Lecture Notes: Basics of Audio Engineering

Introduction

• Speaker: Danzig Leonie
• Focus on basic terminology and definitions crucial for audio engineering
• Aim: Avoid ignorance in the industry by mastering foundational knowledge

Definition of Sound

• Sound: The brain's interpretation of an auditory stimulus
  • Sound pressure waves travel through the air
  • These waves hit the eardrum and are interpreted by the brain
  • Example: A tree falling in a forest does not make sound unless perceived by a brain

Understanding Sound Waves

• Sine Wave: A pure, simple waveform
• Amplitude:
  • Relates to volume
  • Measured in decibels (dB - lowercase 'd', uppercase 'B')
  • Named after Alexander Graham Bell

Sound as Electricity

• Sound is comparable to electrical voltage, traveling through air (oxygen)
• Compression and Rarefaction:
  • Positive voltage: Compression
  • Negative voltage: Rarefaction

Sound Pressure Levels (SPL)

• SPL measured in decibels
• Examples of decibel levels:
  • 10 dB: Rustling leaves
  • 50-60 dB: Normal conversation
  • 70-80 dB: Toilet flushing/vacuum cleaner
  • 120-130 dB: Live rock band
  • 180 dB: Rocket launch
• Safety Note: High decibels can cause permanent hearing damage

Waveform Characteristics

• 360 Cycle: A wave completes a 360-degree cycle forming a circle
  • One full cycle is known as a wavelength
  • Frequency: Cycles per second (Hz)
    • Measured in Hertz (Hz - lowercase 'h', uppercase 'z')
    • Human hearing range: 20 Hz to 20,000 Hz (20 kHz)

Frequency Demonstration

• Using a ProTools signal generator to demonstrate frequency
• Lower frequencies are more omnidirectional
• Higher frequencies are more unidirectional

Directionality of Sound

• Low frequencies: Omnidirectional (e.g., bass heard from a distance)
• High frequencies: Unidirectional (e.g., sibilance blocked by obstacles)

Key Waveform Characteristics

• Amplitude: Measured in decibels, relates to volume
• Frequency: Measured in Hertz, relates to pitch

Practical Application: Creating an 808 Kick Drum

• Sidechain Technique:
  • Using a kick drum and a signal generator
  • Utilize gates and sidechaining to create the "808 kick drum" effect
  • Adjust frequency and gate settings for desired sound

Conclusion

• Importance of fundamental understanding in audio engineering
• Encouragement to continue learning and subscribe for more tutorials

These notes capture the fundamental principles of audio engineering, offering insights on sound definition, waveforms, SPL, and practical studio techniques. Remember to subscribe to the channel for further learning!