Consumer Formats

Question 1

What music format was available in the 1870s? What were their disadvantages?

Answer 1

Wax Cylinder Players, largely physical and easily degradable.

Question 2

What was available in the 1920s? What were they made of?

Answer 2

Gramophone.

Records were made of very fragile shellac

Question 3

What music format was available in 1950s?

Answer 3

Vinyls.

Question 4

How is sound stored on a vinyl? /3

Answer 4

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.

Question 5

What are the disadvantages of vinyl? /2

Answer 5

Not portable, needs flat surface for player.

Prone to feedback.

Question 6

How does the speed affect the sound quality of a vinyl?

Answer 6

It deteriorates towards centre of record because of constant rotation speed (varying amounts of vinyl per second under stylus)

Question 7

What is an RIAA curve?

Answer 7

Standard playback equalisation curve for LPs and record players.

Question 8

How does the RIAA curve work?

Answer 8

Low frequencies are reduced on record, to reduce wide stylus movement.
EQ applied on playback to return low frequencies to correct level.

Question 9

What are the different sizes and speeds of vinyls?

Answer 9

7/10/12 inch

Speed in rpm 33/45/78

Question 10

What is the frequency response of a vinyl?

What happens below that amount?

Answer 10

30Hz - 30kHz

Under 30Hz is prone to rumble

Question 11

What are vinyl records susceptible to?

Answer 11

Scratching and dust, that causes crackle, hiss and jumps.

Warping if exposed to heat

Question 12

How does vinyl attract dust? How can it be removed?

Answer 12

By creating static charge.

Special dusters and polythene sleeves reduce static charge.

Question 13

What format overtook vinyl? When?

Answer 13

Cassette tapes in 1970s.

Question 14

Why were cassette tapes more practical than vinyl?

Answer 14

they were the first type of portable format.

Question 15

How did cassette tapes work?

Answer 15

They were magnetic, coated with iron oxide. Electromagnetic induction makes the particles form in a pattern if the signal is musical.

Question 16

How did the size and speed of the tape affect the sound quality?

Answer 16

Reduced high frequency response, prone to hiss and saturation.

Question 17

What does the capstan do on a cassette?

Answer 17

Controls speed of tape.

Question 18

What are the common tape lengths?

Answer 18

60/ 90/ 120 minutes.

Question 19

What are the three types of bands on a cassette?

Answer 19

Mono: 2 tracks (1 on each side)
Stereo: 4 tracks (2 on each side)
Multitrack: 4 tracks (tape plays one way)

Question 20

How was hiss reduced on cassette?

Answer 20

Dolby noise reduction.

Question 21

What is print through on a cassette?

Answer 21

Music is heard as an echo before it should play.

Question 22

What is degaussing?

Answer 22

Removing the build up of magnetism on tape head, reduces distortion and improves sound quality.

Question 23

What were the disadvantages of cassette?

Answer 23

Tapes could be snapped, tangled around the heads.

Difficult to cue/ locate tracks.

Question 24

What is tape bias?

Answer 24

Improves fidelity of tape.

Question 25

What is DC bias?

Answer 25

Addition of direct current to recorded audio signal.

Question 26

What is AC bias?

Answer 26

Addition of inaudible high frequency signal

Question 27

How does a higher tape bias affect the quality of a tape?

Answer 27

Better signal to noise ratio and sound quality.