But that is 32767:1 not to 32767:0 (which is infinite!)

96dB is the SNR: 32767:0.5

Victor
----- Original Message ----- 
From: "Federico Vanni" 
To: 
Sent: Sunday, December 21, 2008 8:49 PM
Subject: [Csnd] Re: Re: Re: Re: dynamic range


>
> with ....ZERO i mean simply 32767 and nothing.
> that is, again, 20*log10 32767.
>
> fv
>
>
> Il giorno 21/dic/08, alle ore 19:55, jpff@cs.bath.ac.uk ha scritto:
>
>>> jpff@cs.bath.ac.uk wrote:
>>>
>>> 90 dB, instead, is the ratio between ZERO and the largest possible
>>> value,
>>> that is 20*log10 32767.
>>
>>
>> Come on!  The ratio between zero and any strinctly positive number is
>> infinite
>>
>>
>>
>>
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>
>
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[coming late to this thread]

I have tended to assume people cite 96dB somewhat casually, based on 1 
bit (doubling of level) = 6dB, so 16bits = 96dB. It is a convenient 
approximation.


With dithering, you can get a dynamic range greater  than 96dB, I forget 
the details. I am rarely in a position to to turn the amp up loud enough 
to notice.

NB: previous to implementing 0dbfs, I wrote the ampdbfs and dbfsamp 
opcodes to enable decibel levels to be written in accordance with 
industry practice (i.e. digital peak = 0dB), even when using the archaic 
  quasi-16bit amplitude model. But as noted elsewhere, setting 0dbfs=1 
is by far the best approach these days.


The logic is very simple - digital peak equates to maximum level 
regardless of sample resolution - if you then define a signal at -110dB 
  you will lose it if rendering to a 16bit file, but retain it (audibly 
or not) if rendering to 24bit or better.  In other words, there is a 
fixed ceiling, but a moveable floor - you can define sounds as quietly 
as you like (e.g. envelope tails), in a predictable way,and  preserve 
them or not (without changing the orch code at all), depending on the 
resolution (file or audio i.o) you render to.


Richard Dobson