"David Looser" wrote in message
...
"Iain Churches" wrote in message
...

"David" wrote in message
...
"David Looser" wrote in message
You are correct on all counts. The only acoustic instrument capable of
creating these sorts of levels at sub-audible frequencies is the pipe
organ.

Oranges are not the only fruit.

The orchestral 60" bass-drum (Turkish or Italian Gran cassa)
and contrabass sarusaphone are also close contenders (not as
oranges, but as producers of sounds that are "less like notes and
more like sensations":-)

The Bosendorfer Grand Imperial concert piano is also pretty
impressive in its ability to make the earth (and even the orange) move
with C(0) at 16.45 Hz.


The human ear is extremly insensitive at frequencies below 20Hz, indeed
these very low frequencies are felt, more than heard. However it takes
considerable power to create a sound wave powerful enough to be felt in
this way. It's easy with an organ, just build a bloody great pipe and blow
a lot of air through it. However with a piano the only source of power is
the pianist's finger, and that's not going to be powerful enough.

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


Iain