i think you make make 'low-end' in any synth, that's the idea of a synth surely. what program are you using? and what sort of low end do you mean? sub bass?
If you're running LOGIC the default patch for the EXS24 sampler is a heavy sine wave.
Just tweak the release and you're good to go. Throw a mid range lead over it with the same notation data on that track so they sync up. Sometimes on the lead I'll put the LFO set to filter cutoff so it sounds warped.
for a sub bass u don't really need any advanced synths imo, as sub is inherently a simple sound, like some of the guys said if ur using FL 3xosc should do fine, Reason Subtractor and Malstrom will do the job (i use Malstrom for my subs in Reason)
go on zeta. preset integrated fifth then turn off all oscillators and effects etc then jus add a sine to the first osc and add various affetcts as you see fit.