I recently bought a used 5 string fretless Ibanez bass. I'm trying to get the Jaco sound, and I like the Marcus funk, growl, oink sound also. Since it is fretless, I replaced the old strings with new flat wounds. They just sound totally dead. Then I tried pressure wounds, they were an improvement, but still not close to the sound I want. So I am going with round wounds. I have used Fat Beams on a 4 string, they sounded great. I have a new set of Sunbeams, don't know if they are worth trying, or should I just buy Fat Beams since I know they are good. Has anyone played on both, will I even notice a difference in tone. I want low end growl and that mid range Jaco sound. Thanks for any input.