Fostex was established to brand high quality speaker components from Foster and sell them direct to consumers and dealers in the Japanese marketplace. This area of the speaker component business is still something unique to Japan where there continues to be a high number of individuals designing and building their own speaker units at home, some for sale but many just for personal use. Indeed even today speaker component business still represents a major part of Fostex’s monthly domestic income although sales are slowly enjoying a renaissance in other territories.

Fostex speaker components initially won acclaim because they were an early developer of RP (Regular Phase) technology which provides for a very clear sound with high sensitivity and wide dynamic range. Today RP technology is well known worldwide not just for speakers but also microphones and headphones, with the Fostex T20RP being one of the most popular studio monitoring headphones in the United States.