88727359 Multimedia Production บทที่ 7 Audio/Sound

สารบัญ Introduction Types of Microphones Mic Placement and Selection Audio Problems: Distortion and Noise Audio Compression Sound Perspectives บทที่ 7 Audio/Sound

Introduction บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Introduction THE POWER OF MUSIC IN FILM - How music affects film บทที่ 7 Audio/Sound

Types of Microphones บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Types of Microphones บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Types of Microphones บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Types of Microphones บทที่ 7 Audio/Sound

Types of Microphones Pickup Patterns บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Mic Placement and Selection บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Mic Placement and Selection บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

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. บทที่ 7 Audio/Sound

Mic Placement and Selection There are three different types of mic booms: fishpole, giraffe, and perambulator booms. บทที่ 7 Audio/Sound

Mic Placement and Selection AL ให้นิสิตค้นรูป Mic Booms ทั้ง 3 ประเภท บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

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. บทที่ 7 Audio/Sound

Audio Problems: Distortion and Noise บทที่ 7 Audio/Sound

Audio Problems: Distortion and Noise Distortion is an unwanted change in a signal Noise is an unwanted addition to the signal บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Audio Problems: Distortion and Noise https://www.youtube.com/watch?v=4UfwO5x4Cwk บทที่ 7 Audio/Sound

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. บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Audio Problems: Distortion and Noise บทที่ 7 Audio/Sound

Audio Problems: Distortion and Noise White noise https://www.youtube.com/watch?v=TYIxwr3jCO8 บทที่ 7 Audio/Sound

Audio Compression บทที่ 7 Audio/Sound

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. บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

Audio Compression บทที่ 7 Audio/Sound

Audio Compression บทที่ 7 Audio/Sound

Sound Perspectives บทที่ 7 Audio/Sound

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. บทที่ 7 Audio/Sound

Sound Perspectives Stereo Sound Stereo and surround-sound systems and modifications are attempts to duplicate the three-dimensional aspects of a sound environment https://www.youtube.com/watch?v=J1bv42kHmqA บทที่ 7 Audio/Sound

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 บทที่ 7 Audio/Sound

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. บทที่ 7 Audio/Sound

Sound Perspectives ถ้าวางลำโพงแบบ Dolby 7.1 จะวางอย่างไร AL บทที่ 7 Audio/Sound

Sound Perspectives บทที่ 7 Audio/Sound

คำถาม บทที่ 7 Audio/Sound