"Jim Lesurf" wrote in message
...
In article , Iain Churches
wrote:

"David Looser" wrote in message
...

But a piano note is not a pure tone, it is rich in harmonics, and it's
well known that a very low note can be implied by creating the
harmonic structure that might relate to a missing sub-audible
fundamental, the human brain "filling in" the missing fundamental.
This trick is commonly employed in organs and is, I strongly suspect,
also how the Bosendorfer Grand Imperial appears to create a note of
16.45Hz.

Well actually it's simpler than that. It has an extra octave at the
bottom end:-)

Is it? I can't say. But having a key for such a nominal 'note' doesn't
establish that it produces an audible component at 16.45Hz.

The Bösendorfer piano to which I refer, the Imperial Grand Concert
piano, was specifically built at the request of Busoni sometime around
1900. The keyboard has a 97 keys, with keys of the extra
octave faced in black ebony. Some versions of the instrument have a
black hinged flap which can be closed to when the normnal 88 key
keyboad is sufficient.

One doesn't see these instruments often, and with a price tag of
Euro 200,000 not too many people have one at home.

As I'm sure you
are aware it has been a trick employed by organ builders to 'fake' very
low
frequencies by creating their harmonics. Causing human perception to
'hear'
the (absent) LF fundamental. Simplicity is sometimes easier to assume than
to carry out in practice. :-)

Yes indeed. Organ builders refer to this as pipe halving.


A quick calculation or a glance at Grove's chart will show
that the fundamental of C(0) is indeed 16.45Hz.

But as David had pointed out, each note on a piano does not produce just a
single sinusoid. So such a 'quick calculation' may not tell you what is
actually happening.

Can you point at some evidence to resolve this? I have no idea what occurs
in this specific case.

You may wish then to direct your question to:
http://www.boesendorfer.com/en/contact.html

Regards
Iain