The Revenaugh Lower Lid in New York Times reply

[pianoman]

Hi Zen,
It seems like I remember that once sound waves bounce off of something like
a panel or inside a speaker box the phase is reversed and the waves will be
in phase again.  I think that this is how the bass reflex cabinet works. 
Actually sound coming from the top is a mixture of phasing.  The sound
straight from the soundboard going into the room and the sound bounced off
the underside of the lid out of phase. There is also the time delay effect
of this.   It would seem like a grand would sound better with no lid at
all, thence no phasing effects and no time delay..
Just my opinion.
James Grebe
R.P.T. from St. Louis
pianoman@inlink.com
"I am only as good as my last tuning"

----------
> From: Zen Reinhardt <diskladame@provide.net>
> To: pianotech@ptg.org
> Subject: Re: The Revenaugh Lower Lid in New York Times
> Date: Tuesday, December 09, 1997 7:25 PM
> 
> Anybody out there familiar with the physics of acoustics?
> 
> My dad (who has an undergraduate degree in physics) suspects that the
lower
> lid may give rise to some out-of-phase cancellation in certain
directions. 
> I'll try to look further into this with some other physicists I know ....
> 
> ZR!  RPT
> Ann Arbor  MI
> diskladame@provide.net
> 
> ----------
> > From: Delwin D Fandrich <pianobuilders@olynet.com>
> > To: pianotech@ptg.org
> > Subject: Re: The Revenaugh Lower Lid in New York Times
> > Date: Tuesday, December 09, 1997 2:02 AM
> > 
> > 
> > 
> > Benjamin Treuhaft wrote:
> > 
> > >      Today's NYT has a front-page story on a new invention: a lower
lid
> > > which collects and reflects outward the tone from the bottom of the
> > > soundboard - tone which normally just bounces around down there.  The
> > > only part of the idea I don't like is that with the lower lid in
place
> > > there is no room for me.  I love to sit under pianos when they're
being
> > > played.  You have to pretend you are checking the substructure or the
> > > customer will think you're nuts.
> > > Benjamin Treuhaft
> > > Berkeley, Calif.
> > 
> > -----------------------------
> > 
> > I looked up the story in the NYT and found it to be quite interesting.
> Especially the part that said Mr Revenaugh held the
> > patent on the device.
> > 
> > Odd. I'm sure I've came across an old patent on this idea before. As
in,
> from several decades back. Anyone living near a
> > library housing the proper reference works up to doing a quick patent
> search?
> > 
> > Personally, I'm not sure just how effective the device would be in a
> concert hall. I should think that if you were standing
> > close to the instrument on the treble side you might notice some
> difference. Back ten rows, I kind of doubt you'd hear much,
> > if any, change, let alone any improvement.
> > 
> > I should think, however, that this might be somewhat like positioning
the
> instrument, or deciding on voicing: shouldn't it
> > kind of be up to the musicians? The pianist and the conductor. Even,
> perhaps, the piano manufacturer. Surely it's not a
> > decision for the "artistic director" alone to make.
> > 
> > Del.
> > 
> >