Mackenbach was born in Best, North Brabant and has an older brother Rick (born 1993). As a child, he starred in the musicals Tarzan and Beauty and the Beast.[3] He attended Amsterdam's dancing academy Lucia Marthas, and studied acting at Centrum voor de Kunsten Eindhoven (CKE) in Eindhoven.[4]
Mackenbach's debut album Ralf achieved a top 10 spot in the Dutch album charts and entered the Flemish album charts at number 59.[8] In March 2011, it achieved gold status with over 25,000 sales.[9]
After graduating secondary school with a VWO certificate, Mackenbach studied at the Eindhoven University of Technology. In 2019, he finished a master's degree in nuclear fusion, for which he wrote the dissertation Numerical Modelling of Mode Penetration in Cylindrical Geometries Using M3D-C1.[11]