audiocassettes

An audiocassette, commonly known as a compact cassette, is a small plastic cartridge that contains a length of magnetic tape used for recording and playback of sound. It was developed by Philips and introduced in 1963 as a consumer audio format, quickly becoming widely adopted for music distribution and home recording. The tape is normally 0.15 inches (3.81 mm) wide and runs at a speed of about 1 7/8 inches per second (4.76 cm/s) inside a protective shell with two reels.

Cassettes are read and recorded by tape players and recorders that use a set of heads: erase, record, and playback. Sound quality depends on the tape formulation, track layout (mono or stereo), head alignment, and biasing circuitry. Common durations range from around 30 minutes per side to 45 minutes per side, with total lengths of 60, 90, or 120 minutes being typical for consumer tapes.

There are several magnetic-tape formulations. Type I ferric-oxide tapes provide affordable, ordinary bias performance. Type II chromium dioxide (CrO2) tapes offer higher-frequency response and better dynamic range. Type III ferro-chromium is rarely used today. Type IV metal-particle tapes deliver high output and wide dynamic range but require different equipment and biasing. Each type has unique handling and playback considerations.

Durability is a concern: tapes can deteriorate due to age, heat, magnetic exposure, and mechanical wear. Cassettes require proper storage and gentle handling to preserve fidelity.

Today, the compact cassette has largely been superseded by digital media, but it remains culturally significant and experienced periodic revivals through limited releases, reissues, and cassette-based archives.