Wulf X Gutz dead body bass?

[BIG]

This track is just huge on so many levels
https://www.youtube.com/watch?v=4q8Y-skXM7M
but that bass is so unique sounding
to me it sounds just like a really pitched down sin wave but I can't figure out what the mid range sound is on top
i'm using massive btw but I can still use things in reason.
i'd love to see what people can figure out about this sound