The Art and Science of Surround and Stereo Recording: Including 3D Audio Techniques

Preface
Contents
About the Author
Abbreviations
1 Spatial Hearing
1.1 Mechanisms of Localization
1.1.1 HRTF Phase-Characteristics
1.1.2 Localization and HRTFs
1.2 Mechanisms of Distance Perception
1.2.1 Sound Intensity
1.2.2 Diffuse Sound
1.2.3 Frequency Response
1.2.4 Binaural Differences
1.3 Spatial Impression
1.4 Physical Measures in Relation to Spatial Impression
1.5 The Influence of Loudspeaker Quality and Listening Room Acoustics on Listener Preference
1.6 Psychoacoustic Effects Concerning Localization and Spatial Impression with Loudspeaker Reproduction
1.6.1 Frequency-Dependent Localization Distortion in the Horizontal Plane
1.6.2 Frequency-Dependent Localization in the Vertical Plane
1.6.3 Effects Concerning the Reproduction of Spaciousness
References
2 Correlation and Coherence
2.1 Signal Correlation in Stereo Microphone Systems
2.2 Optimized Signal Coherence in Surround Microphone Systems
2.3 Optimized Interaural Correlation Coefficient
2.4 Evaluations Concerning the Interaction Between Loudspeaker Directivity and Listener Envelopment
2.5 Summary and Conclusion
2.6 Further Notice
References
3 Stereo Microphone Techniques
3.1 Coincident Techniques
3.1.1 XY with Cardioids and Hyper-cardioids
3.1.2 XY with Figure-of-Eights (Blumlein-Pair)
3.1.3 MS Stereo
3.1.4 Coincident Omni-directional Microphones?
3.1.5 BPT Microphone (‘Blumlein-Pfanzagl-Triple,’ BPT-3.0)
3.2 AB Pair Systems (Δt-Stereophony)
3.2.1 Small AB—Only a ‘Psychoacoustic Trick’?
3.2.2 Faulkner ‘Phased Array’
3.2.3 Faulkner ‘4-Way Phased Array’
3.2.4 Jecklin Disk—or Blumlein Disk? (… and Schneider Disk)
3.3 Equivalence Stereophony
3.3.1 ORTF
3.3.2 NOS
3.3.3 Large AB
3.3.4 Large AB—and the ‘Hole-in-the-Middle’ Effect
3.3.5 Small AB Versus Large AB: Introducing ‘medium AB’ and the ‘AB-Centerfill’ Technique
3.3.6 OCT—Optimal Cardioid Triangle
3.3.7 DHAB—Delayed Hemicardioid AB
3.3.8 SHAB—Side Hemicardioid AB
3.3.9 CHAB—Center Hemicardioid AB
3.4 Combined Stereo Microphone Techniques
3.4.1 The ‘AB-Polycardioid Centerfill’ (AB-PC)
3.4.2 ‘AB-Blumlein Centerfill’ and Other Techniques
References
4 Surround Microphone Techniques
4.1 Coincident and ‘Quasi-coincident’ Microphone Arrays
4.1.1 ‘Soundfield-’ or ‘Soundpoint-’ Microphone?
4.1.2 DMS (Double-MS Technique)
4.1.3 Double-MS + Artificial Head
4.1.4 BPT (Blumlein-Pfanzagl-Triple)
4.1.5 Martin Triple
4.1.6 XY Cardioid Arrangement (Back-to-Back)
4.1.7 MILAB 360 (360° Surround Microphone)
4.1.8 Phasor Arrays and the ‘Ghent’ Microphone
4.2 Spaced Arrays (Two-Dimensional Arrays)
4.2.1 Circular Microphone Array
4.2.2 Trinnov-Array
4.2.3 ABC 5 (Omni Array, Decca-Triangle)
4.2.4 INA 5 (Ideal Cardioid Arrangement)
4.2.5 OCT Surround (Optimal Cardioid Triangle—Surround)
4.2.6 OCT V.2
4.2.7 ORTF Surround
4.2.8 Klepko-Array
4.2.9 Atmo-Cross (IRT Cross)
4.2.10 Hamasaki Square
4.2.11 Multiple AB (‘Microphone Curtain’)
4.2.12 AB-PC (AB-Polycardioid Centerfill)
4.2.13 CHAB 5.0—Center Hemicardioid AB for Surround
4.2.14 Christensen Tree
4.2.15 Corey and Martin Tree
4.2.16 Fukada Tree
4.2.17 King-Tree
4.2.18 Polyhymnia Pentagon
4.2.19 Ron Streicher’s Surround Sound Decca-Tree
4.2.20 XY Tri (by Andrew Levine)
4.3 Baffle and 3D Techniques
4.3.1 KFM 360 (‘Kugelflächenmikrofon’)
4.3.2 Various Baffled Surround Microphone Systems
4.3.3 Holophone ‘H2-Pro’ and ‘PortaMic 5.1’
4.3.4 DPA—‘D:Mension 5100’ Mobile Surround Microphone
4.3.5 Sony Sphere-Arrangement
4.3.6 Multichannel Microphone Array (Johnston-Lam)
4.3.7 HOA—Higher-Order Ambisonics: The ‘Eigenmike®’, Octomic and ZM-1
4.3.8 OSIS-System (Optimal Sound Image Space—‘Jecklin Surround’)
4.3.9 Pan-Ambiophonic 2D/3D System
4.3.10 BACCH(™) 3D Sound
4.4 ‘3D’ or ‘Immersive Audio’
4.4.1 Auro 3D
4.4.2 Dolby Atmos
4.4.3 3D Audio: Psychoacoustic Considerations and Comparative Tests
4.5 General Thoughts on Microphone Arrays
4.6 Conclusion
References
5 Artificial Head Recordings
5.1 Use of an Artificial Head as a ‘Human Reference’
5.2 Studies Concerning the Quality of Artificial Heads
5.3 Summary and Conclusion Concerning the Studies of Artificial Heads
References
6 Some Thoughts on Subjective Listening Tests
6.1 Basic Considerations Concerning Listening Tests
6.2 Requirements for the Reproduction System; Consideration of Qualitative Parameters
6.3 Further Factors Influencing Listener Perception
6.4 Selection of Appropriate Sound Attributes
6.5 A Few Thoughts on ‘Calibrating’ Test Listeners and ANOVA
6.6 Recording of Program Material for 5.1 Surround at the Salzburg Festival Hall
6.6.1 Program Material and Venue Acoustics for the Orchestral Recording Listening Test
6.6.2 Program Material and Venue Acoustics for the Duo Recording Listening Test
6.7 Subjective Listening Test with 5.1 Surround Loudspeaker Reproduction
6.7.1 Listening Test ORCHestral Recording in 5.1 Surround
6.7.2 Listening Test DUO Recording in 5.1 Surround
6.7.3 Duration of the Orchestral and DUO Listening Tests and Listening Room Acoustics
6.8 Subjective Listening Test (Binaural) with Headphone Reproduction
6.8.1 Choice of Headphones for the Binaural Listening Test
6.9 Analysis of the Listening Tests
6.9.1 Statistical Analysis of the Orchestral Recording ‘5.1 Surround’ Listening Test
6.9.2 Statistical Analysis of the Orchestral Recording ‘binaural’ Listening Test
6.9.3 Comparison of the Analysis Results ‘ORCH 5.1’ and ‘ORCH Binaural’
6.9.4 Statistical Analysis of the DUO Recording ‘5.1 Surround’ Listening Test
6.10 Correlation Analysis of the Listening Test Data
References
7 Analysis of Frequency-Dependent Signal Correlation and Coherence in Surround Microphone Systems
7.1 Measurement of the Frequency-Dependent Cross-Correlation (FCC) and Frequency-Dependent Inter-aural Cross-Correlation (FIACC)
7.2 Measurement of the Frequency-Dependent Signal Coherence
7.3 Pair-wise Analysis of Correlation and Coherence with Surround Microphone Signals
7.4 Conclusions
7.4.1 Thoughts on Diffuse-Field Correlation (DFC)
References
8 Analysis of Frequency-Dependent Signal Cross-correlation (FCC) in Stereo Microphone Systems
8.1 Calculation of the ‘Critical Frequency’ in Small AB Microphone Systems
8.2 Calculation of the ‘Out-of-Phase Maximum Frequency’
8.3 Comparison of the FCC and FIACC of Various Stereophonic Microphone Techniques
8.4 Conclusions, Further Analysis and Literature
References
9 Discussion and Conclusion: An Attempt at a Qualitative Ranking of Stereo and Surround Microphone Techniques—An Examination of Various Studies in the Field
9.1 Stereo Microphone Techniques
9.1.1 Coincident XY with Cardioids and Hyper-cardioids
9.1.2 Coincident XY with Figure-of-Eights (Blumlein-Pair)
9.1.3 Small Versus Large AB—Revisited
9.1.4 Microphone Technique, Reverberation Radius and Frequency-Dependent Radiation Patterns of Musical Instruments
9.1.5 Ranking of a Few of the Most Common Stereo Main Microphone Techniques
9.2 Surround Microphone Techniques
9.2.1 Comparative Surround Microphone Tests
9.2.2 A Final Ranking for Several Common 5.1 Surround Microphone Techniques
References
10 Binaural Quality Index of Reproduced Music (BQIrep)
10.1 Conclusion
References
11 A Short History of Microphone Techniques and a Few Case Studies
11.1 The Early Beginnings of ‘Stereophonic Sound’
11.2 DECCA-tree
11.3 RCA ‘Living Stereo’ Recordings
11.4 MERCURY ‘Living Presence’
11.5 A Few Case Studies of Live and Studio Recordings with Orchestra (and Solo-Instruments)
11.6 Solo-Piano Microphone Techniques
11.7 Studio Ensemble Recordings with Acoustic Instruments
11.8 Work Practice Recommendations
References
Appendix A
Appendix B Reference-Email No. 1 Concerning OCT-Surround (by Cornelius van der Gragt)
Reference-Email No. 2 Concerning OCT-Surround (by Jan Korte)
Appendix C The MAAT “2BC multiCORR” Cross-Correlation Meter Plug-In
Index