<< APF is a technique. Users can right click any track in the mixer, and convert that track into an APF, which is essentially an audio file. It is equivalent to rendering to a WAV file first, then import the WAV file back to the same project as an external audio file. In short, APFs are exports. >>

Not exactly. An APF is a conversion process so BIAB can recognize an audio file on another track besides the single audio track. This feature has been expanded to include the 16 additional Utility Tracks. The conversion doesn't involve any exporting or importing. The APF WAV file is saved without rendering. The process is faster than rendering and saving a WAV file.

<< APF used to be used as sub-mix files because users don't have enough mixer tracks. However, with the introduction of utility tracks in BiaB 2021, users now have more than enough mixer tracks, and APF is no longer needed or useful that much. >>

My thoughts about an APF's value is it's now 16 times more useful than prior to Utility Tracks being introduced. It's now much easier to remain in BIAB before exporting to a DAW and in many, if not most cases, eliminates the necessity to use a DAW for a lot of tasks where exporting has previously been utilized. In comparison to the analog world of multi track recorders, BIAB is the equivalent of updating from an 8 track to 24 tracks. All of the multi track editing and recording principles, functions, techniques and processes remain the same.

For users wanting to remain in BIAB as long as possible, learning to implement APF's provides a tremendous advantage.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.