The Basics of a Sine FM Bass in Serum

The blend between the gain of A and B creates different characteristics. Oscillator A is the sub, on minus 2, and makes it crunchy. Oscillator B is the higher part, on plus 1, and makes the sine FM characteristic. Make LFO 1 an envelope and add it to the level of A and the level of B. I like to add the sub oscillator on minus 2 as well, for more crunch.

With distortion on diode 1, play around with the semitone of B and put it at around plus 5 or plus 7. That's where you already hear the sine FM characteristic. I like to use the digital harmonic series instead of a normal sine wave, and play around with the wavetable position. Take down the randomized phase on both.