DBX works by increasing the perceptible dynamic range (difference between quietest and loudest elements) of a recording. The dynamic range of a live performance may be 90 to 100dB, whereas the best obtainable result from a vinyl record without compression is around 60dB. DBX compresses the recording by a 2:1 ratio.
DBX did not achieve popularity in the consumer marketplace, as compressed recordings did not sound acceptable played back on non-DBX equipment; Dolby B won out instead, as its use of preemphasis gave far more acceptable results when played back on non-Dolby equipment. However, DBX was widely adopted in professional recording, and was used by Tascam in their Portastudio four-track cassette recorder for home studios, becoming standard on four-track cassette recorders of this type.