Physics 1240 Tues 3/14/06Last time: SynthesisToday: Modular synthesis and Review for Exam IINext time: Exam II in-class Thurs 3/16Learning goals –1) understand modular synthesis2) do well on Exam II!Outline•Modular synthesis •Concept tests•ReviewLast timeSynthesis techniquesDigital samplingAdditive synthesis Subtractive synthesisAM and FMASDR envelopeCurrent technology: - digital synths- PC-based virtual synthsUse sampling + virtual analog synth (subtractive synthesis)Modular synthesisImportant modulesVoltage Controlled Oscillator (VCO) - voltage input Controls frequencyVoltage Controlled Amplifier (VCA) - voltage controlsVolumeASDR unit - gives the wave its transient shapeMoog modular synthesizerA) a waveform with an ASDR envelopeB) an amplitude modulated waveformC) a frequency modulated waveformD) none of the aboveCT17.1 The following modular synthesizer produces...Attack-Decay-Sustain-ReleaseASDR for plucked or hammered string e.g. guitar, piano sting not damped or mutedCT17.2 Does a piano or guitar have a sustain part of the ADSR envelope?A) yesB) noCT17.3 If you play your instrument in a small practice room then go into a large concert hall what will change?A) SustainB) ReleaseC) both A) and B)D) neither A) or B)question ambiguous, all answers given creditCT17.4 Two different instruments play the exact same note and hold it steady. However, they have different timbre. Why?A) They have a different harmonic series (f, 2f, 3f, ...)B) They appear as different points on the Fletcher-Munson diagramC) They have different frequency spectraD) The amplitudes of the harmonics are differentE) both C) and D)this sheet will be attached to your examExam II materialdBs (SIL) and W/m2(intensity)Intensity proportional to the square of amplitudeHuman Earouter-middle-innerAuditory canalOssicles (hammer, anvil, stirrup)cochleabasilar membranehair cellsoval window, round windowExam II material cont...LoudnessLoudness versus SIL and frequencyPhonsMajor scale WWHWWWHChromatic scale H x 12H = 1.05946W = 1.05946 x 1.05945Perfect 5th7 half-steps – ratio of 1.5Major 3rd4 half-steps – ratio of 1.26 (why is Pythagoras wrong?)Octave - ratio of 2Exam II material cont...Harmonic series – f, 2f, 3f, ...periodic = distinct pitch = harmonic seriesFrequency spectra – intensity versus frequencyTimbre = frequency spectra + transientssame harmonic series does not mean the same frequency spectra. why?Given a note is the 9thharmonic, what is the fundamental?Exam II material cont...Synthesisadditivesubractivedigital
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