Gordon, a customer from Spain recently asked me a question about ID3 tags on his backing tracks.
He also noticed that all his mp3 backing tracks have a strange .sfk file attached to each one and wants to know what this .sfk file is….
I forgot to mention, some of my mp3’s have an sfk file
attached to them! What is a sfk file?
Files with a .sfk extension are usually associated with, but not necessarily restricted to, the Soundforge range of software audio programs (but could be any program that uses their audio processing “engine”).
A .sfk file is basically a little “extra” file that often accompanies the main audio file and contains information that helps your computer draw a representation of the waveform of the audio when it’s opened up in a waveform editor (like Sonys Soundforge, Acid Pro etc).
Most times it’s safe to just delete the .sfk file but sometimes it is needed for the information it contains.
A simple way to find out if it’s “surplus to requirements” regarding your system and is to do a small test. Delete one of the .sfk files and then play the corresponding audio file. If it plays ok and your audio player can still read all your ID3 information and any other file information you usually see without any problems, then you’ll know it wasn’t needed.
Mind you, .sfk files are usually VERY small files (because they only contain information, no actual sound data) so they don’t take up much room at all. For that reason, if they don’t bother you then you could leave them as they are…