According to Recording History, 8-track cassettes were manufactured containing a magnetic loop of ¼-inch tape. Each tape was divided into eight channels of stereo sound, giving the tape format its 8-track name.
History
Recording History reports the 8-track audio playback format was created under the direction of Learjet business plane inventor Bill Lear. When Lear's airplanes were equipped with 4-track audio systems, Lear was unhappy with the quality, so in 1965 he marketed the first 8-track machines.
Tape
8 Track Heaven explains that the tape held within the 8-track cartridge is played in a continuous loop, because tape is pulled from the center of the cartridge and backs around the outside of the looped tape. The tape is passed over a playback head at the front of tape to create sound.
Channels
At each time the 8-track machine reads and plays two channels of audio to create stereo sound, according to 8 Track Heaven. When the loop of tape has been completed, the playback heads automatically reposition on the next channel to play the next stereo track.
Tags: Recording History, stereo sound, Track Heaven