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The ultra high-speed
sampling rate of 1-bit is crucial to achieve an ample dynamic range but
so is the 7th-order delta-sigma modulation 1-bit coding circuit's noise
shaping technology.
Figure 4 shows how a 1-bit signal stream is created by a very basic delta-sigma
modulation process. Through this process, inputted analogue signals are
converted into 1-bit signals consisting of continuous "0"s and "1"s.
Developing this process, SHARP has employed 7-th order delta-sigma modulation
(Figure 5). As can be seen in Figure 6, noise shaping at different orders
influences the amount of quantisation noise in the audible range. 7th-order
delta-sigma modulation minimises the greatest amount of quantisation noise
by shifting it to the higher frequency spectrum to ensure ample dynamic
range in the audible band.
Figure 7 shows 1-bit's and PCM multi-bit's reproduction ability of 10 kHz
square wave. This wave consists of a fundamental waveform and many harmonic
waves. While PCM multi-bit format cannot express the harmonic waves beyond
20 kHz, 1-bit's output is much more accurate to the original. In other words,
1-bit format is capable of capturing all the information including higher
order harmonic waves; a clear demonstration of 1-bit's ability to faithfully
reproduce all the sounds in nature.
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