I'm building a project bass next year and will be using two MM style humbuckers. I can't decide on which type to go with though. The only one I have experience with is the Seymour Duncan Basslines SMB-4DS. Here's the options I've considered: 2 Seymour Duncan Basslines SMB-4's with the SD preamp 2 Bartolini MM's (C in the neck, X in the bridge) with a Bartolini NTMB preamp (3 band, with mid select and active/passive) 2 Bartolini MM's (C in the neck, X in the bridge) with an Aguilar OBP-3 preamp (3 band, with mid select and active/passive) How would these pickups sound running in passive mode? Also, would it be worth my time (or even be possible) to wire up this system with a series/parallel switch for extra tonal variety? Last questions (I promise), would these setups require an 18V power supply? If I ran them off of a 9V power supply would the preamp quickly run out of headroom because of the two pickups? Just to clarify, price isn't a concern (as tacky and pompous as that sounds....), and I'll be using this bass to play in a rock/hard rock/grunge/little bit of metal/little bit of punk type arrangement. I'll mainly be playing fingerstyle and with a pick, with the occasional slap/pop thrown in for spice. Thanks in advance for the help everybody!