[vdr] Low volume on Pro7 ?

Prakash Punnoor prakashp at arcor.de
Mon Jun 13 16:08:47 CEST 2005


Dr. Werner Fink schrieb:
> On Sat, Jun 11, 2005 at 01:17:11PM +0200, Prakash Punnoor wrote:
> 
>>Dr. Werner Fink schrieb:
>>
>>>On Sat, Jun 11, 2005 at 12:21:26PM +0200, Prakash Punnoor wrote:
>>>
>>>
>>>>>We already had this disussion with "CD" and the "giant" 90dB
>>>>>they claimed to give.
>>>>
>>>>IIRC, CD gives something like 114db with dithering...and 96db without.
>>>
>>>
>>>Informations which are not recorded can not be recreated without guesssing.
>>>Therefore 16 bits are 96db and not more.
>>
>>Nope, you obviously don't know how dithering works. Every heard of DSD? So you
>>think Sony's SACD doesn't work? DSD is pure dithering...
> 
> 
> -> http://www.hfm-detmold.de/eti/projekte/diplomarbeiten/2004/dsdpcm/23.htm

But what do you want to tell me? You are right or me? I am not an audio
expert, but if I may quote following, I think it rather backs me up, as AFAIk
noise shaping is a form of dithering, too. I understand:

96kHz, 20 bit pcm ~ SACD ~ 96kHz, 16 bit pcm w/ noise shaping

So dithering does help to reduce noise levels. Or did I completely
misunderstand anything?

I am not suggesting to add dither later to a signal, but if you have a 20bit
source and dither down to 16bit, you will have a better signal than 16 bit
truncated/rounded - which was my original claim.

"
Von den DVD-A-Befürwortern wird die SACD mit ihrer Bandbreite und Dynamik
oftmals mit einer DVD-A von 20 Bit und 96 kHz Samplingfrequenz verglichen,
welche jedoch den geringen Noise-Floor über die gesamte Bandbreite bis 48 kHz
beibehalten kann. Gerne wird darüber hinaus betont, dass auch bei der DVD-A
aufnahmeseitig Noise Shaping verwendet werden und somit bei einer
Quantisierung von nur 16 Bit der Rauschpegel der SACD (bei einem deutlich
geringeren Gesamtrauschpegel) mühelos unterboten werden kann.
"

-- 
Prakash Punnoor

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