crazy frequencies in bass lines

[iluvsmebass]

how would someone go about creating a bass line where the frequencies seem to cross, like this for example, not the first bit but the drop.

http://www.youtube.com/watch?v=dtaJ5hBUjuQ

kind of like harmonics on a guitar but synth like obviously

 

[RevTech]

The frequency shifter in massive is quite popular for that type of sound.