--- Farrell <mfarrel2@tampabay.rr.com> wrote:
> "Some pianos ( Boesendorfer, old Chickerings,
> Emersons, etc. ) use spruce for case and beams, so
> that some of the energy transmitted to them will
> still be converted to audible resonance."
>
> Are you saying that a Bosendorfer outer rim produces
> audible sound?
You bet! Designed to. Knock on one someday!
>
> "Spruce, while light, is still considered a
> "hardwood" as the fibers between the rfesonant
> vacuous cells are tightly compacted."
>
> Who or what industry considers spruce to be a
> hardwood? There are indeed soft hardwoods and hard
> softwoods, but spruce is a soft softwood. There is
> nothing hardwood about it.
I disagree. Though obviously not a " hard hardwood ",
unlike most other conifers, I have heard lumbermen
call it a hardwood. Stumped me too. ( Pun intended )
Sitka spruce is stiffer and more brittle. Maybe that's
why.
>
> "On many old pianos the cases were also veneered
> with rosewood or ebony. This was not just cosmetic,
> as these very dense woods transmited vibrations
> around the case..."
>
> Even veneers are transmitting? How have you come to
> this conclusion?
Well, gee, they make xylophone bars out of rosewood.
Its simple. The denser a material is, the better
vibrations travel thgrough it and are not converted to
heat. Simple physics law. The Victorian makers were
VERY attentive to detail ( as you have mentioned in
previous posts and anyone can see by dissecting one of
their pianos ). And I have read this as intentional
usage in period literature ( AS&W transcripts, if I
remember. ) And although I find hide glue noxious, it
has excellent density and transmittal characteristics
( one resaon why it is preferred by Luthiers ) and in
combination with a dense veneer will not cause as much
energy to be lost as heat as, say , luan mahogany.
Respectfully,
Gordon Stelter
>
> Terry Farrell
>
> ----- Original Message -----
> From: "gordon stelter" <lclgcnp@yahoo.com>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Monday, September 16, 2002 4:56 AM
> Subject: Re: Piano Sound: was something else
>
>
> > Well, it WILL reflect some vibration back,
> regardless.
> > The stiffer, denser, and more rigid the rim is,
> the
> > more vibrations will be relected back into the
> board.
> > What is not reflected will be tranmitted to the
> > case/rim, and either carried back to the board
> > somewhere else or dissipated as heat in the rim
> wood
> > fibers. I think it is optimal that this vibration
> be
> > dissipated by heat in the lampshades and curtains
> of
> > the room the piano sits in, not the piano itself.
> In
> > other words, as much of the pianist's finger
> pressure
> > as possible should be converted to sound and LEAVE
> the
> > piano, before being absorbed by soft materials. I
> > believe the softer case woods in many modern
> pianos,
> > Asian or otherwise, largely contributes to their
> > relatively impotent tone when compared to high
> quality
> > pianos from 100 years ago!!!
> > That said, the relationship between stiffness
> and
> > density will play a vital role in the piano's
> tonal
> > "personality". Some pianos ( Boesendorfer, old
> > Chickerings, Emersons, etc. ) use spruce for case
> and
> > beams, so that some of the energy transmitted to
> them
> > will still be converted to audible resonance.
> Spruce,
> > while light, is still considered a "hardwood" as
> the
> > fibers between the rfesonant vacuous cells are
> tightly
> > compacted. So it has both high transmittal and
> > resonant properties. But not the best reflective
> > properties when used in a case application, as it
> is
> > not dense enough, overall, to make extremely rigid
> > structures.
> > At the other extreme are old Knabes, which
> have
> > the most "rock hard" rims (and cases) I have ever
> > seen! In these pianos a fast, loud, rather hard
> tone
> > is emitted, as vibrations are quickly kicked back
> to
> > the board, which is held very rigidly by massive
> rock
> > maple cases. I have seen many 100 year old Knabes
> > with excellent crown. It should also be noted
> that
> > these boards have a heavy coat of finish, usually
> > shellac, which is extremely stiff ( and brittle )
> when
> > fully cured. This brittleness surely aids
> vibrations
> > as they travel across the face of the board. ( But
> I
> > use 2 part "conversion" varnish, as it also has
> this
> > property but is more impervious to humidity, and
> is
> > inedible to the house crickets that live here.
> "Down
> > side" is that it emits formaldehyde fumes like
> crazy
> > for several months as it cures. )
> > On many old pianos the cases were also
> veneered
> > with rosewood or ebony. This was not just
> cosmetic, as
> > these very dense woods transmited vibrations
> around
> > the case to where they could be re-absorbed by the
> > board. The builders new this.
> > Gordon Stelter
> >
> > --- Tony Caught <caute@optusnet.com.au> wrote:
> > > So you says that a rim reflects or has to
> reflect
> > > ?. And why should it. ?
> > >
> > > Tony Caught
> > > caute@optusnet.com.au
> > >
> > >
> > > ----- Original Message -----
> > > From: "Richard Brekne"
> <Richard.Brekne@grieg.uib.no>
> > > To: "Pianotech" <pianotech@ptg.org>
> > > Sent: Monday, September 16, 2002 5:13 PM
> > > Subject: Piano Sound: was something else
> > >
> > >
> > > > We keep ridiculing this, without really
> knowing
> > > what it refers too.
> > > Similiar subjects come up and get discounted
> more or
> > > less out of hand also.
> > > Yet much is made of the importance of string /
> > > soundboard impedance match to
> > > sustain and power. Perhaps there are other
> > > "impedance matches" to the
> > > strings energy that play an important /
> significant
> > > roll in the "end
> > > product" sound of the piano. Perhaps its not so
> much
> > > a matter of whether one
> > > rim reflects more or better then another... but
> > > rather that one rim
> > > relfects an optimal amount.. ??
> > > >
> > > > RicB
> > > >
> > > > Farrell wrote:
> > > >
> > > > > This is what I am describing on the S&S
> upright.
> > > And are you speaking in
> > > reference to the "magic circle of sound"? Does a
> > > laminated rim "reflect"
> > > sound better than a solid timber frame?
> > > > >
> > > > > Terry Farrell
> > > > >
> > >
> > >
> > > _______________________________________________
> > > pianotech list info:
> > https://www.moypiano.com/resources/#archives
> >
> >
> > __________________________________________________
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> >
>
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