🚀 go-pugleaf

<tigerdog@adobeforums.com> wrote in message 
news:59b82102.-1@webcrossing.la2eafNXanI...

>I use Audition mostly to create digital archives of vinyl LPs. While I have 
>a very good turntable, preamp and cartridge, there is still enough residual 
>low-frequency information (25Hz and below) that I would like to eliminate 
>it. I do NOT want to lose what LF info is present, only eliminate the 
>residual rumble. I understand there are several ways of going about this in 
>Audition:

> - equalizer / parametric equalizer reducing low frequencies

Best tool for general LF noise  is probably one of the scientific high-pass 
filters.

If there is a discrete LF tone then the DTMF filters are the better choice.

> - noise reduction, getting noise profile from silent passage (lead-out 
> groove)

Low frequency noise from LPs does not seem to always have the necessary 
properties for this to work well.

> The EQ option seems too heavy-handed and I can't seem to find any 
> indication of the phase impact.

Don't worry about phase as long as you do the same thing to both channels.

> FFT filtering can also work but again, I'm concerned about phase.

Actually, the FFT filter has near-zero phase shift.

> I would also like to try an old analogue audiophile trick. Turntable 
> rumble is actually 180 degrees out of phase from right channel to left. I 
> would love to find a way to sum frequencies below 25Hz as (at least) a 
> first step in this process.

Edit Mix/Paste (overlap) with the invert boxes checked, after you've 
filtered and swapped the channels will let you experiment with this.