Consumer Formats Flashcards
What music format was available in the 1870s? What were their disadvantages?
Wax Cylinder Players, largely physical and easily degradable.
What was available in the 1920s? What were they made of?
Gramophone.
Records were made of very fragile shellac
What music format was available in 1950s?
Vinyls.
How is sound stored on a vinyl? /3
On a single groove (waveform). Each side of the groove has a separate signal for stereo.
The stylus/ needle has a sapphire/ diamond tip.
Vibrations are converted into electrical signal.
What are the disadvantages of vinyl? /2
Not portable, needs flat surface for player.
Prone to feedback.
How does the speed affect the sound quality of a vinyl?
It deteriorates towards centre of record because of constant rotation speed (varying amounts of vinyl per second under stylus)
What is an RIAA curve?
Standard playback equalisation curve for LPs and record players.
How does the RIAA curve work?
Low frequencies are reduced on record, to reduce wide stylus movement.
EQ applied on playback to return low frequencies to correct level.
What are the different sizes and speeds of vinyls?
7/10/12 inch
Speed in rpm 33/45/78
What is the frequency response of a vinyl?
What happens below that amount?
30Hz - 30kHz
Under 30Hz is prone to rumble
What are vinyl records susceptible to?
Scratching and dust, that causes crackle, hiss and jumps.
Warping if exposed to heat
How does vinyl attract dust? How can it be removed?
By creating static charge.
Special dusters and polythene sleeves reduce static charge.
What format overtook vinyl? When?
Cassette tapes in 1970s.
Why were cassette tapes more practical than vinyl?
they were the first type of portable format.
How did cassette tapes work?
They were magnetic, coated with iron oxide. Electromagnetic induction makes the particles form in a pattern if the signal is musical.
How did the size and speed of the tape affect the sound quality?
Reduced high frequency response, prone to hiss and saturation.
What does the capstan do on a cassette?
Controls speed of tape.
What are the common tape lengths?
60/ 90/ 120 minutes.
What are the three types of bands on a cassette?
Mono: 2 tracks (1 on each side)
Stereo: 4 tracks (2 on each side)
Multitrack: 4 tracks (tape plays one way)
How was hiss reduced on cassette?
Dolby noise reduction.
What is print through on a cassette?
Music is heard as an echo before it should play.
What is degaussing?
Removing the build up of magnetism on tape head, reduces distortion and improves sound quality.
What were the disadvantages of cassette?
Tapes could be snapped, tangled around the heads.
Difficult to cue/ locate tracks.
What is tape bias?
Improves fidelity of tape.
What is DC bias?
Addition of direct current to recorded audio signal.
What is AC bias?
Addition of inaudible high frequency signal
How does a higher tape bias affect the quality of a tape?
Better signal to noise ratio and sound quality.
