Flawn,
Thanks! Very good stuff! As an "analog" I get confused all the time!
And the "digital" people don't seem to know about "older analog times".
Got more like this?
Klas
At 16:48 2012-07-22, you wrote:
>Watch for confusion in terminology here:
>
>In older analog times, "signal to noise ratio" referred to the
>difference between the noise floor and the average program signal (0
>on a real mechanical VU meter with standardized ballistics). It was
>presumed that there would be additional range called "headroom"
>above the average program level for louder peaks. S/N + headroom was
>referred to as Dynamic Range.
>
>In the digital world, the terms "signal to noise ratio" and "dynamic
>range" are often used interchangeably, with confusing results. When
>a noise spec is listed in a digital system, it's typically relating
>the noise floor to the maximum peak value of 0 dBFS (aka "full
>scale"). Makes the numbers bigger...makes the ad writers happier.
>There is no headroom above full scale (leaving aside floating point system=
s).
>
>Average program level in a digital system is variously defined by
>different devices as anywhere from -20 dBFS to -12 dBFS. So if you
>choose -20 dBFS as your target for average program level, then your
>-138 dB noise spec/dynamic range translates into 118 dB of signal to
>noise ratio plus 20 dB of headroom. Insert picture of glum ad writer here.
>
>--Flawn
>
>
>On Jul 22, 2012, at 1:23 AM, wrote:
>
> > 1b. Re: artifact in spectrogram analysis
> > Posted by: "sainganrob" sainganrob
> > Date: Sat Jul 21, 2012 1:22 pm ((PDT))
> >
> >
> >
> > --- In "Avocet" <> wrote:
> >>
> >
> >> I haven't looked at 24 bit recordings on my affordable Tascams, but I
> >> suspect that the least bits are noisy. For a start, no analogue input
> >> is likely to have a signal to noise ratio of 138dB if only because
> >> that takes it beyond thermal noise.
> >>
> >
> > Not quite, remember, signals go above reference levels as well as below=
:)
> >
> > A 150R, 20KHz BW, 20 degC source at a nominal 'Line Level' peak
> of +8dB re (0.775) is 139dB SNR.
> >
> > A typical clip point for a Line Input stage is +20dB and so would
> equate to a 151dB SNR.
>
>
>
>------------------------------------
>
>"While a picture is worth a thousand words, a
>sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.
>
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>
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