[net.audio] different quantization systems may be audibly different

markp@tekmdp.UUCP (Mark Paulin) (08/09/83)

It can be shown that for the ideal case the frequency response of a digital
audio system will extend to half the sampling frequency at the high end, and
that the S/N in dB will be very close to 10.8 + 6.0 * n where n is the number
of bits used in the quantization.

Thus the Soundstream system (sampled at 50kHz, 16 bit quantization) may be
expected to provide frequency response out to 25kHz with S/N of about 107dB.

The Denon PCM system (sampled at 44.2kHz, 14 bit quantization), on the other
hand, may be expected to provide frequency response out to 22.1kHz with
S/N of about 95dB.

The above comments are for the ideal transfer function.  In practice there
are several problems associated with real-time D-A conversion.  These problems
are more severe with the 16-bit system than with the 14-bit system.  I have
read that this is the reason for the use of the oversampled 14-bit technique
in the Magnavox player -- they do not believe that the 16-bit technology is
sufficient today to perform the D-A conversion in a MUSICALLY sound fashion.

I agree with the people at Magnavox, which is yet another reason for me to wait
for the next generation of players to hit the market...


Mark Paulin
...tektronix!tekmdp!markp