Modal parameters of two violins with different varnish layers and performance subjective evaluation of their sound quality (original) (raw)
Related papers
Archives of Acoustics, 2013
Two violins were investigated. The only intentionally introduced difference between them was the type of varnish. One of the instruments was covered with a spirit varnish, the other was oil varnished. Experimental modal analysis was done for unvarnished/varnished violins and a questionnaire inquiry on the instrument's sound quality was performed. The aim of both examinations was to find differences and similarities between the two instruments in the objective (modal parameters) and subjective domain (subjective evaluation of sound quality). In the modal analysis, three strongly radiating signature modes were taken into account. Varnishing did not change the sequence of mode shapes. Modal frequencies A0 and B(1+) were not changed by oil varnishing compared to the unvarnished condition. For the oil varnished instrument, the frequency of mode B(1+) was lower than that of the same mode of the spirit varnished instrument. Our two violins were not excellent instruments, but before varnishing they were practically identical. However, after varnishing it appeared that the oil-varnished violin was better than the spirit-varnished instrument. Therefore, it can be assumed with a fairly high probability that also in general, the oil-varnished violins sound somewhat better than initially identical spirit-varnished ones.
Archives of Acoustics, 2013
Two violins were investigated. The only intentionally introduced difference between them was the type of varnish. One of the instruments was covered with a spirit varnish, the other was oil varnished. Experimental modal analysis was done for unvarnished/varnished violins and a questionnaire inquiry on the instrument's sound quality was performed. The aim of both examinations was to find differences and similarities between the two instruments in the objective (modal parameters) and subjective domain (subjective evaluation of sound quality). In the modal analysis, three strongly radiating signature modes were taken into account. Varnishing did not change the sequence of mode shapes. Modal frequencies A0 and B(1+) were not changed by oil varnishing compared to the unvarnished condition. For the oil varnished instrument, the frequency of mode B(1+) was lower than that of the same mode of the spirit varnished instrument. Our two violins were not excellent instruments, but before varnishing they were practically identical. However, after varnishing it appeared that the oil-varnished violin was better than the spirit-varnished instrument. Therefore, it can be assumed with a fairly high probability that also in general, the oil-varnished violins sound somewhat better than initially identical spirit-varnished ones.
Influence of a Violin Tailpiece Material on Acoustic Properties of a Violin
The different mechanical properties of the materials from which the tailpieces are made have a noticeable effect on the acoustic performance of the violin. These elements are made today from ebony, rosewood, boxwood, aluminium, or plastic. The aim of this study was to check the exact impact of tailpieces made of different materials on the frequency response function (FRF) of a violin's bridge and the timbre of the instrument's sound. For this purpose, the bridge FRF measurement was carried out, and a psychoacoustic test was conducted. The material from which the tailpiece is made to the greatest extent affects the modal frequencies in the range 530-610 Hz (mode B1+), which mainly manifested itself in a change in the instrument's timbre in terms of the brightness factor. The study showed that the lighter the tailpiece, the darker the sound of the violin. It was also revealed that the selection of accessories affects factors such as openness, thickness, and overall quality of the sound.
Experimental Modal Analysis of Violins Made from Composites
The 18th International Conference on Experimental Mechanics, 2018
Six prototype violins made from composite materials are made and investigated using experimental modal analysis with the roving hammer method. The average FRF’s obtained show an influence of the materials on the vibrational response up to 2200 Hz. The A0 breathing mode and B1- mode are identified and are found to be significantly lower than in classical wooden violins. Additional measurements with a Laser Doppler Vibrometer and shaker found the same modes with a small difference in frequency (3–8 Hz).
Experimental Characterization of Oil-Colophony Varnishes: Protection of Musical Instruments
2016
Historically, the varnishes had the aim to protect the bowed musical instruments by the external agents and to confer them an aesthetic value. During the 17 th and 18 th century, in Italy, the bowed instruments, especially violins, were generally covered by a layer of varnish made with several natural materials such resins, oil or hide glue: i.e., instruments by the great violin maker Antonio Stradivari were covered often with a layer of varnish made of linseed oil and colophony in the ratio 3:1, respectively. The main aim of this work was to study the modifications that occur in those kinds of varnishes, after exposing them to some factors of degradation. In order to study the different properties of organic coatings and their suitable compositions, different mixtures of linseed oil and colophony were recreated in the laboratory following an ancient recipe: linseed oil and colophony were mixed together with different ratios (50/50 and 75/25, respectively) and then, they were applied on Maple wood samples and on glass slides for experimental purposes. In order to investigate the different external factors which cause the varnish layer degradation, samples were analyzed by different techniques before and after different ageing processes (thermo-hygrometric cycles, exposition to UV lamp and to acid vapors). Out of strong experimental evaluation, all the results suggested that the composition of 75/25 (oil: colophony) is much better as a varnish for musical instruments.
Wooden music instrument vibro-acoustic fingerprint: the case of a contemporary violin
2023
Violins are complex wooden musical instruments, whose quality is mainly evaluated on the basis of their aesthetics, as well as depending on the historical relevance of their makers. However their acoustic quality remains a key evaluation parameter for performers and listeners. The instrument perceived quality, in turn, depends, on one side, on the player, the environmental conditions and on the listeners' psychoacoustic factors. On the other side, the quality of a violin depends on its materials, constructive and setup parameters, that impact on the vibro-acoustical characteristics of the instrument. This work investigates a procedure for the vibro-acoustic characterization of a violin, here called vibro-acoustic fingerprint, as an example of vibro-acoustical characterization of a wooden music instrument. The procedure was applied, as a case study, to an Italian contemporary violin, built in the year 2011 by the violin-maker Enzo Cena on a Guarneri del Gesù model.
Bridge admittance measurements of 10 preference-rated violins
Proceedings of the Acoustics 2012 Nantes Conference , 2012
The overall goal of the research presented here is to investigate correlations between measured vibrational properties of the violin and subjective judgments by violinists and to better understand what distinguishes one instrument from another. The novelty of this study is that 10 violins of different make and age were evaluated and preferencerated by 13 experienced musicians in a carefully controlled violin-playing perceptual experiment. Regarding the vibrational properties of the instruments, the classical bridge admittance measurements have been examined so far. The five "signature" modes below 600 Hz were identified in all of the tested violins. Comparisons between violin groups based on across-players average preference score generally showed no prominent preference-related trends for mode frequencies or frequency spacings. Further analysis showed no links between admittance correlations and preference.
Physical and Chemical Properties of Varnishes and Their Vibrational Consequences
2002
It is well known that the sound quality of stringed instruments evolves for years after their fabrication, specially during the varnish drying process. Even if essentially aesthetic and protective, the varnish has an effect on the vibrating properties of the instrument. This may be due to the evolution of its chemical structure and mechanical behaviour. The existing studies on the matter are not really concluding. From viscoelastic characterisations, we will try to understand on a simplified system what the relationship is between the physico-chemical properties of isolated simple varnishes and the mechanical characteristics of samples of varnished woods.
Modal analysis of violin bodies with back plates made of different wood species
BioResources, 2020
This research investigated the potential of some European wood species for use in the manufacturing of the back plates of violins as an alternative to the quite rare curly maple wood. An experimental modal analysis was employed for this purpose using the impact hammer method. The modal analysis was performed both on the top and back plates, as individual structures, and then after being integrated into the violin body. The modal analysis envisaged the determination of the eigenfrequencies (natural frequencies), the number of spectral components, and the quality factor, as important indicators of the acoustic performances of a musical instrument. A multi-criteria analysis based on the values obtained for these indicators allowed interesting findings concerning the acoustic properties of the selected wood species (hornbeam, willow, ash, bird-eye maple, walnut, and poplar). Same as curly maple, they all have special aesthetics, but only hornbeam, willow, and ash wood proved to have aco...