Should I use an anti alias filter during resampling from l..

Archived from groups: rec.audio.pro (More info?)

Leonid Makarovsky <venom@csa2.bu.edu> wrote:
There exists 1 digital recording with a bit incorrect speed. I want to obtain
the correct speed. The speed is faster than it is supposed to be. I figured out
how faster it is so I reduced it. The way I did it was very simple. I set
the new sampling rate to 41987Hz (the original was 44100Hz). So I got the
correct speed 'cause the WAV file is stretched and music is played slower with
the right speed. Now I want to resample it to 44.1kHz to comply with the CD
specs. I do it in SoundForge and there's a checkbox Anti Alias filter. In help
file it says that I need to check this checkbox if I resample from higher
sampling rate to lower. In my case I resample from lower sampling rate to
higher. I tried both ways. The results seems to be different in a sense that
Exact Audio Copy report that the WAV files are different, but I don't hear
much difference. And even if I heard the difference I wouldn't know which one
is closer to the very original recording. I'd like to get an opinion from
experts here whether they suggest to use this Anti Alias filter or not. Thanks.

--Leonid

Archived from groups: rec.audio.pro (More info?)

In theory it should not be needed but also should not hurt anything if
used.

Mark

Archived from groups: rec.audio.pro (More info?)

Thanks.

--Leonid

Mark <makolber@yahoo.com> wrote:
: In theory it should not be needed but also should not hurt anything if
: used.

: Mark