Post on 30-Dec-2015
Physics 1251Physics 1251The Science and The Science and
Technology of Musical Technology of Musical SoundSound
Physics 1251Physics 1251The Science and The Science and
Technology of Musical Technology of Musical SoundSound
Unit 4Unit 4
Session 37 MWFSession 37 MWF
SynthesizersSynthesizers
Unit 4Unit 4
Session 37 MWFSession 37 MWF
SynthesizersSynthesizers
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
In your own words, describe what a In your own words, describe what a synthesizer is and what it does.synthesizer is and what it does.
A synthesizer:A synthesizer:• is an electronic device;is an electronic device;• is controlled by a player;is controlled by a player;• produces electro-acoustic produces electro-acoustic signals;signals;• simulates acoustic simulates acoustic instruments;instruments;• generates novel and unique generates novel and unique sounds.sounds.
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
11′ Lecture:′ Lecture:
• A Synthesizer is a player-controlled electronic A Synthesizer is a player-controlled electronic device creating electro-acoustical signals that device creating electro-acoustical signals that emulate other instruments or generate unique emulate other instruments or generate unique sounds.sounds.
• Notes played by acoustic instruments pass through Notes played by acoustic instruments pass through four phases: (1) attack, (2) decay; (3) sustain; four phases: (1) attack, (2) decay; (3) sustain; (4) release. (ADSR)(4) release. (ADSR)
• Realistic synthesis requires sound to change with Realistic synthesis requires sound to change with time in pitch, frequency recipe, and amplitude time in pitch, frequency recipe, and amplitude during the ADSR phases.during the ADSR phases.
• Synthesizers are either analog or digital.Synthesizers are either analog or digital.• Synthesizers employ either additive (or Synthesizers employ either additive (or
subtractive) synthesis or frequency modulation subtractive) synthesis or frequency modulation (FM).(FM).
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
80/2080/20A Synthesizer is a player-controlled A Synthesizer is a player-controlled electronic device creating electro-electronic device creating electro-acoustical signals that emulate other acoustical signals that emulate other instruments or generate unique instruments or generate unique sounds.sounds.
What does that mean?What does that mean?
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
80/2080/20A Synthesizer is a A Synthesizer is a player-controlledplayer-controlled electronic device creating electro-electronic device creating electro-acoustical signals that emulate other acoustical signals that emulate other instruments or generate unique instruments or generate unique sounds.sounds.
SynthesizerSynthesizer
4444 ♩♩♩♩♩♩ ♩♩ ♩♩♩♩ ♩♩
♩♩
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
80/2080/20A Synthesizer is a player-controlled A Synthesizer is a player-controlled electronic deviceelectronic device creating electro- creating electro-acoustical signals that emulate other acoustical signals that emulate other instruments or generate unique instruments or generate unique sounds.sounds.
SynthesizerSynthesizer
Voltage VVoltage V
Current ICurrent I
I =V/RI =V/R
Ohm’s Law: R Ohm’s Law: R =V/I=V/I
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
80/2080/20A Synthesizer is a player-controlled A Synthesizer is a player-controlled electronic device creating electronic device creating electro-electro-acoustical signalsacoustical signals that emulate other that emulate other instruments or generate unique instruments or generate unique sounds.sounds.
CurrentCurrentSynthesizerSynthesizer
VoltagVoltagee
++
--++
--++
-- ++
--
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
80/2080/20A Synthesizer is a player-controlled A Synthesizer is a player-controlled electronic device creating electro-electronic device creating electro-acoustical signals that acoustical signals that emulate other emulate other instruments or generate unique instruments or generate unique soundssounds..Synthesis or the Real Synthesis or the Real Thing?Thing?
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
♪ The first modern synthesizer The first modern synthesizer was produced by RCA in 1955.was produced by RCA in 1955.
♪ The Moog (rhymes with vogue) The Moog (rhymes with vogue) synthesizer was invented in synthesizer was invented in 1965 by Robert Moog.1965 by Robert Moog.
First Moog SynthesizerFirst Moog Synthesizer
AttackAttack
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 Synthesizers Synthesizers
♪♪Realistic synthesis requires emulation of Realistic synthesis requires emulation of realistic musical sounds.realistic musical sounds.
80/2080/20Musical sounds are characterized by Musical sounds are characterized by four phases: (1) attack; (2) decay; (3) four phases: (1) attack; (2) decay; (3) sustain;sustain;(4) release; abbreviated ADSR.(4) release; abbreviated ADSR.
DecayDecay SustainSustain ReleasReleasee
EnvelopEnvelop
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 Synthesizers Synthesizers
80/2080/20Synthesizers use analog or digital Synthesizers use analog or digital processing.processing.
AnaloAnalogg
80/2080/20Synthesizers use analog or digital Synthesizers use analog or digital processing.processing.
Sound Sound WavesWaves
Pre
ssu
reP
ressu
re
Volt
aV
olt
ag
eg
e
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 Synthesizers Synthesizers
DigitDigitalal
80/2080/20Synthesizers use analog or digital Synthesizers use analog or digital processing.processing.
Sound Sound WavesWaves
Pre
ssu
reP
ressu
re
Digital:Digital:
10001000010001000010001000010001
80/2080/20The amplitude of The amplitude of the waveform is the waveform is digitized and digitized and expressed as a binary expressed as a binary number.number.
Digital to Analog Conversion (DAC)Digital to Analog Conversion (DAC)
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
000000110010010001001000
10010000
10110100
11
22
44
88
DAC DAC (Concept)(Concept)1101101100100111
Electronic Digital-to-Analog Electronic Digital-to-Analog ConversionConversion1 1 0 1 1 0
001 1 1 1 1 1 001 1 1 1 1 1 111 0 0 1 0 0 111 1 1 1 1 1 001 0 0 1 0 0 110 1 1 0 1 1 000 0 0 0 0 0 000 0 0 0 0 0 110 0 1 0 0 1 111 1 0 1 1 0 000 1 1 0 1 1 000 0 1 0 0 1 110 0 0 0 0 0 110 0 0 0 0 0 00
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
Input Input NumberNumber
Output VoltageOutput Voltage
Electronic Digital-to-Analog Electronic Digital-to-Analog ConversionConversion1 1 0 1 1 0
001 1 1 1 1 1 001 1 1 1 1 1 111 0 0 1 0 0 111 1 1 1 1 1 001 0 0 1 0 0 110 1 1 0 1 1 000 0 0 0 0 0 000 0 0 0 0 0 110 0 1 0 0 1 111 1 0 1 1 0 000 1 1 0 1 1 000 0 1 0 0 1 110 0 0 0 0 0 110 0 0 0 0 0 00
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
Input Input NumberNumber
Output VoltageOutput Voltage
Electronic Digital-to-Analog Electronic Digital-to-Analog ConversionConversion1 1 0 1 1 0
001 1 1 1 1 1 001 1 1 1 1 1 111 0 0 1 0 0 111 1 1 1 1 1 001 0 0 1 0 0 110 1 1 0 1 1 000 0 0 0 0 0 000 0 0 0 0 0 110 0 1 0 0 1 111 1 0 1 1 0 000 1 1 0 1 1 000 0 1 0 0 1 110 0 0 0 0 0 110 0 0 0 0 0 00
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
Input Input NumberNumber
Output VoltageOutput Voltage
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
Additive Synthesis:Additive Synthesis:• The output signal is built up from a sum The output signal is built up from a sum
of harmonic signalsof harmonic signals..
ΣΣ
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
Frequency Modulation (FM) Frequency Modulation (FM) Synthesis:Synthesis:
• In FM Synthesis the frequency fIn FM Synthesis the frequency foo of of the signal is modulated up and down the signal is modulated up and down with a frequency fwith a frequency fFM FM . The vibration . The vibration recipe contains peaks at recipe contains peaks at ffoo ∓ n f∓ n fFM FM ..
If fIf fFMFM = f = foo , then one , then one produces a harmonic produces a harmonic series, f = m fseries, f = m foo . .
Voltage Voltage Controlled Controlled Oscillator Oscillator (VCO)(VCO)
ffFMFM
ffoo
Physics 1251Physics 1251 Unit 4 Session 37Unit 4 Session 37 SynthesizersSynthesizers
Summary:Summary:• A Synthesizer is a player-controlled electronic A Synthesizer is a player-controlled electronic
device creating electro-acoustical signals that device creating electro-acoustical signals that emulate other instruments or generate unique emulate other instruments or generate unique sounds.sounds.
• Notes played by acoustic instruments pass Notes played by acoustic instruments pass through four phases: (1) attack, (2) decay; (3) through four phases: (1) attack, (2) decay; (3) sustain; sustain; (4) release. (ADSR)(4) release. (ADSR)
• Realistic synthesis requires sound to change with Realistic synthesis requires sound to change with time in pitch, frequency recipe, and amplitude time in pitch, frequency recipe, and amplitude during the ADSR phases.during the ADSR phases.
• Synthesizers are either analog or digital.Synthesizers are either analog or digital.• Synthesizers employ either additive (or Synthesizers employ either additive (or
subtractive) synthesis or frequency modulation subtractive) synthesis or frequency modulation (FM).(FM).