I discovered a way to bring somehow a LFO in the audio path adding even more bass to the sub37. Here are the basics to start:
- Init preset
-LFO1 : Mod destination FDBK
-LFO1: keyboard track 100%
-Mod bus1 : set Mod wheel amount to 0%
-LFO1 keyboard tracking 100%
-LFO1 range : high
-Switch off all the oscillators
-LFO1: select a wave
-Mod 1 amount around 3 (vary at will)
-Feedback around 7 (vary at will)
- Play and tune the LFO frequency
Sound is a bit like an electric bass thru a slightly noisy amp. It can be seriously low and loud: watch your speakers
- Add the other oscillators

Have fun!
Hans