Acknowledgements
Introduction
Chapter 1: Sound Production vs. Sound Reproduction
- Live Classical Musical Performances
- Live Popular Music Performances
- Reproduced Sound - The Audio Industry
- Preserving the Art - The Circle of Confusion
- Music and Movies - the State of Affairs
- The Role of Loudspeakers and Rooms
- Human Adaptation, a Reality the Cannot be Ignored
- Human Suggestibility
Chapter 2: A Scientific Perspective on Audio
- Requirements for Scientific Investigations
Chapter 3: Subjective Measurements - Turning Opinion into Fact
- Is Blind Listening Necessary?
- Hearing Ability and Listener Performance
- Stress and Strain
- How Many Channels?
- Controlling the Variables in Subjective Evaluations
- Controlling the Physical Variables
- The Listening Room - Making Tests Blind
- Real-time Loudspeaker Comparison Methods
- Binaural Record/Replay Loudspeaker Comparisons
- Listener Position and Seating
- Relative Loudness
- Absolute Loudness - Playback Sound Levels
- Choosing Program Material
- Power Amplifiers, Wire and So Forth
- Controlling the Psychological Variables
- How to do the Test
- Is it preference or accuracy that is evaluated?
- Chapter 4: The Perceptual and Physical Dimensions of Sound
- The Frequency Domain
- The Amplitude Domain
- Amplitude and Frequency Together: Frequency Response
- Amplitude and Frequency Together: Equal-Loudness Contours
- Loudness Controls and Tone Controls - Do They Work, Are They necessary?
- The Boundaries of What We Can Hear
- What Is Acceptable Background Noise?
- Linear Distortions: Amplitute and Phase vs. Frequency
- Spectral Tilt
- Resonances Viewed in Frequency and Time
- Finding and Fixing Resonances
- A Persistent Problem: Differentiating Between Evidence of Resonances and Acoustical Interference
- Critical bands, ERBNs, and the resolution of the hearing system
- Amplitude, Frequency and Time Together: Waterfall Diagrams
- Phase and Polarity - Do We Hear Waveforms?
- The Audibility of Phase Shift and Group Delay
- Phase Shift at Low Frequencies: a Special Case
- The Audibility of Absolute Polarity
- Non-Linear Distortions
- Wavelength, the Key to Understanding Much in Audio
- Loudspeaker Directivity
- Room Resonance Basics
- Resistive/Porous Absorbers and Membrane/Diaphragmatic Absorbers
- Diffusers and Other Sound Scattering Devices
Chapter 5: Characterizing Loudspeakers - Can We Describe What is Good?
- The Wisdom of the Ancients
- Identifying the Important Variables - What do we Measure?
- Anechoic Measurements - the Spinorama Evolves
- Total Sound Power as a Measured Parameter
- Why do we measure what we do? Are there better ways?
- Predicting Room curves From Anechoic Data - An Exercise in curve Matching.
- A Message About Sound Absorption and Scattering
- Why Do We Care About Room Curves?
- Closing the Loop Predicting Listener Preferences From Measurements
- The Olive Experiments - Part One
- The Olive Experiments - Part Two
- The Olive Experiments - Part Three
- Loudspeaker Resonances - Detection and Remedies
- Summary and Discussion
Chapter 6: Loudspeaker/Room Systems - an Introduction
- One Room, Two Sound Fields - The Transition Frequency
- A Brief History of Loudspeaker/Room Interactions
- Timbral and Spatial Effects Attributable to Rooms
Chapter 7: Above the Transition Frequency: Acoustical Events and Perceptions
- The Physical Variables: Early Reflections
- Problems with the Stereo Phantom Center Image
- The Physical Variables: Loudspeaker Directivity
- The Physical Variables: Acoustical Surface Treatments
- Absorbers
- Engineered Surfaces and Other Sound Scattering/Diffusing Devices
- Subjective Evaluations of Physical Variations
- Side Wall Treatment: Reflecting or Absorbing -Kishinaga et al. (1979)
- The Effect of Loudspeaker Directivity - Toole (1985)
- Loudspeaker Directivity and Wall Treatment Together - Choisel (2005)
- The Nature of the Sound Field - Klippel (1990)
- Observations of an Audio Enthusiast - Linkwitz (2007)
- Observations of an Audio Enthusiast - Toole (2016)
- Floor Reflections: A Special Case?
- Professional vs. Recreational Listening
- Hearing Loss is a Major Concern
- Discussion
- Perceptual Effects of Room Reflections
- Adaptation and Perceptual Streaming
- The Effect of Rooms on Loudspeaker Sound Quality
- The Effect of Rooms on Speech Intelligibility
- Sound Localization in Reflective Spaces The Precedence (Haas) Effect
- Bringing the Precedence Effect into the Real Acoustical World
- Ceiling vs. Wall Reflections
- Real vs. Phantom Images
- Speech vs. Various Musical Sounds
- Meaningful Measurements of Reflection Amplitudes
Chapter 8: Below the Transition Frequency: Acoustical Events and Perceptions
- The Basics of Room Resonances and Standing Waves
- Optimizing Room Dimensions - Does an Ideal Room Exist?
- Are Non-Rectangular Rooms the Answer?
- Solutions for the Real World
- Deliver Energy to the Modes and Dissipate Some of That Energy with Absorbers
- Deliver Energy to the Modes and Reduce the Coupling of That Energy to the Listener By Optimizing the Listening Location - Positional Equalization
- Reduce the Energy Delivered to a Bothersome Mode by Optimizing the Loudspeaker/Subwoofer Location
- Reduce the Energy Delivered to a Bothersome Mode by Using Parametric Equalization
- Reduce the Energy Delivered to a Bothersome Mode by Using Simple Mode-Manipulation Techniques
- Selective Mode Activation in Rectangular Rooms Using Passive Multiple-Subwoofer Mode Manipulation
- Mode Manipulation for Rectangular Rooms Using Multiple Subwoofers and Signal Processing
- Mode Manipulation For Any Room Using Multiple Subwoofers and Signal Processing: Sound Field Management (SFM).
- Revisiting Room Resonances in Time and Space
- Do we Hear the Spectral Bump, the Temporal Ringing, or Both?
- Stereo Bass: Little Ado About Even Less
- Bass Management Makes it all Possible.
- Summary and discussion
Chapter 9: Adjacent boundary and loudspeaker mounting effects
- The effects of solid angles on the radiation of sound by omnidirectional sources
- Classic adjacent-boundary effects
- Alleviating adjacent-boundary effects
- Loudspeaker mounting options and effects
- An example of adjacent-boundary interference
- Boundary-friendly loudspeaker designs
- Array loudspeakers - other ways to manipulate boundary interactions
- Listeners also have boundaries
Chapter 10: The Sound Fields in Sound Reproduction Spaces
- Reverberation
- Measuring reverberation time
- Calculating reverberation time
- Is there a more useful metric for our purposes?
- Diffusion
- Direct sound and early reflections
- Near and far fields of rooms sound level vs. distance
- Near and far fields of sound sources
- Point sources and real loudspeakers
- Line sources
- Air absorption at high frequencies
- Screen loss in home theaters and cinemas
- The directivities of common sound sources
Chapter 11: Sound in cinemas
- The closed loop of cinema sound
- Sound fields in cinemas
- A loudspeaker in a cinema
- Adding a screen and applying the X-curve
- The origins of the X-curve
- A recent study adds confirmation and clarity
- Flat, direct sound is an enduring favorite
- Alternative targets - is it time to move on?
- Compatibility with the rest of the audio world
- Compatability with the cinema world
- The effects of room size and seats
- Cinema sound - where to next
Chapter 12: Sound in home listening rooms, home theaters and recording control rooms
- Good sound starts with good loudspeakers
- Typical loudspeaker specifications - part of the problem
- Loudspeakers in small rooms: the meaning of room curves
- The effect of loudspeaker directional configuration
- Looking back 42 years: the Moller/Bruel and Kjaer experiments
- Room curves and equalization
- Subjective preferences for sound spectra in listening rooms
- Dialog intelligibility in home theaters
- Recording control rooms
- Old-school monitoring
- Modern monitoring
Chapter 13: A rational approach to designing, measuring and calibrating sound reproducing systems
- Low frequencies - the universal problem
- Sound above the transition frequency
- Thirty years - some things change, some don't
- The wrong room curve target?
- Room correction and room equalization are misnomers.
- Automotive audio
- Headphones
- Cinemas
- Is there a common factor - a generalizable target?
Chapter 14: Measurement methods
- Alternative views of frequency response
- Prediction of the direct sound and room curves from anechoic data
- In-situ measurement of the direct sound
- The steady-state room curve
- Measures of loudness and system level calibrations.
- Evaluating relative program loudness levels
- Multichannel system level calibration
- The effect of propagation distance - a side-channel challenge
- Measurement microphones
Chapter 15: Multichannel Audio
- A few definitions
- The birth of multichannel audio
- Stereo - an important beginning
- Loudspeakers as stereo image stabilizers
- Quadraphonics - stereo times two
- Multichannel audio - cinema to the rescue
- Multichannel comes home
- THX embellishments
- How many loudspeakers and where?
- Optimizing the delivery of envelopment
- Summary
- Surround system layouts
- Loudspeaker directivity requirements
- Mission oriented acoustical treatments
- Surround loudspeaker options
- The Ambisonics alternative
- Upmixer manipulations: creative instincts at work
- Multichannel audio goes digital, discrete and compressed
- Three-dimensional sound - immersive audio
- The perception of elevation
Chapter 16: Loudspeakers and Power Amplifiers
- Consequence of Loudspeaker Impedance Variations
- The Damping Factor Deception
- Loudspeaker Sensitivity Ratings and Power Amplifiers
- The Audibility of Clipping
Chapter 17: Hearing loss and hearing conservation
- Occupational noise exposure limits
- Non-occupational noise exposure
- Binaural hearing is also affected
- Some obsession can be a good thing
Chapter 18: Fifty years of progress in loudspeaker design
- My introduction to the real world
- Two decades of domestic loudspeakers
- Some early professional monitor loudspeakers
- A Toole monitor loudspeaker
- Looking around and looking ahead
- The end
References
Index