Solid bass advice?

So I'm having a bit of trouble getting a nice clean bass with a kind of punch at the beginning then levels off. Kinda like the bass used for the more "authentic" dubstep. e.g Mala, Benga, Etc. I'm having a hard time getting a bassy sound with little to no distortion but a good presence. I use Reason 5 and mainly Thor but i have heard the sub tractor is good for this reason, is this true? can anyone shed some light on this for me? Sorry if this is kind of scattered I wasn't sure how to word it I guess. Anything is helpful.