Watch the Reptile Funk online guitar lesson by Stu Hamm from Essentials: Funk Bass Grooves
Notice how we have to move back to the neck position pick-up to get that "old school" tone. Experiment playing this line with different pick-up configurations and see how to get the best tone on your own bass. You can also lay into the notes to get some bite out of your strings without popping them. Take the time to work out the unison line well in advance so that when it's time to play it you'll NAIL it.