Perhaps a layer separator?

[xLixingx]

So…what did you mean?

[amak11]

He saying the effects GH/RB does on it's tracks can be copied and applied to these games. Which is possible in FoFiX and should have been already implemented from way back in the Alarian days, probly even earlier. BUT this only applies to multi-tracks

Single track files, which has been explained already is pointless to apply any audio filters or modules as it will make the audio sound terrible as you quite plainly witnessed in your first post.

Hmm, how about parametric equalizer? we know frequency of guitars(bass too), vocals, drums(oh god..) so just gain them up while playing right and down if messed
In gh wt they are gain up current instrument audio track i.e. bass at bass career can be easily heard against guitar career...

Just no, GH uses master tracks same as RB. They raise the volume of the track you are playing in early GH titles, pre-GH5 and GHVH. That doesnt happen in GH5 and WoR. What you're suggesting wont work at all in any way without killing the audio you are trying to split.