I used to have this compressor - very nice for the price. However since I started using an active bass, I could hear a pop artifact when the compression was kicking in.
With my passive bass I bought the LMB-3 for, my settings were Volume at 12 o'clock, Enhance Off, Ratio around 11 o'clock and threshold at 13 o'clock.
best way to find the settings - play a lot with it!
hope that helps