Adjustable frequency bands on the equalizer. Like a button "advanced mode" below the equalizer which when typed shows buttons below all 9 bands. Lets say u choose 2k and the line appears (similar to bands) that goes from (examples) 1.501kHz to 3kHz so. And if u chose 4k the line goes from 3.001kHz (yes 1 Hz higher than the max of the previous band) to 6k. The PC app "Fx Sound" does this well but on mobile all equalizer apps that have the feature also have broken equalizers (actually every eq app is broken). SAMSUNG MUSIC ALREADY HAS THE BEST MOBILE EQUALIZER that works and SOUNDS well and can completly change the speaker. BUT if this idea was implemented it would create endless sound possibilities for users.