This is from the manual:
"...with a range of 22 Hz to 22 kHz in the audio frequency mode.
In low frequency mode, the total range is
2.4 mHz (a period of 7 minutes) to 180 Hz, with
1 Hz when the knob is centred."
In other words, Orbit 3's LOW mode can get you into audio rates (up to 180 Hz), but I don't know how that compares to Zlob's module and if that is an improvement for your purposes.