So are these "rubbish sounds" just specific,
sympathetic resonances picked up by the spruce in
areas where he daming of the strings would not supress
them ( corners?)? That's what I have always thought
the "cutoff bars" were for: to dampen soundboard areas
prone to this effect. Bush and Lane(and a few others)
made uprights with an actual curved, laminated "inner
rim" which I believe acted as "cutoff bar" as well as
sending the vibrations around the board and reflecting
them back into it, like a grand rim would.
Gordon Stelter
--- Tony Caught <caute@optusnet.com.au> wrote:
> >
>
> > A few comments and questions interspersed below:
> >
> > Terry Farrell
> >
> > ----- Original Message -----
> > From: "Tony Caught" <caute@optusnet.com.au>
> > To: "Pianotech" <pianotech@ptg.org>
> > Sent: Sunday, September 15, 2002 12:19 AM
> > Subject: Re: Impressive Steinway Upright
> >
> >
> > > 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.
> >
> > So, doesn't that mean that soundboard area is
> under the influence of the
> strings?
>
> Yes, when cutoff bars are fitted.
> >
> > > 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.
> >
> > Really? Is this a way to increase sustain?
> "Rubbish sounds": is that kinda
> like many duplex scales?
>
> No, it does not increase sustain, sustain is how
> long the strings ring. I am
> talking about when the dampers reengage the strings
> to stop them vibrating,
> the soundboard should also stop vibrating. Which it
> does.
> Except for those areas not under direct control of
> the strings. These areas
> still vibrate at random frequencies for a short
> time.
> Rubish sounds are kinda like a composite of all the
> strings ringing at one
> time, in reduced form of course, Duplex scales /
> sounds are generally of the
> higher frequencies, these left over sounds are
> generally of lower
> frequencies. Think of a wopple board sound.
> >
> > > 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.
> >
> > I don't understand. How do uprights and grands
> differ in this respect?
>
> Please reread "When you look at a grand soundboard
> you can see ......
>
> >
> > > When you listen to a grand the sound is cleaner
> that in most uprights
> > > because of this.
> >
> > Like a Yamaha? Some folks criticise this type of
> sound.
>
> No. I think the Yamaha clean sound that you may be
> refering to is the one
> caused by thicker soundboards, greater tension on
> the strings and harder
> hammers.
> The clean sound that I am refering to is, when a
> note is played and stopped
> there is no sound. When a series of notes are played
> and stopped, the notes
> do not run in together. Dampers may be perfect but
> still in some pianos you
> get the effect that the dampers are not working as
> they should. They are,
> but some areas of the soundboard are still producing
> audible sound.
> >
> > > 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.
> >
> > Makes sense.
> >
> > > 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.
> >
> > Specifically, what do you mean here? How does a
> grand rim necessarily
> differ from an upright rim? Are you speaking of the
> most common modern grand
> rim that is laminated vs. the most common upright
> rim that is solid
> timbers - or at least straight pieces of wood? Why
> would that make a
> difference? I have an Everett grand in my shop with
> a solid-timber rim - and
> the S&S upright with the laminated rim. But what
> would make one necessarily
> sound better/different than the other.
> >
> I am referring not to the rims construction but to
> the location of the edge
> of the soundboard in relation to the bridges.
> Naturally the rim is important
> to be solid but that is another tonal issue relating
> to the soundboard but
> not this one.
> Cost is the deciding factor in upright pianos. It is
> easier to not have any
> cutoff bars (cheap pianos) Next a straight cutoff
> bar at the top left hand
> side corner (medium price pianos) Next a shaped
> cutoff bar at the top left
> hand side corner with a shaped cutoff bar between
> the treble and bass
> bridges. (expensive pianos, mainly old expensive
> pianos. Next ask Del, he
> may let go with some super secret shape that he has
> in his mind that hasn't
> been fully developed yet.
>
> Actually the S&S upright that you have with the
> laminated rim may be the
> last one I described.
>
>
> Regards
>
> Tony Caught
> caute@optusnet.com.au
>
>
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