How would I go about separating bass and treble into separate tracks?

[lschlick]

Suppose I have a track A. I want to create two tracks, B and C, such that:

1. When B and C are mixed together, they create track A.
2. Applying an amplitude of X db to track B before mixing B and C together has the same effect as applying X db of bass to track A using the “Bass and Treble” tool.
3. Applying an amplitude of X db to track C before mixing B and C together has the same effect as applying X db of treble to track A using the “Bass and Treble” tool.

The reason I want this is because the “Bass and Treble” tool only allows adjusting the bass and treble levels by a flat amount over the selected area. It does not allow you to adjust the bass/treble continuously. If I was able to isolate the bass and treble into different tracks, then I could use adjustable fade and the envelope tool to adjust the bass and treble levels continuously.

For example, some songs that I process have sections where the bass is much louder. Or the bass gets louder or quieter gradually over time. If I could isolate the bass into a new track and use envelope tool to even out the bass levels over the course of the song then that would make my life easier.

Is there some built-in effect in audacity that could do what I am describing? Or some free plugin that I could use?

[djksette]

Sounds like you’re wanting to use Stems for this.

[steve]

The easiest way is to use the High-Pass and Low-Pass filters. If a low order crossover (6 or 12 dB/octave) is OK, then this will work fairly well, but not so well for steeper filters.

If you need a very abrupt crossover, then you would need to use the Filter Curve EQ. Editing the curve parameters in a text editor will be the best way to get the crossover frequencies and levels accurate.

[lschlick]

Low pass filter and high pass filter worked great. Thanks!