An apparatus, system, and method are disclosed for dynamically controlling
a recording head substrate bias voltage. The apparatus includes a
midpoint module and a substrate module. The midpoint module calculates a
midpoint voltage of a plurality of data read elements and servo read
elements contained in the head. The substrate module calculates a
substrate bias voltage. The apparatus, system, and method dynamically
control the substrate bias voltage post-assembly, minimizing certain head
degradations and extending the life of associated head readers.