Pictured here is the “Triple Pickup” system designed for the S-12 harp guitar. Paired with the L.R. Baggs M1 active sound hole mounted humbucker, is the “Flat-Pup” thin humbucker mounted directly to the top under the harp strings. Wired in stereo they can be controlled externally with a stereo-Y patch cable, or summed to mono and blended with the on-board volume of the M1.
There is a 2nd jack installed with our house made 3-Contact Passive Piezo system glued to the bridge plate strategically that can then also be added to your mix. Piezoelectric pickups are higher impedance and cannot be summed with the magnetic humbuckers. The signal will need its own mono patch cord, but can then be blended with the humbuckers using separate mixer or preamp channels.