[LAU] Synth: Dubstep Bass

Hey all, I used to produce some dubstep songs (totally synthesized) using various proprietary solutions, but I'm recently attracted to the bass frequencies again. Hence I'm looking for a good synth for bass, with plenty of assignable LFO's, Portamento, and... sounding good! I've a little experience with MX44, another little bit with AlsaMod Synth, a bit of a giggle with ZynSubAdd, a play around with the recent Yoshimi, but I'm not convinced of any really heavy bass yet. Chances are that I've not got the right settings for the synth, Just wondering if there's any dubstep guys out there using linux synths, or if anybody has any PD dubstep patches? Cheers, -Harry