A bass pickup has similar components as guitar pickups but traditionally had 4 pole pieces as compared to 6 or more on traditional guitars. Now days I’ve seen 3 to 9 strings basses which create a need for modern design pickups.

Early Fender single coil Precision Bass pickups had between 8 & 9,000 turns and the split coil Precision Bass had 10,000 turns per coil and wound in opposite directions for a humbucking effect. Jazz Bass pickups where wound under 10,000 turns because they had a longer winding length and if wound to hot the pickups would loose clarity and presence.

Early Gibson bass pickups would be wound with 20,000 of 42 gauge plain enamel wire and would sound full but lacked presence.

Rickenbacker bass pickups often used a .0047 mfd. capacitor in series with the output to give the pickup presence and less bottom.

Fender Precision and Jazz bass pickups usually have two poles per string to keep the output balanced as the string vibrated from side to side.