This 2-second dubstep growl bass combines a sawtooth and a square wave one octave higher, mixed and filtered through a resonant low-pass filter with cutoff sweeping from 200 Hz to 4000 Hz. The cutoff is modulated by an LFO that speeds up from 2 Hz to 6 Hz, creating the characteristic wobble growl effect. A clean sine sub-oscillator adds low-end weight beneath the growl. The sound is saturated heavily with a tanh function for gritty harmonics, shaped with a fast attack and slow release envelope, and given subtle stereo width via a 15 ms delay on the right channel.
This bass suits dubstep and other bass-heavy electronic genres around 140 BPM, where rhythmic growl modulation fits. It can be layered with other sub-basses or mid-bass synths to add complexity. Careful EQ may be needed to prevent the saturated midrange from clashing with vocals or leads, and the stereo delay effect should be balanced to maintain focus in the mix.