rim where you would otherwise have the bar and have a
continuous rim run right into and be part of the top portion of the belly
rail. That way the inner rim would run from the high treble front corner of
the board, around the outside sides of the piano, and continue right across
the front of the board to the goofy belly-rail-soundboard-extendo-thingee
where there are no dampers (what on earth is that part of the belly rail
called - that little extendo box type jag in the belly rail?). That way the
rim would be one continuous bent & laminated chunk that would only be broken
by that high treble thingee (see last sentence). And actually, you could run
the inner rim that is part of the belly rail right to the high treble side
rim, but you just wouldn't want to attach the soundboard to it (you would
want to make i!
> t a tad shorter - so the box extendo thingee can do its job). We want to
make the belly one solid structure (as I understand it), and I have always
wondered why on earth pianos have a separate belly rail. What a great way to
weaken the whole assembly.
>
> While I am at it, why have wooden beams on the bottom of the inner rim.
Wouldn't an underbelly plate be just the ticket? No beams. No tension
resonator. Just a cast iron (or whatever) plate. It could run along the
entire belly rail and the inside side of the inner rim. Or maybe even a
combination of wood and metal - I guess the wooden beams are kinda nice for
nose bolt attachment points.
>
> I'm probably full of bologna here, but these are concerns of mine.
>
> That's all.
>
> Terry Farrell
>
> ----- Original Message -----
> From: "Alan R. Barnard" <mathstar@salemnet.com>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Saturday, September 14, 2002 5:23 PM
> Subject: Re: Impressive Steinway Upright
>
>
> > What, please, is "a big laminated cut-off bar?"
> >
> > Alan Barnard
> >
> > ----- Original Message -----
> > From: "Farrell" <mfarrel2@tampabay.rr.com>
> > To: <pianotech@ptg.org>
> > Sent: Saturday, September 14, 2002 2:27 PM
> > Subject: Impressive Steinway Upright
> >
> >
> > > I am the happy new owner of an 1892 Steinway 54" upright piano. It is
> > beautifully worn out and ready for remanufacture. It is impressive. It
has
> > full sostenuto and a full grand-style 2-inch thick bent hardwood rim for
the
> > soundboard and a big laminated cut-off bar. The plate extends to the
piano
> > bottom and has a couple-inch wide flange that bolts to the bottom of the
> > piano (the flange is 90 degrees to the plate). I haven't taken it apart
yet,
> > but I imagine it has the upper pinblock flange as well (my 1900 S&S
upright
> > has this).
> > >
> > > It won't happen tomorrow, but someday this will indeed be quite a
piano.
> > Anyone know what models have the bent rim? Why and when did Steinway
stop
> > using the bent rim. The only other bent rim I have ever seen on an
upright
> > was on a Bush & Lane.
> > >
> > > Terry Farrell
> > >
> > >
> > > _______________________________________________
> > > pianotech list info: https://www.moypiano.com/resources/#archives
> >
> > _______________________________________________
> > pianotech list info: https://www.moypiano.com/resources/#archives
>
> _______________________________________________
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