ritual (free software) to create bass

Tweakbench

ritual is an analog style bass synthesizer that uses several unique techiques to create a thick & rich sound. oscillator 1 is a blend of a pulse & crushed triangle, while oscillator 2 uses a custom designed super-saw blended with a crushed sine. the synthesizer also uses a custom designed cascade filter system with a feedback chain for adding analog warmth to the sound. lfo and envelope modulators can target 8 different parameters in both positives and negatives using the modulation matrix.

download
http://www.tweakbench.com/plugins/tb_ritual_1_0.zip