Pickups:
Starting with the Seymour Duncan Pickups, the bridge pickups is the MM style 'SMB-4D', and the neck pickup is the Quarter Pound P 'SPB-3'. The SMB-4D us a hum-canceling pickup offering a balanced, highly musical tone contour with a richly articulated bottom, with lots of midrange, and the treble has a great bite. The SPB-3 pickup features quarter inch diameter pole pieces expanding the magnetic field an extending the frequency ranges for a fat, full, punchy sound with tremendous mid-range presence and maximum output. Though often used for heavy rock tones, this pickup gives amazing tonal versatility to a single pickup instrument making this the most popular Seymour Duncan Bass pickup.
 
Controls:
The Master Volume knob features a 'Series-Parallel' Push-Pull pot wired for the MM SMB-4D bridge pickup. In 'Series' (Down position) the Seymour Duncan MM is wired as a high output Humbucker with massive low-end and amazing midrange attack. In 'Parallel' (Up position) still hum-cancelling the pickup has a wonderful vintage tone rounding off the midrange and focusing on a sparkling treble tone.
 
The 4-Way Rotary Pickup Selector Switch gives you the option to combine the bridge and neck pickup in series or parallel.
 
Position 1 - Bridge Pickup
Position 2 - Bridge & Neck in 'Parallel'. This is the normal side by side wiring method for two bass pickups. This position retains brilliance and additional clarity on the high end.
Position 3 - Bridge & Neck in 'Series'. This humbucker wiring method adds 30% output compared to Parallel adding a fuller, more powerful sound. Taking the SMB-4D and Quarter Pound SPB-3 pickup, both massive on their own, and then selecting the 'Series' position you get a Superbucker that results in inspiring and groundbreaking tones.
Position 4 - Neck Pickup

Seymour Duncan 2-Band Active EQ with 18v system adds even more tone shaping versatility. This enables the player to add or subtract EQ at center frequencies voiced specifically for electric bass. The lows are deep, clear, and tight. There are two treble 'dip switch' frequency centers to choose from. The lower setting is perfect for adding growl and bite to traditional P, J, and MM tones. The higher setting provides crystal clear top end to modern-sounding, full-frequency bass tones with punishing clarity without any brittleness.