I want to actually trim out part of my audio in source window. I don't want a sub-clip which seems to be linked to actual full source audio, but rather to modify the source buy cutting out unnecessary part of it. Cannot find the tool to do that.
Adobe Premiere is Non-linear editing application. Any changes made in it don't have any influence on footage on your hard drive. Not audio, not video.
It is feature, which prevent damaging footage files.
It is based on trimming, not cutting. However, if you really want it, you can trim your audio, export it from Premiere, and then import back. But I can't find any reason, why you can need that.