Fostex began in 1973, developing technology for speaker components, creating their well-known Regular Phase (RP) technology just a few years later, and pushing their T20RP monitoring headphone out to studios across the world. Fostex has continued to innovate over the years, in the studio/recording realm and with many products for the home listener. The Fostex T50RP is another studio legend that became the favorite modding platform of many headphone enthusiasts, and the Fostex TH900 took the market by storm with its sophisticated design.