[quote name='LukeFRC' timestamp='1336589977' post='1648132']
passive as in passive pups and no preamp? hmm, if their is a preamp in there pull the volume to turn it off and see how that effects it. Other than that I would check the string heights. Also check the break angles at both the headstock and bridge end. The bridge is cool that you can effect height an break angle semi- independently. Oh and when you do all this set the EQ flat on your amp... if you're just using headphones it could be something to do with how they process bass frequencies....
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Indeed, it is purely passive. MEC jazz type pickups, no preamp. I do have an active Corvette too, but its in for a repair at the moment so I can't check it out. I have changed the strings and given the bass a setup. The headphones are for my home practise, and everything sounds good. It's when cranking it out through a full rig that the differences appear between basses. The Rick and Fenders sound fine, but the Warwick goes weedy on the top two strings. I will arrive early for this weekend's rehearsal and see if I can mess with the settings to improve things