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DSD is 1bit PWM Sigma Delta audio format.In PCM that dont have dithering,silence looks like samples with 0 value,I wonder,what does DSD silence looks like.Is it just series of 0 value samples,or does it switch between 0 and 1 constantly,third option,it changes between 0 and 1,but not constantly,more in noisy random way.

Many DACs these days use are multibit sigma delta,how does multibit sigma delta silence looks like?

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  • $\begingroup$ It's a delta sigma at 2.8Mhz sample rate at 1 bit per sample . The data can dither a pattern by 0 bias null? $\endgroup$ Commented Jan 10 at 17:26
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    $\begingroup$ Silence looks a lot like random toggling between $-1$ and $+1$ in a manner that looks like the DSD bit stream for any other signal. It's just that, because of noise shaping, the amplitude of the frequency content below 20 or 22 kHz will be close to zero. There will be all sorts of energy above 22 to 24 kHz, but since we don't hear that, it sounds like silence. $\endgroup$ Commented Jan 10 at 19:27

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DSD bits are 0 and 1 indeed, but they actually represent normalized outputs of -1 and 1, respectively, since one-bit samples can only be mid-raiser-quantized. This means DSD samples cannot represent zero. One can generate DSD silence by alternating 0-s and 1-s (your second option), or by a 1-bit delta-sigma modulation of a zero PCM input, with or without dithering (your third option). Multi-bit modulators can (and normally use) mid-tread quantization, so they can represent zero. Thus, multibit silence is either a sequence of zeroes or the output of a multi-bit delta-sigma modulator presented with a zero input.

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  • $\begingroup$ I dont understand your last sentence.Its either "sequence of zeroes",ok,I understand that,"or the output of a multi-bit delta-sigma modulator presented with a zero input" I have no idea what this means. $\endgroup$
    – Sweeper
    Commented Jul 23, 2018 at 15:32

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