Friendly Stereo Sub

As most sub-bases are mono, there is a shortage of tips & techniques for creating stereo sub-basses. Therefore, here I will walk you through how I made a patch in FM8 and why I chose the settings I did. It is meant to be used in a booming Hip Hop or Pop production but could also be used in Dubstep or House music. In short, the key to a good synth bass is subtle movement. Each parameter should be finely tuned by ear to your liking after making these course adjustments. The patch sounds like this...

OPERATORS

1 Sine wave carrier (F)

Firstly, route 100 percent into Z (low pass filter). Low pass filtering is a hallmark of good synth sub-basses.
Secondly, Turn Key Sync On. This will make the waveform cycle start at the beginning of each trigger.
Then, Push Velocity up to 27 percent. This will make the synth more sensitive to differences in velocity while recording or after drawing in velocity values.

1 Sine wave modulator (D)

Modulating carrier (F) by 60 percent. This will create a desirable amount of sidebands (added frequency content).
Ratio of 2. This means the frequency of the modulator will be twice that of the carrier, no matter what note is played. 1 LP filter (Z)

Route to output 95 percent. We don't want to overdrive the filter, but we want it hot.
Cutoff around 1 kHz. We need those characteristic sidebands to be there when that modulation sweeps in, but we want to cut them off at about 1 kHz for more control and a better mix.
A little bit of resonance. This provides clear separation in the mix, and the bass gets distinct.

Envelopes

Carrier

Attack - logarithmic, 50 ms.
Decay - 25 ms.
Sustain - 90%
Release - logarithmic, 250 ms.

Modulator

Attack - smooth,
logarithmic 800 ms attack.
Decay - none.
Sustain - 100%
Release - logarithmic, 150 ms.

Filter

Attack - immediate.
Decay - none.
Sustain - 100%
Release - logarithmic, 450 ms.

Modulation

Active LFO - triangle or sine wave contour, whichever you prefer.
Eighth note rate (Sync on).
Modulate the amplitude of the modulator by 100%. It will be interesting to automate this parameter after you're done with the patch.
Delay by the duration of the modulator attack (about 800 ms in this case). Having the modulation sweep in at the climax of the modulator's envelope is a common effect in bass synths.

Master

2 voices, detuned and panned out about 25%.
Set polyphony to Mono. This does not mean the output will be mono; you can only play one key at a time.
Turn up the analog quality by about 30%. This will add some natural-sounding warmth to the noisy floor.

FX

Short, bright, and dry Reverb. It is essential, but you should barely be able to hear the decay. As a result, it should just provide a sense of space to the low-mid range.