Originally Posted by torii
Oh. Here is a simple video of a vinyl and CD test tone. Wonderful vinyl.
And another explanation of the vinyl shortcomings:
Richard D Pierce
In article <ajj8v..
- show quoted text -
It is based on the sampling theorem as developed by Claude
Shannon in 1948.
In short, it goes something like this. The amount of information
in any analog channel is proportional to the dynamic range of
the medium times the bandwidth of the medium. The dynamic range
is the ratio between the the maximum level encodable and the
lowest level that is unambiguously separable from the noise
In the case of the LP, the bandwidth is seldom, if ever, in
excess of 20 kHz, and often significantly less than that. Also,
in the case of LP, the dynamic range seldom reaches 75 dB, and
is pretty much physically limited to 80 dB at its theoretical
best, extremely rare counterexamples and claims notwithstanding.
The sampling theorem states that if one wants to perfectly
encode a channel whose bandwidth is f, one needs to sample at a
frequency of greater than 2f to perfectly capture ALL the
information contained within the bandwidth of f. And it also
states that to capture a dynamic range of R dB with a binary
representation, one needs a minimum of roughly R/6.02 bits.
Assuming correct implementation, that would indicate that a
quantized, sampled system with a sampling rate of 2*20 kHz or 40
kHz and a bit depth of 75dB/6.02 bits/db or 12.5 bits matches
the bandwidth and range requirements for high-quality LP
playback. Looking at it another way, considering 2-channel
playback, LP has an information rate of approximately 1
megabits/second. (40 kHz sample rate*2 channels*12.5
Redbook CD has a 44.1 kHz sample rate giving a bandwidth of 20
kHz or more, a 16 bit width giving a dynamic range of
approximate 96 dB, and two channels, resulting in an information
rate for the audio portion of 1.411 MBits/sec.
There will be those that argue, quite incorrectly, that the
sample rate and resolution of LP is "infinite" and thus the bit
rate is "infinite." These arguments are propped up on completely
cinorrect notions like "continuous" means the same as "infinite
resolution." The resolution in the time domain is a measure of
how often unique and unambiguous changes of state can occur, and
is DIRECTLY related to bandwidth. SImilarily, resolution in the
amplitude domain is a measure of how small a change can be
unabiguously encoded in the presence of noise, and is DIRECTLY
related to dynamic range.
Taken to its absurd logic end, "infinite resolution" in both
time and amplitude requires a system that exists for infinite
time and has available infinite energy and bandwidth. No such
system can evebn exist on a hypothetical basis.
None of the proponets of the "analog is infinite" 'theories' has
advanced a single credible argument to support their contention,
nor have they even shown the possibility of a flaw in the logic
of the sampling theorem.
And none of this suggest what system one person or another might
like to listen to. The specific technical question you posed
above regarding the nit rate, or more properly, the amount of
information in LPs. That technical question has a specific
technicla answer, and Claude Shannon, in his paper "A
Mathematical Theory of Communications," showed a definitive
means of calculating that answer.
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
And, in reality the Fourier Transform doesn't break down for a CD sampling and the wave is reproduced perfectly.
Good try though.
Nothing wrong with enjoying vinyl.
But to claim CD somehow removes anything is hogwash whereas vinyl clearly has a great deal of shortcomings.
And, on top of it all, you cannot hear everything there may be there to hear. For one, masking is real, you don't hear what is really masked by the ear/brain.