Sound insulation but not thermal (what material?)

[dedeleco]

Obamot lacks the courage of his mistakes in addition to his silly insults absurd, refusing to read and understand the reality put before his eyes and repeated everywhere in books and on the internet, when he writes anything, in his insomnia at 3:22 am, like that, which he deleted afterwards, to recount yet a smaller error, realizing his c ... obstinate, stubborn and nervous:
Obamot had written, recorded by my computer:

aerialcastor wrote:

It makes a sound at 200Hz so if I'm not mistaken a Sol (pretty much).

... not quite, but I give you the answer as "good" since you flushed out the trick (you were just missing two zeros).

For a 20 Hz sound (first note organ pedal in very low sounds etc.) here is the correct calculation:

- if we have ƒ0 as the fundamental frequency at 20 Hz, the harmonics will have frequencies equal to: 2ƒ0, 3ƒ0 (the sound of 2ƒ0 becomes our "fundamental frequency"), and so on 4ƒ0, 5ƒ0, etc.

first harmonic 40 Hz
second harmonic 80 Hz
third harmonic 160 Hz
fourth harmonic 320 Hz
fifth 640 Hz haromonic
sixth harmonic 1280 Hz
seventh harmonic 2560 Hz
eighth harmonic 5120 Hz
ninth harmonic 10'240 Hz
tenth harmonic 20'480 Hz

Needless to say that the harmonics are multiples of the fundamental frequency (in general we take the "a3" at 440 Hz)

So a 20 Hz sound is propagated in the whole range of the audible spectrum audible by the human being (by a healthy person and endowed with an excellent leaf ...) and beyond in the ultrasound (therefore inaudible, which makes the response of Superform plausible, except that it went in the wrong direction ... theories of lower harmonics ... my paroie but he did it on purpose Mr. Green) From memory, because it must be in my first year course ...

This is essentially why the "law of mass" exists, so yes it is true that impact vibrations can dampen, but they are out of play, since the medium is not air. but the material (s) set in motion. It must also be recognized that impact noises are short and relatively infrequent compared to noise pollution transmitted by air (road traffic, aircraft noise, loud voices or the stereo set a little loud, TV, child crying / s or person playing a musical instrument, singing etc). It is therefore not admissible if we want to improve an existing sound insulation, since we cannot "redo the structure".

Mébon, it was Aérialcastor who found it. Low hat.

Dédé is miserably recalled in all these attempts and his dodges have demonstrated to perfection that he did not know what he was talking about - he who claims to be an expert above the rest - that is what it is when one is an eternal copier / paster who was probably so rebellious in class that he skipped lessons ... While he claims to be a "researcher".

Yes but in what? In crocodiles? Cheesy Grin Mr. Green

Admire his mistakes:
tenth harmonic 20'480 Hz
soit 20KHz,480 =20x2^10

Obamot after realizing the enormity of his salad in his stubborn brain corrected by:

... not quite, but I give you the answer as "good" since you flushed out the trick (you were just missing a multiple).

For a 20 Hz sound (first note organ pedal in very low sounds etc.) here is the correct calculation:

- if we have ƒ0 as the fundamental frequency at 20 Hz, the harmonics will have frequencies equal to: 2ƒ0, 3ƒ0 (but the sound of 2ƒ0 can also be found in turn as a "fundamental frequency", while the sound of 20 Hz continues also "its life" in multiples of its frequency), and so on 4ƒ0, 5ƒ0, etc.

Fundamental frequency 20 Hz
first harmonic 40 Hz
second harmonic 60 Hz
third harmonic 80 Hz
fourth harmonic 100 Hz
fifth 120 Hz haromonic
sixth harmonic 140 Hz
seventh harmonic 160 Hz
eighth harmonic 180 Hz
ninth harmonic 200 Hz
tenth harmonic 220 Hz

still wrong

because the use of all, in particular in mathematics in the Fourier series is to count the fundamental as harmonic 1, as the multitude of references in thousands of books and on the internet proves:
http://fr.wikipedia.org/wiki/Harmonique_%28musique%29
http://fr.wikipedia.org/wiki/Harmonique_%28musique%29
file: /// C: /Scarpbook-1/data/20120323040252/index.html
http://aboudet.chez-alice.fr/doc_musique/Timbre.html

The natural harmonics of a note are given by the multiple frequencies of the fundamental. Thus for a C at 32,7 Hz the harmonics are multiple of the fundamental frequency. For example, if the fundamental frequency is called "ƒ0", the harmonics will have frequencies equal to: 2ƒ0, 3ƒ0, 4ƒ0, 5ƒ0, etc. and the tenth harmonic is 10x32,7 = 327Hz passing from do 32,7Hz to close to mid 327Hz

Harmonic order number 1 2 3 4 5 6 7 8 9 10 11 12
Frequency in hertz 130 260 390 520 650 780 910 1040 1170 1300 1430 1560
Name of the corresponding note DO2 DO3 SOL3 DO4 MI4 SOL4 close to SIb4 D05 Ré5 MI5 close to FA # 5 SOL5

Obamot says anything, perishes, without ever reading or checking even the most elementary and shows very clearly that he knows absolutely nothing about this subject.

He does not deign to read even the pdf given by aerialcastor, simple, with everything that one should know without complications and where the law of mass is clearly indicated as a borderline case of material devoid of elasticity !!

I invite Obamot and also aerialcastor to answer my question assimilation test on this subject:

For Obamot, a question to think about:
The wall devoid of elasticity assumes what for the speed of sound: a zero or infinite speed ??
With very heavy, is it very rigid or very soft?

Indeed, when we really understood and assimilated, we can answer all the tricky questions and have 20/20 instead of 0/20 like Obamot.

Finally Obamot would do well to read the life of Fourier and to learn the bases of the famous series of Fourier which make it possible to calculate any periodic function of frequency f like sum of all the harmonics with nf with n = 1 with n infinite.
n = 1 is the fundamental and it is 1.f and not 0.f = 0 because otherwise the frequency 0, is not a periodic function of frequency f like those nf but a simple constant, equal to the mean value of the function over a period.
http://fr.wikipedia.org/wiki/S%C3%A9rie_de_Fourier
http://www.sciences.univ-nantes.fr/site ... rier1.html

of a level inaccessible to Obamot's small blocked brain and yet baba of physics essential if we want to understand a little the current technique !!
simpler in English:
http://en.wikipedia.org/wiki/Fourier_series

his life :
http://fr.wikipedia.org/wiki/Joseph_Fourier

Finally Obamot should read the links I gave instead of stubbornly making absurd errors:
aeriacastor's pdf
https://www.econologie.info/share/partag ... 3ew0Ml.pdf
course too difficult for Obamot who, with his stubborn and clogged little brain, will never understand why stacked and lighter layers are much better than tons of concrete, as all can see in noisy HLM concrete.

http://fr.wikipedia.org/wiki/Imp%C3%A9dance_acoustique

Finally he will understand better visually a vibrating rope that he can check by shaking a simple rope on:
http://fr.wikipedia.org/wiki/Harmonique_%28musique%29

[Obamot]

The first harmonic is the fundamental frequency, so in the example 20Hz. The tenth harmonic is fine at 200Hz.

It is well to "block" as much frequency as possible that we recommend using materials of different thicknesses for sound insulation. For example, asymmetric double glazing 10-4-6 or partitions with a BA13 and a BA18.

It's how we want, it doesn't change the problem.

The fact is that thinking about harmonics completely changes the data of the problem and it is not the "pad" from Dedelco who will change that ...

It's fun to see the pinnacle of his bad faith in falsifying a post in an attempt not to lose face. And especially not to recognize the error of his approach.

It is "sneaky revenge" and it speaks for itself ...

[dedeleco]

That changes everything, the Fourrier series derail, if f = 0 with the fundamental at frequency zero and all speak of harmonic 2 or double of the fundamental, he logically who is counted 1 !!

Obamot in his lazy and stubborn brain, by reading nothing, makes appalling salads !!

It's fun to see the pinnacle of stubborn, stubborn Obamot bad faith, falsifying a post to try not to lose face, in a first text, with the harmonic 10 of frequency multiplied by 2 to the power of 10 , error which shows that he understood nothing, nor assimilated the minimum necessary to understand !!


I think it speaks for itself, face reality written in thousands of books and very visible by shaking a simple rope !! ..

[Christophe]

Are we taking a break for the weekend?

[Obamot]

You're a little funny you and say it took you this long to react.

Only now you see that your theory of light heavy has sunk.



Pathetic your new skid.

[Christophe]

I was watching you from afar ...

Go 2 subject locked until ... when I want it!

[bidouille23]

You want it there, huh;)

[Obamot]

Yep, and whatever the frequency does not change the problem ... CQFD

Dedeleco cannot deny that the low frequencies propagate throughout the sound spectrum ... Despite his attempt to falsify to divert our attention, his theory of alternation of heavy / light materials cannot de facto block all frequencies as if by magic ...

... only manipulation and blah-blah-blah ...

[dedeleco]

And off we go stubborn !!!!

It's not not my theory but, that well established, known, of wave propagation, impedance adaptation, used even in the antennas of laptops in Obamot's pocket for microwave waves, presented in the courses and various links that I put, surrendered, surrendered, that Obamot, does not read, refuses to learn, he refuses to learn even the Fourier series, essential for understanding, that we cannot number any harmonics anyway, as it does for grains of sand, placed on a chessboard at the power of 10 on the tenth fret !!!!

For infrasound, at 10 to 20Hz, Obamot should ask the elephants, if their infrasound passes multiple walls like double or triple glazing !!
To emit these infrasounds, which we do not hear, it takes the great strength of the elephants (if not no emission), which hear them arrive the tsunamis to escape before !!

When Obamot deigns to read basic courses on the air, countless on the internet, as many as there are science faculties in the world ?????????????????

If this continues, I will put on econology dozens of pages of links to these courses, until Obamot, read one, makes the necessary effort very long for him and understands it !!


For the moment this hollow phrase from Obamot:

Dedeleco cannot deny that low frequencies propagate throughout the sound spectrum.

has no meaning or meaning !!!
A given low frequency like 20Hz remains at its frequency and does not propagate in the sound spectrum passing to 1 or 10 KHz, by magic !!!!

Obamot still did not understand anything, the harmonics obtained by plucking a vibrating string, neither the vibrating strings on piano or violin, nor the Fourier series.

[bidouille23]

I do not believe


it reminds me of tex avery, beep beep and the coyote, we press pause, the coyote takes a cup of tea with beep and when the break is removed zououuu it is off for a frantic race (I say bipbip and the coyote without any ulterior motive it is what came to me as an image).