I have a Warwick Streamer Std with 2 pickups(5 string), both MEC "passive soapbar" (whatever that is, ive heard of active soapbar but never passive. They are slightly smaller than the humbucker on the Stingray and certain G&L's, with no polepieces.) The bass sounds very good, but i was slightly upset with its lack of active electronics, which makes it fairly quiet compared to my other bass. I was wondering if it would be possible to add in an active tone control(no pickup replacement) for better sounds and increased volume. I checked out the cavity, there is plenty of room(about 10 cubic inches of free space). About how much would this cost, and where is the best place to get hardware like this?