1. ACOUSTIC
1.1. No Recodring
1.2. Musical Instruments
2. ANALOG
2.1. Microphone - Electrical current
2.2. Pitch, Tone, Speed locked together
2.3. Record, Amplify and Edit Sound
2.4. SIGNAL PATH
3. DIGITAL
3.1. Analog Signal Converted to Numbers
3.2. Alter Speed, Tone and Pitch Independently
4. HOW DO WE HEAR?
4.1. Physical -Ears
4.1.1. Vibration of hairs in the ear
4.1.2. Human hearing range - decreases with age
4.1.3. Average person's hearing capacity is from 20 HZ to 20,000 HZ
4.2. Subconscious
4.2.1. McGurk Effect
4.2.2. Hear words and understand their meaning
4.2.3. Sight can influence perception of sound
4.3. Conscious
4.3.1. Brain processes and makes meaning of what we hear
5. SOUND SPEED
5.1. Air - Sound travels the slowest
5.2. Water - Sound travels 4 times faster
5.3. Solid - Sound travels 15 times faster
6. TIME
6.1. Represent time taken for one complete cycle of vibration to pass a given point.
6.1.1. As the frequency of a wave increases, the time period of the wave decreases
6.2. Comb Filtering
7. PHASE
7.1. Timing Difference
7.1.1. location or timing of a point within a wave cycle of a repetitive waveform
8. FREQUENCY
8.1. Rate at which sound waves fluctuate
8.2. Measured in HZ
8.3. Sine Wave - One Frequency at a time
8.4. Sometimes referred to as Pitch
8.5. Timbre
8.5.1. The difference between quality of tone from one's voice or musical instrument.
8.6. Lower Frequency
8.7. Higher Frequency
8.7.1. More detail in shape of sound wave
9. AMPLITUDE
9.1. Measured in Decibels - dB
9.1.1. Sound Pressure Level (SPL)
9.2. Measure how intensely sound waves fluctuate
9.3. A high amplitude wave carries a large amount of energy
9.4. A low amplitude wave carries a small amount of energy
10. ACOUSTIC SIGNAL PATH
10.1. ACOUSTIC SOUND IS PRODUCED
10.1.1. Vocals - someone singing
10.1.2. A Musical Instrument
10.1.3. No Recodring
11. SIGNAL PATH
11.1. ACOUSTIC TO ANALOG AND BACK TO ACOUSTIC SIGNAL PATH
11.1.1. Acoustic Sound Source
11.1.1.1. Transducer
11.1.1.1.1. Input Mixer/Pre Amplifier
11.1.1.1.2. Dynamic microphone
11.1.1.1.3. Electric Guitar PickUps
11.1.1.1.4. Change Acoustic sound waves into an analog electrical signal
11.1.1.1.5. Piezoelectric Elements
11.1.1.1.6. Sound is altered depending on Proximity Effect
11.1.1.1.7. Higher signal to noise ratio - cleaner sound
11.2. ACOUSTIC SOUND TO RECORDING DEVICE
11.2.1. Acoustic Sound Source
11.2.1.1. Mic Level Signal
11.2.1.1.1. Input Mixer/ Preamplifier
11.2.2. Analog Connections
11.2.2.1. Mic Level Electrical Analog Signal
11.2.2.1.1. Weakest - very low voltage
11.2.2.2. Line Level Signal - less than one volt
11.2.2.2.1. Boosted Mic Level Signal - Preamplifier
11.2.2.2.2. Found in studios
11.2.2.3. Speaker level - 100 volts
11.2.2.3.1. Live Sound Production
11.2.2.4. Two wires
11.2.2.4.1. Signal
11.2.2.4.2. Ground
11.2.2.5. Mic cables
11.2.2.5.1. Balanced cables
11.3. GAIN STAGES IN ANALOG DOMAIN
11.3.1. Any point at which a signal can change volume
11.3.2. Signal passes through Amplifier and Attenuator
11.3.3. Microphone signal through mixer - 3 or 4 gain stages
11.3.4. Setting volumes in Signal path - GAIN STAGING/ SETTING GAIN STRUCTURE
11.3.5. Turn down Input Signal - Amplifier produces undistorted output
11.3.6. DO NOT turn input sound so low- avoid noise
11.3.7. Clean Signal - High Signal to Noise Ratio
11.3.7.1. Relatively quiet noise and relatively loud signal
11.3.7.2. Use Level Meter
11.3.7.2.1. Use a VU (Volume Units) Meter
11.3.7.3. Use Peak Meter
11.3.7.3.1. Shows highest instantaneous level the sound hits
11.3.7.3.2. Faster response to transience
11.3.7.4. Use 0 dB reference point
11.3.7.4.1. dB Sound Pressure Level (SPL)
11.4. DIGITAL SIGNAL PATH
11.4.1. Analog to Digital
11.4.1.1. Sampling
11.4.1.1.1. ADC - Analog to Digital Converter
11.4.1.1.2. Sampling Rate or Sampling Frequency
11.4.1.1.3. Most Common 44, 100 samples per second or 44.1 kilohertz
11.4.1.1.4. Nyquist Frequency - up to 1/2 of the sampling rate can be recorded
11.4.1.2. Filter out all frequencies above the Nyquist limit
11.4.1.2.1. Anti-aliasing Filter
11.4.1.3. Higher frequencies may cause Aliasing
11.4.2. Gain Stage
11.4.2.1. Sound too loud
11.4.2.1.1. Run out of number range if turn sound too loud
11.4.2.1.2. Finite number of Quatizing
11.4.2.2. 0 dB FS - Using all available Quantizing levels available
11.4.2.3. Signal too low
11.4.2.3.1. Quantization distortion
11.4.2.4. Dither
11.4.2.4.1. Allows digital domain to handle low sounds - low amplitude signals
11.4.2.4.2. Eliminates Quantization Distortion
11.4.2.4.3. Use it
12. DIGITAL AUDIO WORKSTATION
12.1. REVERB CHAMBER
12.2. MIXING CONSOLE
12.3. TAPE RECORDER
12.4. MIDI SEQUENCER
12.5. MIDI
12.5.1. Language
12.5.1.1. Pitch Bend
12.5.1.2. Note off
12.5.1.3. Note On
12.5.2. Instructions on how to make sound
12.5.3. Medium
12.5.4. USB Midi Interface
12.5.5. Input -Electronic Instrument played by a person
12.6. DRUM MACHINE
12.7. SYNTHESIZER
12.8. GUITAR AMPLIFIER
12.9. EFFECTS UNIT
12.10. COMPUTER
13. MIXING SOUND
13.1. SPECTRUM ANALYZER
13.1.1. 1000 Hz - Sine Wave
13.1.1.1. Frequency
13.1.1.1.1. Partials
13.1.1.2. Sine waves at different amplitudes, frequencies, timings
13.1.2. Tells which parts of Frequency Spectrums are at what amplitude
13.2. COMPRESSION
13.2.1. Dynamic Processor
13.2.1.1. Time Parameters
13.2.1.2. Types
13.2.1.2.1. Compressor
13.2.1.2.2. Limiter
13.2.1.2.3. Expander
13.2.1.2.4. Gate
13.3. MONITORS LEVELS
13.3.1. Check Levels at different volume
14. How to turn digital audio into finished product
14.1. MIXING AND EFFECTS PROCESSING
14.1.1. Effects
14.1.2. Volume Levels
14.1.2.1. Your ears determine the best levels
14.1.2.1.1. Avoid Clipping Distortion
14.1.2.2. What needs to be quieter?
14.1.2.3. Good gain staging practices
14.1.3. Equalization
14.1.3.1. Uses Filters/ Adjusts Frequencies
14.1.4. Automation
14.1.4.1. Computer moves faders
14.1.4.2. Controls the mix
14.1.5. Panning
14.1.5.1. Left, Right, In-between, Panaroma
14.1.5.1.1. Bass Management - Panning Sound
14.1.5.2. One ear compatibility
14.1.5.3. Mono compatibility
14.1.5.4. Individual tracks recorded
14.1.5.5. Mono and Panned to create stereo mix