> On 01/10/2022 1:37 PM vicki melchior <[email protected]> wrote:
> 
> 
> Okay. In the context of subtractive dither, I understand the confusion.

I don't.  I'm just confused.

> Yes, the purpose of subtractive dither is to reduce the total dither noise 
> remaining in the output, typically after adding dither during bit reduction. 
> Clearly, that will increase the SNR

But only by 4.77 dB.  But, hey, it's 4.77 dB.  So if they can standardize how 
the dither is generated from the LSBs of the quantized signal, and, if noise 
shaping is done, what the transfer function is from dither to quantized output, 
then why not do this subtractive dither thing?

The worst that can happen is that the receiver does not decode those LSBs and 
subtract the dither.  Then you're no worse off than if it was just additive 
dither and you don't recover those 4.77 dB SNR.

> and allow you to hear more of the signal.

only really makes a difference if the audio is living down by the noise floor 
(which it could be if it's a CD and classical or uncompressed acoustic music 
with a large dynamic range).

but 4.77 dB is 4.77 dB.  that's something.  96 dB dynamic range is better than 
91 dB.

--

r b-j . _ . _ . _ . _ [email protected]

"Imagination is more important than knowledge."

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