sometimes i use subbass effect. also i use bass samples/filtered bass from vinyl, it can be tough coming with basslines that way with this machine without a good pitch function
Any keyboard & I mean ANY keyboard any sound you bring it down to the lowest octave and you have many bass possibilities- sometimes you just need a couple notes to trace a sample.
sometimes I'll use Isolator, kill the mid, kill the high, turn up the low. Other times I'll just use the bass on the sample, and sometimes I'll record in a bassline with my shitty bass guitar.
i use reason to sample a nice bass line into my sp then do as i wish with it with the 555's effects and what not but i cant play the keys well but bass i dont think you really need to know to much as long as its with the beat i think
I would probably use the isolator resample that, then use the sub bass effect and resample again. To go further you could chop individual notes/tones onto separate pads.