Answers
(You can find more questions at http://www.cwc.ac.uk/sound)
Answers to the questions at the end of Chapter 1
1. |
c. |
16–16 000 Hz |
2. |
b. |
340 m/s |
3. |
c. |
Above roughly 700 Hz |
Answers to the questions at the end of Chapter 2
1. |
b. |
Two sound pressures e. Two powers |
2. |
c. |
400 Hz |
3. |
c. |
100 Hz |
Answers to the questions at the end of Chapter 3
1. |
b. |
A minimum of vibration |
2. |
c. |
60 dB |
3. |
b. |
0.5 s |
4. |
a. |
1 square metre of 100% absorber |
Answers to the questions at the end of Chapter 4, Part 1
1. |
b. |
They are generally robust and reliable, and |
|
c. |
The quality of their output, while good, is likely to be inferior to some other types |
2. |
a. |
They are usually fragile, and |
|
b. |
Very good quality is possible because of the lightness of the ribbon |
3. |
c. |
It is like two spheres in contact |
4. |
b. |
25–30 dB |
5. |
c. |
45° on each side of the rear |
Answers to the questions at the end of Chapter 4, Part 2
1. |
b. |
Standard three-core microphone cable |
2. |
d. |
Electrostatic (but personal microphones are powered by batteries) |
Answers to the questions at the end of Chapter 5
1. |
b, c and d (all except omnidirectional) |
2. |
b. Looking at the instrument in the same direction that an audience would do |
Answers to the questions at the end of Chapter 6, Part 1
1. |
c. |
Average signal voltages |
2. |
d. |
Peak signal voltages |
3. |
c. |
1–2 seconds |
Answers to the questions at the end of Chapter 6, Part 2
1. |
b. |
6 |
2. |
c. |
1–2% |
Answers to the questions at the end of Chapter 7, Part 1
1. |
d. |
1 ms |
2. |
b. |
Microphones too widely spaced |
3. |
a. |
Fully right |
4. |
a. |
An out-of-phase condition |
Answers to the questions at the end of Chapter 7, Part 2
1. |
c. 180° |
2. |
b. 135° |
3. |
a. 90° |
4. |
Coincident omni microphones do not give stereo! |
5. |
c. Figures of eight (d is a silly answer!) |
Answers to the questions at the end of Chapter 8, Part 1
1. |
c. |
To allow the fader to be set to an optimum position |
2. |
b. |
φ indicates a phase reverse control |
Answers to the questions at the end of Chapter 8, Part 2
1. |
a. |
With XLR sockets in the studio (a microphone with XLR connectors has a PLUG on it) |
2. |
d. |
Accurate 0.775 V, about 1 kHz (sometimes the frequency is an accurate 1 kHz, but it is the voltage which MUST be accurate) |
Answers to the questions at the end of Chapter 9
1. |
c. |
The input rises 3 dB for each 1 dB rise in the output above the threshold |
2. |
c. |
20:1 or more |
Answers to the questions at the end of Chapter 10, Part 1
1. |
a. |
44 000 (44 100 to be precise) |
2. |
c. |
9 |
3. |
d. |
Musical Instrument Digital Interface |
Answers to the questions at the end of Chapter 11, Part 1
1. |
d. |
Erase, record, replay |
2. |
a. |
4.75 cm/s |
3. |
a. |
Reduced high frequencies |
Answers to the questions at the end of Chapter 12
1. |
a. |
Wide horizontally, narrow vertically |
2. |
c. |
Cardioid |
Answers to the questions at the end of Chapter 14
1. |
c. |
13 A. The mixer would probably take only about 3 A normally but there could be a surge when switching on |
2. |
c. |
About 75° |
3. |
d. |
Reject is probably the best answer, but circumstances might not allow this, in which case the next best answer is c – open it up and wipe it dry as far as possible. Then put it in a warm place for a few hours before inspecting it for signs of moisture |
4. |
b. |
Black |