Worth noting that in bass music, like Drum n Bass, the kick will often sit above the sub bass in the mix. Sitting the kick higher up around 80-120hz lets you fill the low end with bass/sub bass elements. You will need to make room for each one in the mix, so try not to have too much kick weight under it's fundamental range that's going to fight the sub for space. Make dips and cuts in the bass for the kick, too.