In my corner of the world: The bass guitar always needs to do the bass part, so, definition in the lower couple of octaves needs to be there. The mid range can be messed with to some extent. I don't do distorted/alt bass tones often, but what works for me is to run a Distortion block in parallel with the clean bass amp tone, and low and high passing that Distortion block with a PEQ so that just a frequency range from about 320hz-500hz to 900hz-1200hz is distorted (depends on taste, pickup, etc). Now, mix that "hair" in with the regular bass muscle until you've got as shaggy of a gorilla as you need. Scooping the mids on the clean amp a bit or some compression might tuck it in better. As far as specifics: Don't have the AX8 at hand to check: but I think that the Drive Block is a RAT with a Germanium transistor swapped in. The USA 400 Bass and 1x15 LA cab are a good choice for the core clean bass tone. As far as effects: Start out with slow rates on the univibe, phasing and time effects, and also leave the low end out of it. I'd also high pass those at 180hz minimum or an octave or more higher. I've just scratched the surface of possibilities to come up with a couple of oddball things that aren't bread and butter bass tones: but its a very big sandbox for the experimentally minded.