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BASIC AUDIO SYSTEM 2 Pre- Amplifier (Voltage Amp.) Pre- Amplifier (Voltage Amp.) Power Amplifier Mic Speaker
Mono System 3
BASIC AUDIO SYSTEM (mono) 4 Amplifier Mic Speaker
Stereo Amplifier 5 Amplifier MicSpeaker Amplifier Left Channel Right Channel
Stereo amplifier becomes Hi-Fi S/N ratio better than 50 db Freq. response should be flat within +/- 1db Non linear distortion not more than 1% System should possess dynamic range atleast 80 db (20db to 100 db) Stereophonic effect should be provided Environmental conditions to eliminate external noise in listening room High fidility can be achieved by using low noise components & proper design of circuits Reflections, reverberations,ambient noise also affect fidility 6
Specification or characterstics of Hi-Fi Amplifier Gain Bandwith Impedance Distortion -Frequency -Phase -Amplitude -Self Oscillation 7
Hi-Fi Amplifier 8
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Controls in Hi-Fi amplifier Balance control (to match both ch) Blend Control (to dilute stereo effect) Master gain control (overall volume) Loudness control (dominant bass boosting with low boosting at treble, background music) Bass and treble controls Quasi –stereo switch (mono) Mic in, Aux in,Earphone in 10
PA system 11
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13 PA system
14 Tone Controls
15 Tone Controls
16 Tone Controls
Special Tone Controls Parametric Equalizer Graphic Equalizer 17
Parametric Equalizer 18
Parametric Equalizer 19
Proportional- or Variable-Q
Adjustable Filters Can be quite fancy, e.g. a graphic equalizer Gain of individual frequency channels adjustable for the ultimate listening experience BUT – still has to be adjusted by hand
22 Graphic Equalizer
23 Graphic Equalizer
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Fundamentals of Audio Production Chapter 9 25 Graphic equalizers
Graphic Equalizer 26
27 Graphic Equalizer
28 Dolby System
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30 Dolby System
31 Dolby System
32 Dolby System
33 Dolby System
Loudspeakers and Speaker Systems Basic Categories –Woofer: Low frequency, htz. –Mid-Range: Middle of audible range, ,000 htz. –Tweeter: high frequency speakers, 1,000-20,000 htz.
How a speaker works
Speaker Cabinets Finite Baffle Enclosure –“Cabinet design that absorbs sound wave produced by reward excursion of the speaker cone.” Base-Reflex Enclosure –Designed with a port to channel reflected base through cabinet. Ducted Port Enclosure –Designed with a tube set into a port that is tuned to a specific frequency range.
Speaker Systems Cross-Over Network –Electronic system to split and channel the frequency ranges to specific speakers within a system. –Small overlap between ranges to smooth transitions between speakers.
38 Crossover network
39 Crossover network
40 Crossover network
41 Crossover network
42 Crossover network