Questions and Problems

Author: N.H. Crowhurst

1. What kinds of storage medium can be used for audio recording? Name

some uses for recording other than high fidelity.

2. What two basic ways are there of recording on discs? How does the problem of making a cutter and pickup for disc recording compare with that of making a loudspeaker and microphone?

3. What kinds of transducer element can be used for a phonograph pickup? Indicate which ones use velocity and which the amplitude principle.

4. Even though velocity recording is the basic form, why do modern recordings deviate so as to approximate nearer to constant amplitude? What turnover frequencies are useEJor this transition?

5. What is the best way to demagnetize tape or wire completely, preparatory to recording on it, and why?

6. Explain how ultrasonic bias works to improve the quality of magnetic recording.

7. Discuss the basis for equalizer requirements in magnetic recording.

8. How does optical recording work?

9. What is acoustic feedback? Besides the well-known case of a loudspeaker feeding back to a microphone in a public address system, where else can this phenomenon cause trouble?

10. Explain why a loudspeaker needs electrical damping from the amplifier that drives it. What limitations are there to this method of damping? Describe an experiment that demonstrates this.

11. Explain why a recording made with a high quality microphone placed in a typical audience seat would be very disappointing. What ideology of recording or high fidelity does this fact disprove?

12. Explain the physiology of hearing on which this difference between direct hearing and attempts to reproduce the original depends.

13. What is binaural reproduction? How should it be listened to, and what happens if such a recording is played over a more conventional system?

14. Research into the stereophonic nature of sound reveals what important facts? How can the best illustion of realism be achieved?