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Old Aug 8th 2014, 06:23 AM   #1
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Fundamental frequency of guitar string vs fundamental note of sound

how to solve this? the ans is 352, 704 and 1056hz i have no idea. can someone help ? thanks!
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Old Aug 8th 2014, 09:55 AM   #2
MBW
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1/4 length of string gives 4* frequency

the string is divided into two portions,
the longer bit is 3 times longer than the short bit.
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Old Aug 8th 2014, 07:51 PM   #3
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Originally Posted by MBW View Post
1/4 length of string gives 4* frequency

the string is divided into two portions,
the longer bit is 3 times longer than the short bit.
why the fundamental frequency of note isnt equal to fundamental frequncy of string?
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Old Dec 21st 2015, 03:58 PM   #4
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Fundamental ? frequencies.

You have posed a tough one here. Remember first of all that we don't actually hear sound at all. That which our Brain registers is the result of a mysterious computation which takes place in a very mysterious process.

It is usual to take (mathematically) an octave to be a doulbling of frequency. I had a collaegue who got roped into a scheme to build an electronic organ for their church. The construction work finished he borrowed a load of equipment from the laboratory and spent the weekend meticulously setting-up the whole legion of oscillators. Then they called in the organist!

On Monday morning he reported to me that: "It sounded b**** awful!"

He had set his oscillators on a linear scale whereas in Nature everything works on logarithmic scales; i.e. each note is related to the last, not by a fixed interval, but by a percentage of the last.

Think about it and you should discover why it takes constant practice to play a vio!. It also explains the extreme difficulty of independent navigation in Space.

In Nature, no matter the discipline, everything operates on log scales.

Talk to a piano tuner and ask why he does not use an electronic tuner instead of constantly bashing keys together so making a most boring noise. The instrument does not have to BE right - it has to SOUND right. I stand to be corrected but I believe Mozart championed the "even-tempered scale" which enabled construction of the modern piano and such things as the pipe organ.

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Old Dec 22nd 2015, 08:53 AM   #5
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The question is ambiguous. 1/4 th from which end? The bridge or the nut? If we assume from the nut end, then it is the remaining length of the string that is 3/4 L (L is the original length ) which is responsible for the frequency generated . Thus 3/4 L corresponds to lambda/2 as the string is now clamped at two ends, the fret and the bridge. Thus lambda corresponds to 2 x (3/4) L or 3/2 L. Since the wave speed in the string is the same say v, v = f1 x lambda1 = f2 x lambda 2.
Now L = lambda / 2, or lambda = 2L for the frequency of 264
Thus,
264 x 2L = f2 x (3/2) L. Thus f2 = (264 x 2 x 2) / 3 which gives you the required answer of 352 Hz. The next overtone will correspond to half the current length or twice the current frequency. The one after will correspond to 1 / 3 of the current length or thrice the current frequency, giving you the required 705 and 1056 Hz.
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Old Dec 25th 2015, 07:23 PM   #6
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Frequency of string instrument.

As a follow up on my last post y ou might consider making measurements on a viol. It appears to produce wavelengths which it cannot support physically.

In his later years it was said that Sir Henry Wood lost much of his high-frequency hearing and yet he was known to tick-off one of his violinists for being a fraction of a tone flat!

I believe that the snswer to this perplexity lies in the fact that, similar to seeing, we do not hear anything directly. It is a matter of serious computations in the Brain honed over many generations by the urge to survive.

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