If I understand you in right, i my music I use bass as low end drone content. Because I grown from metal (black, doom), so I explore ambient, drone, noise from this perspective. I have basicly two ways in creating music. In first way I generally start with heavy distort bass, I try decompose riffs to simple heavy drones and later create drums, synths, noises. In second way I create drums/rythmic patern, next add synths and noise and last is bass drone. In Iglau Atonal I try create impro/live noise by synth in mids/highs and use bass for lows. My idea is full specterum noise music. But I am new in improvisation so I go trial and error.