How does music get onto a cassette tape? — Paul, age 9, Adelaide
Hello Paul!
That’s an ideal query. To reply it very briefly, music is recorded onto a cassette tape utilizing electrical energy and a magnetic subject. Now let me clarify what I imply by that.
Sound will get was electrical energy
Think about you’re singing right into a microphone whereas enjoying a guitar. While you sing, you employ your vocal cords in your throat, your mouth and your breath to make the air round you vibrate — and these vibrations are what create sound.
Equally, whenever you pluck or strum the strings of a guitar, this causes the picket physique of the instrument to vibrate, which additionally vibrates the air contained in the guitar, creating sound.
Each the microphone and the guitar “pickup” (a particular sort of microphone for “choosing up” sound from an instrument) have tiny magnets that vibrate with the actions of air, and produce {an electrical} present.
The present flows via the microphone and guitar cables to the tape recorder, via which a plastic tape is slowly shifting. {The electrical} sign creates a magnetic subject within the recording head and that is what permits sound to be recorded.
However what occurs throughout the tape recorder itself throughout this course of?
How magnetic tape works
A cassette tape is a plastic shell that surrounds two rotating spools.
A set of cassette tapes/
Mike Flamenco/unsplash
One other lengthy, skinny piece of plastic is wound across the spools. That is the “magnetic tape” on which the sound is recorded.
This tape is roofed with a magnetic materials that accommodates iron, and which reacts when it comes near a magnetic subject. The fabric could possibly be iron oxide, chromium dioxide, or generally barium ferrite.
A diagram of a magnetic tape recorder exhibiting the mechanical components.
College of California Santa Cruz Digital Music Studio
Within the diagram above, we will see the essential components of a tape recorder. Right here’s what occurs when an empty cassette tape is used to file sound.
The magnetic tape begins on the availability reel and a motor on the takeup reel winds the tape previous the heads (4, 6, 7). Every head accommodates metallic coils. When electrical energy is shipped to the coils within the file head (6), it generates a tiny magnetic subject.
When the tape enters the magnetic subject generated by the file head, the magnetic particles on it align in proportion to the energy of the sector. The loudness and pitch of the sound (how excessive or low it’s) make the magnetic particles align in numerous patterns because the tape passes via.
Later, if we need to play our recording again, we wind the tape previous the play head (7), the place the sample of the magnetic particles recorded on the tape produces {an electrical} sign that’s transformed again to sound.
These particles will keep in the identical association until they’re uncovered to a brand new magnetic subject — so a tape might be performed again many instances, till it wears out!
The remaining head is the erase head (4). This lets us erase sound from a tape through the use of a continuing electrical cost to “reset” the magnetic materials on the tape because it passes via, erasing any earlier recordings.
The capstan, rollers and arms all assist to maintain the tape stretched out because it passes via the heads, in order that it strikes on the identical velocity and will get a good-quality recording.
Just a little historical past
Cassette tapes had been developed by the corporate Philips in 1963.
A picture of the primary mannequin of compact cassette tape bought by Philips within the Sixties.
Philips USA
Though recording to tape had been doable for the reason that Nineteen Thirties, the know-how was giant, awkward and costly. The Philips Compact Cassette was low cost, moveable (sufficiently small to hold round) and could possibly be used at residence or within the workplace, with fundamental recording tools.
However when Masaru Ibuka, the co-founder of the Japanese firm Sony, needed a approach to hearken to his favorite music on lengthy flights, he sparked an invention that may change the best way we listened to music perpetually: the Sony Walkman.
The Unique Sony Walkman TPS L.
Binarysequence/wikimedia
The Walkman was launched in 1979 and introduced music into each a part of our lives. Not simply our houses, or automobiles — however wherever at any time! It is kind of a conveyable cassette participant that connects with headphones.
Since then we’ve seen enormous enhancements in moveable music know-how, with MP3 gamers popping out in 1997 and ultimately the Apple iPod’s launch in 2001.
At present, we don’t even want a particular system simply to file or play music. We will do the whole lot on our telephones! However cassette tapes had been the primary invention that allow individuals simply file and play on the go.
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