I have a Warwick bass that I have been piecing together. MEC mm humbucker bass pickup from a Warwick FNA Bass. It has a double white wire no wire harness so I don't know if it's passive or active but my body has a spot for a 9 volt battery which I bought from the same person I bought the humbucker from i always thought it was active but any other active pickup I have has a red wire with it.