Question about picture graph of 42 Hz bass note

[waynep]

I hope it’s okay to post this here – I couldn’t find a specific sub-form that seemed to fit my question.

I recently was involved in a discussion on another Forum about overtones and harmonics, where I was trying to argu that they extend below the fundamental as well as above, so I was tickled to see this picture from this page of this Forum:





What I’m trying to figure out is, the text that goes with the picture says it’s the frequency response of a 42 Hz note from a bass guitar. I would logically assume that the circle represents the fundamental being discussed, yet looking at the markings at the bottom of the picture, it looks like it’s just above 55 Hz.

So - Is the fundamental actually where the circle is, or is it actually the tall spike below the circle, and the graph is mis-marked?

[ThomasW]

Can't tell you anything more than I found in posted on a forum years ago with a label that it was the low string from an electric bass.

42Hz would be the spike to the left of the circle. More realistically the text states it's ~84Hz, that corresponds with the highest spike.

[chrisbee]

Percussive effects can probably go down to DC.

No matter how gently a string is plucked, or even touched, there is a starting transient from first contact long before the string finds its own voice.

The body of an instrument can also produce its own range of tones.

[waynep]

Here's the text accompanying the picture, cut and pasted from the above link:

To illustrate this point, below is the frequency response from the "E" string (42Hz) from a electric bass guitar. One can clearly see how high in frequency the harmonics go compared to the 42Hz fundamental.

Still, it makes sense that the picture is really of an 84 Hz note, since that's the highest peak shown.

[mfine]

No that is highly flawed logic. It looks like a 42 hz fundamental. The one octave up harmonic is usually pretty strong in string instruments and depending on the instrument pluck electronics etc, the harmonics can be significantly louder then the fundamental. Timing also matters as the decay will vary.