Modal parameters of two violins with different varnish layers and subjective evaluation of their sound quality, Archives of Acoustics (original) (raw)

Modal Parameters of Two Violins with Different Varnish Layers and Subjective Evaluation of Their Sound Quality

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.

Modal parameters of two violins with different varnish layers and performance subjective evaluation of their sound quality

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 the subjects pointed out that the oil-varnished violin as better than the spirit-varnished instrument. Therefore it can be assumed with fairy great possibility that also in general, the oil-varnished violins sound somewhat batter than initially identical spirit-varnished ones.

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.

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).

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...

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.

Listener evaluations of violins made from composites

The Journal of the Acoustical Society of America, 2020

For centuries, wood, and more specifically spruce, has been the material of choice for violin top plates. Lately, carbon fiber instruments have entered the market. Some studies show that composite materials have potential advantages for making instruments (Damodaran A. et al. (2015)). However, no studies exist that evaluate violins made of different composite materials as judged by listeners. For this study, six prototype violins, differing only by the material of the top plate, were manufactured in a controlled laboratory setting. The six prototype violins were judged by experienced listeners in two double-blind experiments. In contrast to popular opinion that violins made from carbon have or lack a specific sound quality, the study provides insights in the diverse sounds and timbres violins from fiberreinforced polymers can create. It allows to investigate the links between the perception and the variations in material properties of the soundboards. Additionally, as neither players nor listeners are acquainted with these instruments, these results provide an interesting view on what type of qualities of violin-like sounds are preferred by listeners.

COMPARING THE SOUND O F GOLDEN AGE AND MODERN VIOLINS: LONG-TIME-AVERAGE SPECTRA

VSA Papers, 2005

Recordings of the sound spectra produced by violins made by Antonio Stradivari (1 5), Giuseppe Guameri del Gesu (1 5), and 18 contemporary makers were analyzed and compared In general, the sound produced by the 30 violins crafted by the two great Italian masters is very strong in the region from about C#q to G4 (274 to 41 0 Hz) and signij7cantly stronger in the highrfiequency regionfrom to G7 (2901 to 3073 Hz) and from B, to G#8 (3868 to 6494 Hz). The particular group of modem violins we analyzed had relatively equal or stronger fundamentals at very low notes below Cq (<260 Hz), in the mid-frequency region A4 to F, (440 to 2793 Hz), and at very high frequencies (>6.5 H z). Overall, the sound produced by the violins of Stradivari and Guameri was darker, less nasal, somewhat stronger in the high-brightness region, and possibly less sharp than was typical of the modem violins.