The Fostex T50RP utilizes a newly designed development called anRP Diaphragm. This unique Fostex technology employs a copper foil-etched polyimide film to provide resistance to high level input peaks of up to 3000mW combined with a neodynium magnet for high sensitivity and excellent transient handling. These are excellent quality headsets with Regulated Phase, a new transducer technology which offers the finest quality audio reproduction. Fostex headphones are used by professionals on stage and in studios the world over.This combination lifts the quality of the T50RPs audio reproduction above that of the already superb T40RP and T20RP. In short,the T50RP offers perhaps the most natural and uncolored sound yet heardfrom a pair of studio headphones.