F-REX can analyze the sound that's being played in real time into the three parameters 'Gain', 'Frequency' and 'Panning' and graphically visualize them.

You can independently control the inside and the outside area of the specific part focused by panning and frequency. You can apply effects (compressor and reverb) inside and outside the area, and adjust volume and panning intuitively.

These functions can create 'minus-one songs'. F-REX can find a specific sound in the song, for example vocal part and and minimize its volume. 'Noise canceling' can be done as well. Also adjusting volume to specific instruments make the sound more audible and learn a song easier. F-REX can be used for various purposes and you can produce unique remixes sound.