naturerecordists
[Top] [All Lists]

Re: Hello and a Sony PCM D100 question

Subject: Re: Hello and a Sony PCM D100 question
From: madl74
Date: Sun Jun 22, 2014 9:31 am ((PDT))
>  REC LEVEL 3 (clipping level : -9 dBu),
>  S/N100 off: noise floor: -105 dBu(A), dynamic range: 99dB
>  S/N100 on: noise floor: -116 dBu(A), dynamic range: 107dB

Raimund, 

What did the noise floor consist of? Is this level the added dither? You can 
get total silence below 15 bits +1 without dither but the quantising noise 
is then bad. The output is a 16 bit uncompressed file, even if 18 bits were 
used in quantising it, so what is the effective final dither level? 108dBs 
is a dynamic range of 18 bits and with a parity bit, this is 19 bit A to D. 

Are the Sony figures about adding two bits worth of dynamic range taking 
dither into account, or is this an engineering exercise in numbers? I can't 
see how you can get 18 bits into a 16 bit WAV pint pot. The dynamic range 
from 1 bit (square wave) to 15 bits digital is 84dBs. 

If you or anyone has a WAV file of "silence" on the two settings it may be 
interesting to compare them. 

David Brinicombe 








<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU