On Wed, 8 Sep 1999, Robert Hegemann wrote:
> Mark wrote:
> > The energy of this wave shows up in scalefactor band (sfb) = 12,
> > with an energy of -10db. The dynamic range of a CD is 96db,
> > meaning that the energy range in sfb=12 is: -106 -> -10 (db).
>
> This is true for L/R channels. But, what would the situation be
> in MS stereo? As with M=(L+R)/sqrt2 and S=(L-R)/sqrt2
> the dynamic range for the mid channel M would go up
> to (96+96)/sqrt2 = 136 db and for the side channel S down
> to (96-0 )/sqrt2 = 68 db. So we have to consider this computing
> the ATH.
>
> Robert
>
It isn't quite that bad. db = 10*log(Energy), where Energy = square
of the MDCT coefficients. If you work this out, you can see that
the energy in the mid channel is at most twice the energy in the left
or right channel, which is 3db.
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