ELI5; Scientifically, how do cassette players work?

Question

I mean it’s just strips of plastic

Edit: What I mean is how does the VCR machine/walkman read the strips of plastic to make the video/souund?

In: 0

Answer 1

It’s strips of plastic, yes, but with a magnetic coating.

During the recording process, the sound is converted into electricity and supplied to a recording head, which generates a magnetic field that slightly changes the properties of the magnetic coating of the tape.

This process is deterministic: a given pattern of sound will create a given pattern of magnetic particles.

It’s also reversible — the magnetic tape can be passed over a playback head, which will respond to the magnetic properties of the tape and generate electricity, which is then converted back into sound at the speaker.