1. 88727359 Multimedia Production
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Audio/Sound

2. สารบัญ Introduction Types of Microphones Mic Placement and Selection
Audio Problems: Distortion and Noise
Audio Compression
Sound Perspectives
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3. Introduction
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4. Introduction Quality audio is extremely important in media production
Poor-quality sounds can destroy the impact of high quality visuals
High-quality sounds affect emotions and develop additional creative dimensions and responses
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5. Introduction THE POWER OF MUSIC IN FILM - How music affects film
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6. Types of Microphones
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7. Types of Microphones
Mics convert analog sound wave action into analog fluctuations in electrical voltage
A digital signal must be created by converting the analog signal through an analog-to-digital converter
for recording, processing, and maintenance of the highest quality during duplication
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8. Types of Microphones Transducer Elements Dynamic mic consists of
a moving coil attached to a vibrating diaphragm or disc suspended between two magnetic poles
As the diaphragm vibrates with the sound wave, the coil moves up and down within a magnetic field and changes the voltage of the electrical current flowing through the coil
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9. Types of Microphones
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10. Types of Microphones Ribbon mic contains
a narrow strip of corrugated foil suspended in a magnetic field
This ribbon vibrates in response to the difference in air pressure in front and in back of it and produces an alternating current along the length of a coil
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11. Types of Microphones
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12. Types of Microphones Condenser mics consist of
a capacitor that requires two charged plates: a diaphragm and a fixed back plate.
As the diaphragm vibrates, the space between it and the fixed plate changes in capacitance, that is, in its ability to pass an electrical current or signal
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13. Types of Microphones
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14. Types of Microphones
Pickup Patterns
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15. Types of Microphones Impedance
two basic impedance choices, high or low
High-impedance mics are low-cost amateur mics, may be connected with wires that contain one conductor and a shield, which does not provide the maximum protection for the signal from outside interference
Low-impedance mics normally are connected with wires that contain two conductors and a shield, providing maximum protection for the signal
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16. Mic Placement and Selection
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17. Mic Placement and Selection
On-camera mics, such as a reporter’s handheld mic, are visible to the viewer.
Hand mics are the most common on-camera mics
generally has a relatively wide pickup pattern, such as omnidirectional or cardioid
keep the hand mic at a relatively constant distance, loudness relatively constant
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18. Mic Placement and Selection
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19. Mic Placement and Selection
A lavaliere mic is either hung around the performer’s neck with a strap or clipped to a tie or outer garment
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20. Mic Placement and Selection
Off-camera mics are not visible to the viewer.
Off-camera mics may be attached to a mic boom.
A mic boom is a long pole that can be placed (usually above the heads of the talent) just outside the camera frame.
It can also be hidden on the set.
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21. Mic Placement and Selection
There are three different types of mic booms: fishpole, giraffe, and perambulator booms.
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22. Mic Placement and SelectionAL
ให้นิสิตค้นรูป Mic Booms ทั้ง 3 ประเภท
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23. Mic Placement and Selection
Selecting the Best Mic
The more versatile and widely used mics are the dynamic and electret condenser cardioids.
They have extremely durable elements and a pickup pattern
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24. Mic Placement and Selection
Selecting the Best Mic
A cardioid mic works best when it is relatively close to the speaker or sound source
A lavaliere condenser mic can be the size of a tie tack. It can be placed very close to the speaker without dominating the frame. It can also be completely hidden in a person’s clothing
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25. Mic Placement and Selection
Selecting the Best Mic
The ribbon mic is best left to completely stationary performance situations, such as talk shows, interviews, or dramatic radio productions.
An omnidirectional dynamic or condenser mic is often used to record several speakers simultaneously.
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26. Audio Problems: Distortion and Noise
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27. Audio Problems: Distortion and Noise
Distortion is an unwanted change in a signal
Noise is an unwanted addition to the signal
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28. Audio Problems: Distortion and Noise
Most common type of distortion
loudness distortion, which occurs when a sound is recorded at a level that exceeds the limitations of the electronic system
Loudness distortion is controlled by setting the volume so that it does not exceed the limits of the system
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29. Audio Problems: Distortion and Noise
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30. Audio Problems: Distortion and Noise
Two types of noise, ambient noise, and system noise.
Ambient noise comes from open mics fed into an audio console or tape recorder that pick up the sound of air ventilators, lights, cameras, or other devices.
System noise can come from the electrical recording system and equipment.
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31. Audio Problems: Distortion and Noise
An important determinant of sound quality is a system’s signal-to-noise ratio.
This is the ratio of desired sounds to unwanted system noise. Many professional audio systems have signal-to-noise ratios of 55:1 or above
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32. Audio Problems: Distortion and Noise
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33. Audio Problems: Distortion and Noise
White noise
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34. Audio Compression
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35. Audio Compression
refers to a reduction in the amount of bandwidth required to record or transmit a digital signal.
A compression system omits certain sounds unimportant or redundant in the overall signal so that the human ear does not recognize the loss.
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36. Audio Compression
In lossy systems, unneeded data are not transmitted or recorded. Tests indicate the deleted data generally are not missed.
Lossless systems either do not compress the files or do so in such a manner that the deleted data are replaced or substituted for when decompressed
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37. Audio Compression
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38. Audio Compression
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39. Sound Perspectives
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40. Sound Perspectives
The relationship of sound to space parallels that of a picture with three dimensions:
left-right, up-down, and in front of or behind the listener
The direction of the sound can only be determined through the use of one of several multichannel systems to give the audience the sense that the sound is to the left, right, in front of, or behind.
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41. Sound Perspectives Stereo Sound
Stereo and surround-sound systems and modifications are attempts to duplicate the three-dimensional aspects of a sound environment
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42. Sound Perspectives Multichannel Sound
Surround sound was the next logical step from stereo in creating the realistic three dimensional sound environment.
Mixing the sound into at least four channels  four corners of the listening space
increases the complexity of mic placement, mixing, and speaker location
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43. Sound Perspectives Dolby Digital 5.1, 6.1, and 7.1 Sound and Beyond
designed to complement advanced television systems requires six, seven, or eight channels of audio and six or seven separate speakers.
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44. Sound Perspectives ถ้าวางลำโพงแบบ Dolby 7.1 จะวางอย่างไร AL
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45. Sound Perspectives
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46. คำถาม
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