The bass guitar and kick drum have common traits which can work together to achieve a powerful musical result. Often unnoticed, these similarities sometimes compete and interfere with each other, muddy the mix, confuse the listener, and reduce the power of the musical experience.
The first and perhaps most obvious of these common traits is their fundamental frequency range: LOW. The bass guitar's fundamental tones and most interesting overtones include frequencies from about 60 Hz up to about 1 KHz. The residual noise after a kick drum hit can cover a band of frequencies from below 20 Hz to about 100 Hz. I think of the kick's sound as having two parts: an initial attack which covers a broad band of frequencies from 100 Hz. to 15 KHz. followed by a (pitchless) decay in the 20 Hz to 100 Hz range. It is the second 'part' of the kick's sound which competes with the bass guitar.