Today, cassettes seem like something from the past - nostalgia for the 80s and 90s and a little bit of the 00s. But behind this seemingly simple technology is the real magic of physics and electronics.
How does the film work in the cassette?
Inside the plastic box there is a long magnetic tape. It looks like a dark shiny strip, but is actually covered with a layer of ferromagnetic particles (metal oxides). These particles can be "magnetized" and they are the ones that preserve sound.
How sound is recorded
Microphone or sound source converts air vibrations (sound) into an alternating electrical signal.
Recording head in a tape recorder, it creates a magnetic field that changes synchronously with this signal.
When the film passes by the head, its particles "orient" under the action of the field - an invisible "imprint" of the wave is formed.
As a result, a magnetic trace is stored on the film, which repeats the shape of sound vibrations.
In fact, a cassette is an analog "map" of sound in the form of changes in magnetic fields.
How and why does the cassette "play"?
When the film moves by reproduction head, magnetic changes on the tape are converted back into an electrical signal.
This signal is amplified in the player circuits.
Finally, it hits speakers or headphones and we hear the music again.
Interestingly, the head actually "reads" the invisible magnetic code embedded in the film particles.
Why can the cassette erase and overwrite?
The same film particles can be magnetized over and over again. If you send a new signal to the recording head (and sometimes also additionally "erasing" with a constant field), the old recording disappears, and a new one is stored on top of it.
A cassette is an example of how complex physical processes were embodied in a compact and convenient form. No files or hard drives - just thin film, a little magnetism and mechanics that move the tape evenly.
No wonder cassettes are returning today as an element of retro culture: they have the warmth and feel of "live" sound that no digital format conveys.
Nostalgia plays a big role in modern pop culture. From the last thing I saw in my bubble, a film cassette release by Dodo Socks (https://www.instagram.com/dodosocks/). A good marketing ploy, aesthetic content and just a cool thing to keep as an interesting cultural attraction that in 30 years' time can be looked at with a tear on the cheek.
Share this post
Cite post
Select and copy the required citation standard:
This post doesn't have any additions from the author yet.
