longitudinal mode vibrations

[Östen Häggmark]

Hello everyone,

>The steel a string is made of, is very dense, so I don't think you get
>mutch 
>longitudinal vibration there, or maybe only in very high frequencies.
>(>5000 Hz?)
>
>Jos.

In Harold Conklin's article in "Five lectures on the acoustics if the
piano" edited by Askenfelt, he defines longitudal modes of vibration
as:

"energy [propagating] lenghtwise along the string (as periodic
compressions of the string material) without sidewise (transverse)
motion of the string."

and also says:

"the lowest-frequency longitudal mode of a piano string is always more
than ten times the frequency of the lowest-frequency transverse mode"
(p 34)

The first longitudal mode normally occurs somewhere between the 12th
and the 20th partial, he reports.

Fig 32 on p 35 shows a spectrum of piano note E1 (41Hz) which displays
the first longitudal mode at about 600Hz, between the 14th and 15th
partial, and about 20 dB lower in level.

/Östen Häggmark
Stockholm, Sweden