Rimmer founded the electronic music studio at the University of Auckland in 1976 and the Karlheinz Company in 1978.
His works have been performed internationally in Asia, Australia, New Zealand, Europe and North America.
[2] Rimmer and his wife Helen reside in Tapu Bay, Kaiteriteri, New Zealand.
Notable students include Susan Frykberg and Dorothy Ker.
Rimmer received a number of prizes and awards in recognition of his contributions to music, including: Rimmer composes for stage, orchestra, chamber, choral, piano, and electroacoustic performances.