On Tue, 2 Nov 2004 18:09:06 -0000, "Tim S Kemp"
wrote:

Stewart Pinkerton wrote:
Absolutely not the case. Given good implementations of all three, the
sound will be *identical*. BTW, it's more like 93-94 dB for properly
implemented 16-bit digital, because of that essential dither.

The problem with all this is you're saying 16, 24, 32 bit, 44, 48, 96, 192
khz will all sound the same.

For most people under most circumstances they will sound the same.

So 8 bit 44khz is fine too? or 12 bit?

8 bits is certainly not adequate; a properly implemented 12 bit system
wouldn't be too bad, but not really high quality. (The BBC used to use
a 13 bit 32KHz distribution system for FM radio and the quality was
often better than the alternatives available at the time.

Don't get me wrong, I'm not after a "my bits are better than your bits"
assault here, and much of the stuff I listen to is compressed (in both
senses of the word) anyway. But it is just damned wrong to say that the
difference between a 24/96 and a 16/44 recording is none at all.

There should certainly be a measurable difference, but it is pretty
doubtful that there will be an audible difference and if there was it
would be pretty small.

What we are trying to do is capture and store all the information that
the ear is capable of resolving. In terms of dynamic range it is
generally accepted that the range between the threshold of hearing at
the ears most sensitive frequencies and the threshold of pain is just
over 120db; his would be represented by a bit depth of 20. However,
ther are significant practical limts as well; there are very few rooms
with a low noise level. If you have a room with a noise level of 30 db
above the threshold of hearing you have a very quiet room. Also the
maximum output level available from commonly available speakers will
be about 110db in a room, if you're lucky. With these adjustments you
get a dynamic range of 80 db which can be adequately represented with
14 bit, so the 16 bits of the CD format has ample spare dynamic range.
Also, the threshold of hearing increases dramatically at higher
frequencies and not quite so dramatically at lower ones which means
that the dynamic range requirements at the frequency extremes are much
reduced.

The other capability of the ear is bandwidth. The highest audible
frequency is generally taken to be 20Khz, but it does vary between
individuals. If you're over 25 it's likely to be lower than that,
especially if you've spent any amount of time in clubs! If you're very
young it might exceed 20Khz by a small amount. A frequency of 20Khz
will be correctly reproduced with a 44Khz sampling rate, a 48Khz
sampling rate will be able to reproduce 24 Khz, which should
accommodate the most bat eared human.

Bill