Transcript Physics 1251 The Science and Technology of Musical Sound
Physics 1251 The Science and Technology of Musical Sound
Unit 4 Session 37 MWF Synthesizers
Physics 1251 Unit 4 Session 37
Synthesizers • • • • •
In your own words, describe what a synthesizer is and what it does.
A synthesizer: is an electronic device; is controlled by a player; produces electro-acoustic signals; simulates acoustic instruments; generates novel and unique sounds.
Physics 1251 Unit 4 Session 37
Synthesizers • • • • • 1′ Lecture: A Synthesizer is a player-controlled electronic device creating electro-acoustical signals that emulate other instruments or generate unique sounds.
Notes played by acoustic instruments pass through four phases: (1) attack, (2) decay; (3) sustain; (4) release. (ADSR) Realistic synthesis requires sound to change with time in pitch, frequency recipe, and amplitude during the ADSR phases.
Synthesizers are either analog or digital.
Synthesizers employ either additive (or subtractive) synthesis or frequency modulation (FM).
Physics 1251 Unit 4 Session 37
Synthesizers 80/20 A Synthesizer is a player-controlled electronic device creating electro acoustical signals that emulate other instruments or generate unique sounds.
What does that mean?
Physics 1251 Unit 4 Session 37
Synthesizers 80/20 A Synthesizer is a player-controlled electronic device creating electro acoustical signals that emulate other instruments or generate unique sounds.
Synthesizer
4 4
♩ ♩ ♩ ♩ ♩ ♩ ♩ ♩
Physics 1251 Unit 4 Session 37
Synthesizers 80/20 A Synthesizer is a player-controlled electronic device creating electro acoustical signals that emulate other instruments or generate unique sounds.
Synthesizer Current I Voltage V I =V/R Ohm’s Law: R =V/I
Physics 1251 Unit 4 Session 37
Synthesizers 80/20 A Synthesizer is a player-controlled electronic device creating electro acoustical signals that emulate other instruments or generate unique sounds.
Synthesizer Current + - + -+ Voltage
Physics 1251 Unit 4 Session 37
Synthesizers 80/20 A Synthesizer is a player-controlled electronic device creating electro acoustical signals that emulate other instruments or generate unique sounds .
Synthesis or the Real Thing?
Physics 1251
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Unit 4 Session 37
Synthesizers The first modern synthesizer was produced by RCA in 1955.
The Moog (rhymes with vogue) synthesizer was invented in 1965 by Robert Moog.
First Moog Synthesizer
Physics 1251 Unit 4 Session 37
Synthesizers ♪ Realistic synthesis requires emulation of realistic musical sounds.
80/20 Musical sounds are characterized by four phases: (1) attack; (2) decay; (3) sustain; (4) release; abbreviated ADSR.
Attack Decay Sustain Release Envelop
Physics 1251 Unit 4 Session 37
Synthesizers Synthesizers use analog or digital processing.
Analog Sound Waves
Physics 1251 Unit 4 Session 37
Synthesizers 80/20 Synthesizers use analog or digital processing.
Sound Waves 1000 0100 0010 0001 80/20 The amplitude of the waveform is digitized and expressed as a binary number.
Physics 1251 Unit 4 Session 37
Synthesizers
Digital to Analog Conversion (DAC)
1 2 0001 0010 4 0100 DAC (Concept) 8 1000
Physics 1251 Unit 4 Session 37
Synthesizers
Electronic Digital-to-Analog Conversion
Input Number Output Voltage
Physics 1251 Unit 4 Session 37
Synthesizers
Electronic Digital-to-Analog Conversion
Input Number Output Voltage
Physics 1251 Unit 4 Session 37
Synthesizers
Electronic Digital-to-Analog Conversion
Input Number Output Voltage
Physics 1251 Unit 4 Session 37
Synthesizers •
Additive Synthesis:
The output signal is built up from a sum of harmonic signals
.
Σ
Physics 1251 Unit 4 Session 37
Synthesizers •
Frequency Modulation (FM) Synthesis:
In FM Synthesis the frequency f o of the signal is modulated up and down with a frequency f FM . The vibration recipe contains peaks at f o ∓ n f FM .
f o If f FM = f o , then one produces a harmonic series, f = m f o .
f FM Voltage Controlled Oscillator (VCO)
Physics 1251 Unit 4 Session 37
Synthesizers • • • • • Summary: A Synthesizer is a player-controlled electronic device creating electro-acoustical signals that emulate other instruments or generate unique sounds.
Notes played by acoustic instruments pass through four phases: (1) attack, (2) decay; (3) sustain; (4) release. (ADSR) Realistic synthesis requires sound to change with time in pitch, frequency recipe, and amplitude during the ADSR phases.
Synthesizers are either analog or digital.
Synthesizers employ either additive (or subtractive) synthesis or frequency modulation (FM).