What kind of bass do you have? (that what profiles are for ) Certain basses are more well known for their "growl" than other. Jazz basses and Rickenbackers are known to growl, (in my ears), but as for amp setting, you might want to boost your mids. A scooped eq setting doesn't growl very much, but that's just me. Also, if you have a bass with two pickups, try to emphasize the bridge pickup. Or, you could use a pick, but I don't like picks, which is a personal preference, and has nothing to do with what you do. Mmm... ramblings...
id also like to kno this i got a prince 20 watt amp and it has 3 knobs...trebble bass and level(volume) sorry for stealing ur thread!!
You could try a little EQ boost around 800-900 Hz. Remember though, EQ can't bring out what's not there already, so if your bass and/or your hands don't "growl" already, your amp won't make them do so either.
...indicating that it's not just one thing that does it. IME it's tough to get it out of a P-style pickup -- it's easier with a single-coil PU closer to the bridge, since that position accentuates the 700-1000 Hz band where "growl" lives. Also roundwounds will help -- also tough to get growl out of flats. And of course, boost 800-1000 Hz on your amp,if you can. This is where I like to plug the Tech 21 Acoustic DI, which allows you to overdrive a selectable midrange frequency. I suggest bringing your bass and amp to a music store that has one and try it out. Switch it to "active" mode, set mid for 800 hz, mid level at 3:00, and crank up the Blend. See what you think.
If you use that eq with a J-style bass and a tube driven preamp like Ampeg, Mesa Boogie or SWR with just a mild overdrive boosting your input signal I've found that should get a good growl.
If by growl you mean "edgy", or not a smooth warm sound, then that's pretty easy. Boost your mids and bass, if you have a tone knob turn that up, don't play too close to the neck, and if you want, a pick will give you that sound. If that's not what you mean by growl, then.... oh well.
It will also help if you play close to the bridge. My Jazz and my Carvin both have the single coil pup in the bridge position. If you really dig in near the bridge it will growl like a beast! mmmmm.........growl.......
If your bass has 2 pickups, try with play in the one closest to the bridge, if you have a single knob for adjusting the pickups, try putting it about ½ more to the bridge pickup that to the other.