> > I think this should be a seperate utility outside of lame? Most people
> > encode from CDs, which usually are already correctly filtered for stuff
> > below 20 Hz.
> >
> For pop music this is (mostly) true. I will test several CDs. Next week.
> The psycho part I would nevertheless filter with a 8rd order Chebychew
> high pass @80 Hz. Remember active controlled boxes by B&O. But also
> normal vented tubes have a relatively sharp cut off at low frequencies,
> so don't rely on masking.
>
The windowed FFT used for the psycho acoustics surely has better
frequency responce than an 8th order Chebychev filter,
so there will negligable leakage of this 80Hz tone into
other frequencies. If you think this is a problem, I would
try some experiemnts by removing (from the psycho acoustics)
the coefficients up to 80hz.
Mark
--
MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
