The violin: music acoustics from baroque to romantic

246 Pages·2009·17.96 MB·English

by  Marcs Laboratories

The violin
music acoustics from Baroque to Romantic
John Ewan McLennan
ASTC (Dip. MET) 1947; Msc (UNSW) 1964; AIM, C. Eng.
in fulfilment
of the requirements for the degree
Doctor of Philosophy
School of Physics
The University of New South Wales
Sydney, Australia
August 2008
PLEASE TYPE
THE UNIVERSITY OF NEW SOUTH WALES
Thesis/Dissertation Sheet
Surname or Family name: McLennan
First name: John Other name/s: Ewan
Abbreviation for degree as given in the University
calendar: PhD
School: Physics Faculty: Science
Title: The violin: music acoustics from Baroque to
Romantic
Abstract 350 words maximum: (PLEASE TYPE)
A Baroque violin was initially made. It was then incrementally converted to a Romantic (modern) setup by
replacing the short neck with a longer, more slender neck and adding a longer ebony fingerboard, a heavier bassbar
and soundpost. This increased the total mass from 386 to 440 g. Several different Baroque and modern
configurations, with baroque and modern style bows, were used for acoustical measurements and playing tests with
professional violinists.
Chladni patterns were similar in both versions and also when the bridge was placed below the soundholes. The
Baroque version gave higher body mode frequencies than the Romantic. Placing the bridge below the soundholes
lowered the frequency of the 800 Hz resonance to 600 Hz.
Saunders Loudness Tests showed a response that varied strongly over the body resonances. For the transition from
Baroque to Romantic setup, hand bowing showed an increase of 1 dB and machine bowing about 5 dB.
The compliance of the body added to the air lowered the main air resonance by 5 Hz, equivalent to adding about
130 cc to the 2000 cc air volume.
The top plate stiffness measured at the bridge feet was about 10 kN/m higher at the treble foot than at the bass foot,
for all locations of the soundpost outside the treble foot. The stiffness at the bass foot remained constant. This was
reversed when the soundpost was placed between the two feet: the stiffness at the treble foot was then lower than at
the bass foot.
The rocking and bounce frequencies of the bridge were lowered from 3000 and 6000 Hz respectively to about 2.5
and 3 kHz when fitted to the violin. Thinning the bridge waist lowered the rocking frequency.
Recordings of performances on the violin were made for many combinations of physical state (baroque or
romantic), type of string and bow, position of bridge, and others. Long-term average spectra for these recordings are
compared here, and an online appendix includes these recordings in a way that allows them to be readily compared:
www.phys.unsw.edu.au/music/people/mclennanappendix.html
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I hereby grant to the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the
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rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation.
I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstracts International (this is applicable to doctoral theses only).
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Frontispiece: The violin of the study, from baroque to romantic.
ORIGINALITY STATEMENT
‘I hereby declare that this submission is my own work and to the best of
my knowledge it contains no materials previously published or written by
another person, or substantial proportions of material which have been
accepted for the award of any other degree or diploma at UNSW or any
other educational institution, except where due acknowledgement is made
in the thesis. Any contribution made to the research by others, with whom
I have worked at UNSW or elsewhere, is explicitly acknowledged in the
thesis. I also declare that the intellectual content of this thesis is the
product of my own work, except to the extent that assistance from others
in the project's design and conception or in style, presentation and
linguistic expression is acknowledged.’
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Date .................................................................
Acknowledgments
This work would not have proceeded without the encouragement and acute
mind of Professor Joe Wolfe and the computer skills and advice of
Professor John Smith. The able assistance of John Tann in the early stages
and Stefanie Orlik at the end has been greatly appreciated. A special
thankyou must go to André Almeida for assistance with editing the sound
samples. I am indebted to Professor John Smith for providing the program
for the LTAS used to analyse the sound files.
Neil Kilgour helped maintain the computers used for the experimental
work and word processing.
In addition to thanking those above, I thank my wife for her patience with
my virtual isolation over the period.
I also thank the four violinists, whom I am unable to name here because of
the University’s ethics policy.
CONTENTS
Chapter 1 INTRODUCTION 1
Chapter 2 THE VIOLIN:
Its ORIGINS, CONSTRUCTION and ADJUSTMENT 5
2.1 Early Development 7
2.2 Structural Changes 11
2.3 The Classical Method of Construction 13
2.4 The Location of the Bridge and Soundpost 15
2.5 Comparison of the Baroque and Romantid Violin 15
2.6 Scientific Violin Making 16
2.7 Violin Acoustics 17
2.8 Playing Considerations 18
2.9 Summary 19
2.10 References 19
Chapter 3 The ACOUSTICS of the VIOLIN 21
3.1 Introduction 21
3.2 The Bowed String 23
3.3 The Behaviour of the Bridge 27
3.4 The Behaviour of the Body 28
3.5 The Main Air Resonance 28
3.6 Free Plate Modes 29
3.7 Chladni Patterns28 31
3.8 Body Resonances 31
3.9 The Soundpost 36
3.10 The Soundholes 37
3.11 Damping in the Violin 37
3.12 Analysis of Violin Sounds 39
3.13 References 39
Chapter 4 BAROQUE VIOLIN CONSTRUCTION and CONVERSION to the
ROMANTIC SETUP (including properties of associated parts) 43
4.1 Introduction 43
4.2 Materials Used 43
4.3 Method of Construction 44
4.4 Fashioning the Violin Plates 48
4.5 The Properties of the Soundpost 54
4.6 The Measurement of String Tension 54
4.7 Strings Used for the Main Playing Tests 57
4.8 The Conversion from Baroque to Romantic Setup 60
4.9 Summary 64
4.10 References 67
Chapter 5 EXPERIMENTAL MEASUREMENT TECHNIQUES 68
5.1 Introduction 68
5.2 Determination of the Frequency Response 69
5.3 Initial Determination of Impact Bar mass and
Microphone position 71
5.4 A comparison of Input Admittance and
Sound Pressure Level Curves 73
5.5 Determination of Resonance Parameters 75
5.6 The Measurement of Effective Mass and Stiffness 81
5.7 Playing Tests 83
5.8 Effect of Sound Level Meter Weightings 84
5.9 Saunders Loudness Tests 84
5.10 The Measurement of Top Plate Stiffness 86
5.11 The Measurement of Bridge Resonance 89
5.12 References 90
5.13 Appendix: Derivation of equations for the Effective mass and 91
stiffness of a Resonance.
5.14 Addendum: The effect of Impact Bar mass and
Microphone position 92
Chapter 6 PLAYING TESTS on the BAROQUE and ROMANTIC VIOLIN 98
6.1 Introduction 98
6.2 Preliminary Playing Tests 99
6.3 Playing Tests the Neck Reset, a Higher Bridge and
heavier Gut Strings 104
6.4 Player Comment on Violin Performance 108
6.5 The Bridge below the Soundholes 109
6.6 Playing Tests on the Violin Converted to the Romantic
(modern) Setup 115
6.7 Player Comment on Violin with Romantic (modern) Setup 115
6.8 Saunders Loudness Tests on Romantic Setup 116
6.9 Playing Tests with Modern Setup and Thomastik Dominant
Strings 118
6.10 Player Comment using Thomastik Dominant Strings 120
6.11 Comparison of the Baroque and Romantic Versions of the
Same Violin 121
6.12 Comparison of the Playing Tests on the Two Forms 121
6.13 Discussion 124
6.14 References 127
6.15 Appendix: Playing Schedule 128
Chapter 7 RECORDINGS and PLAYER SUBJECTIVE ASSESSMENT
of the VIOLINS 129
7.1 Introduction 129
7.2 Player Assessment of the Violin 130
7.3 Acoustic Parameters Associated with the Two Versions 136
7.4 Played Sound Examples 138
7.5 References 141
7.6 Appendix: Sound Samples 141
Chapter 8 The BAROQUE VIOLIN: The EFFECT of BRIDGE and
SOUNDPOST POSITION 143
8.1 Introduction 143
8.2 The Violin Setup used in this Study 146
8.3 Experimental Procedure 148
8.4 Playing Tests 149
8.5 Tap Response 152
8.6 Characterisation of Peaks 157
8.7 The Main Air Resonance, A0 158
8.8 Main Body Resonances, B1- and B1+ 160
8.9 The 800 – 900 Hz Region 162
8.10 Stiffness measurements at the Bridge foot positions 164
8.11 Discussion 169
8.12 References 172
Chapter 9 EXPERIMENTS on the MAIN AIR RESONANCE, A0,
of the VIOLIN 173
9.1 Introduction 173
9.2 The Calculation of A0 175
9.3The Parameters of A0 176
9.4 The Purpose of this Study 177
9.5 Preliminary Measurements 178
9.6 The Helmholtz Resonance 178
9.7 The determination of the effective mass and stiffness of A0 181
9.8 Experiments increasing the Stiffness of the Violin 183
9.9 Experiments on Modified Soundholes 185
9.10 The Cremer Calculation of 2dL 186
9.11 Conclusion 188
9.12 References 189
9.13 Appendix: The calculation of the equivalent ellipse
for an f-hole 190
Chapter 10 BODY RESONANCE STUDIES 191
10.1 Introduction 191
10.2 Resonance Modes in the Baroque Setup 192
10.3 Resonance Modes for the Romantic Setup 194
10.4 The Effect of Neck/Scroll Mass and Chinrest
on Body Modes 195
10.5 Discussion 196
10.6 References 201
Chapter 11 VIOLIN BRIDGE RESONANCE STUDIES 202
11.1 Introduction 202
11.2 The Function of the Bridge 203
11.3 Naming the Parts of the Bridge 206
11.4 Bridge In-plane Resonance Measurements 207
11.5 Results on Bridges as First Fitted 208
11.6 The Result of Variation in the Waist 210
11.7 The Effect of Thinning the Other Ligaments 212
11.8 The Effect of reducing the mass 213
11.9 The Higher Resonance 213
11.10 Phase Studies at the Bridge Feet 216
11.11 Out of Plane Resonance 221
11.12 Discussion 223
11.13 Conclusion 224
11.14 References 225
11.15 Appendix: Example of raw data used in table 11.8 225
Chapter 12 CONCLUSIONS and SUGGESTIONS
for FURTHER WORK 228
12.1 Neck/Fingerboard Change 228
12.2 Saunders Loudness Tests 229
12.3 The Main Air Resonance 229
12.4 Body Compliance 230
12.5 The Soundhole Air Plug 230
12.6 Bridge Resonance 230
12.7 The Baroque to modern Transition 231
12.8 Comparison of Resonance Characteristics
of the two Versions 233
12.9 Suggestions for Further Work 234
12.10 Reference 236