[LAU] noise reduction

[Ralf Mardorf]

On Sat, 23 Jan 2016 14:58:29 +0100, Hermann Meyer wrote:
>Maybe this one is of some help:
>http://www.penguinproducer.com/Blog/2012/01/ladspa-noise-removal/

"this does not remove the background noise during those parts where
there is a signal"

So IIUC "The problem at hand is hiss, so the kind of thing you could
remove with a LPF, but in the process damage the recording by removing
the sparkle..." this doesn't help the OP.

Even using a notch filter in combination with a dynamic multi-band
effect would have much impact to the "sparkle". I suspect that only a
notch filter is able to keep the "sparkle" and to damp the hiss a
little bit. Assumed the filter could be used for individual tracks
instead of the sum, its to consider to use dynamic effects too.

However, you can't fake Dolby and Co. for recordings that were already
done without Dolby or Co., you only can provide a smarter kind of noise
gate e.g. a gate that behaves different at different frequencies.

Using an expander and after that a compressor with a different ratio
and/or threshold seems to be not as smart as using a multi-band dynamic
effect just to gate or compress a signal depending on the frequency.