Renaissance Bass.

Renaissance Bass generates harmonics that make the ear hear bass a speaker is not actually producing, based on psychoacoustic research rather than equalisation. That distinction matters, because it does not muddy the low end the way a boost does and it adds bottom without consuming headroom. You balance the original and enhanced bass against each other, and clip protection keeps gain staging simple. It works on music and voice alike, and matters most on earbuds and small speakers.