Meridian America Digital Audio Processor Meridian 518 - Manual (Page 54)

Appendix 4 –Resolution Enhancement 54
518 User Guide
10Hz 100Hz 1kHz 10kHz
-20
0
20
40
60
80
100
d
B
s
p
l
SBM
Shape C
Shape D
Figure 6. Showing the effect on audibility of the 518's Shapes
C and D (C using pre-emphasis).
DAC enhancement by using high-frequency dither
The graphs above and in Appendix 1 (page 43) show that some of the
noise-shapers produce quite a lot of supersonic noise. This high level of
dither can have a very positive effect on DACs by causing them to
represent each level by averaging a large a number of different levels.
This high-frequency 'lubricant' tends to smooth out truncation and linearity
problems in real-world DACs.
Try the various shapes and see which one you like best in your system.
DAC or channel enhancement by word-length
matching
Digital systems work best if the input data is matched to the correct
wordsize for the device. Particularly where the signal has a larger
wordsize than the following device, then truncation distortion will arise.
The effects are real, but more subtle the other way round and are to do
with jitter and linearity.
In general 518 should be set to match the input and output wordlengths to
the incoming signal and following equipment. That will produce the
cleanest sound.