Thursday, December 03, 2009

Vinyl bit depth

MW = g/mole

polyvinyl chloride = H3C2Cl
density = 1.39 g/cm3

H=1, C=12, Cl=35 = MW 3+24+35 = 62

mole = 1.39g/62 = 0.0224

Avogrados number = 6.022 x 10^23

molecules per cm3 = 0.0224 * 6.022 = 13.49 * 10^21
cube root of 13.49 * 10^21 = 2.3804 * 10^7 or 23,804,000

23,804,000 < 24777216

therefore 24 bit audio is better than vinyl.

is 16 bit audio better than vinyl too?

only if the error margin in printing vinyl is greater than around 256 molecules... how likely is that?

2 comments:

Duncan said...

But the much higher sampling rate (~23 MHz? depending on how you count it) allows all sorts of sub-sampling effects to happen, significantly increasing the fidelity of the output...

Richard Fabian said...

the sampling rate would be down to how fast the needle can move without requiring damaging pressure on teh vinyl. I can't figure out a sensible way to calculate that value. But, yes, obviously there's going to a much higher quality reproduction on excessively high pitch noises.
So analog would can be just as high quality as digital. Which we know, but it doesn't denigrate digital for storing human audible recordings as the human ear can't really do better than 20khz.