what kinda bass do you have? fleas tones tend to be heavier on the low end, low mids and highs to give it a real deep sound while using the highs to accent he slaps (i guess?) but it depends on your bass...
if you have a p-bass with high action it might be hard to get a great sound out of it but you can def make it happen with some technique, the right strings/set up and enough toyin around on your amp.
Good luck man!