# Info on soundwaves and overtones

1. Jan 1, 2009

### djef

hallo all,

while reading some info on soundwaves and overtones I found the following statement on wikipedia:
"The first overtone is the first allowed harmonic above the fundamental frequency (F1).

In the case of a system with two different ends (as in the case of a tube open at one end), the closed end is a node and the open end is an antinode. The first resonant frequency has only a quarter of a wave in the tube. This means that the first harmonic is characterized by a wavelength four times the length of the tube."

now I want to know why it is like this:
The first resonant frequency has only a quarter of a wave in the tube. This means that the first harmonic is characterized by a wavelength four times the length of the tube.

Why the 4 ?

how do they get that?

2. Jan 1, 2009

### tiny-tim

happy new year!

Hallo djef!

The wave has to go up , come back, go down , and come back, to do one wavelength.

For a tube closed at one end, the wave only has time to go up â€¦

that's 1/4 of the wavelength.

3. Jan 2, 2009

### djef

Re: overtones

oh yes, indeed, thanks a lot tiny-tim