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Old 21-01-2010, 03:45 AM   #4
SumAnuT
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Join Date: Oct 2003
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Default Re: Audio Mythbusters

Evo da odgovorim sam sebi, iskopao sam knjigu od husnije kurtovica (da dokon sam sta cu ) u kojoj navodi da je rezolucija ljudskog sluha 1 dB, te da to odgovara promeni vazdusnog pritiska od 12%.

Isti podatak se navodi i ovde: http://www.tricell-ent.com/Oskar.htm

Quote:
Frequency variations verses amplitude variations: It is commonly accepted that the smallest change in amplitude that the ear can detect is 1 dB, which is a power difference of 26%. Compared to the ear's sensitivity to frequency variations of 0.06%. Contrasting to this relative insensitivity to amplitude changes with the ear's extreme sensitivity to frequency variations, it is difficult to understand the loudspeaker industry's obsession with the minor loudness variations of 1 or 2 dB in the frequency response of a loudspeaker, while completely ignoring the audible shifting or fluttering or high frequencies which can result from changes in membrane stiffness as a sound wave spreads transversely across a diaphragm.
Ove je izrazeno u akustickoj snazi pa je zato 26%, inace vrednosti se dakle podudaraju kao i tvrdenje.

Rezolucija konvertora je 0,0000012 Pa, dok je rezolucija ljudskog sluha 0.00002 x 12 / 100 = 0,0000024, dakle duplo veća, a ovo je 12% od praga cujnosti, da je zvuk stvara malo jaci pritisak, razlika bi bila astronomska, dok rezolucija konvertora ostaje ista.

Ako je to tacno, onda ispada da je rezolucija konvertora od duplo do mnogo veca nego rezolucija ljudskog uha, dakle ako se u signal unose sumovi koji su manji od rezolucije ljudskog uha, kako se onda to moze cuti?
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