Acoustical measurements of a rabab reconstructed after a pictorial source from the 13th century (Cantigas de Santa María)

Instrument: rabab Pictorial source: Cantigas de Santa Maria, E-Codex (Códice de los músicos), ca. 1284, fol. 118r, Cantiga 110, Madrid, San Lorenzo de El Escorial, Real Biblioteca del Monasterio del Escorial, Ms. b-I-2 Instrument maker: Thilo Hirsch Year of manufacture: 2021 Location: Basel, property of the ensemble arcimboldo
Dimensions: Total length: 468 mm Max. Body width: 104 mm Body depth: approx. 80 mm
Vibrating string lengths: a-string: 403 mm d-string: 401 mm
Materials: Body: cherry Pegbox: cherry Fingerboard: maple Bars: spruce Nut/String attachment button: bone Bridge: maple Top: goatskin
The main aim of this research was to measure the acoustic effects of the different sound holes. To do this, the instrument was first measured with the two open rosettes on the fingerboard and then the upper one was sealed with a piece of wood (see photos of the setup).
Acoustical measurements: Alexander Mayer, mdw - University of Music and Performing Arts Vienna, Department of Music Acoustics – Wiener Klangstil (IWK), 25.9.2023
Force: Impact hammer exciting at the bass side of the bridge ACC: Acceleration measured on the same side, close to the impact point. Average is the average of all measurements (to be used in the analysis).
Photos of the setup: Thilo Hirsch
Folder cantigas_rosette_o_offen: Files: cantigas_roo_1 to 6  (Description: upper rosette open) File: cantigas_roo_do (Description: upper rosette open / damper moved between 2 rosettes)    
Folder cantigas_rosette_o_zu: Files: cantigas_roz_1 to 6 (Description: upper rosette closed with wooden sheet)
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How to read VIA-Files: Line 1 to 9: Header, Line 8 holds the number of values
Data is organized as followed: 1st col: Frequency [Hz], 2nd col: Magnitude [as Factor not dB!], 3rd col: Phase [rad]    4th col:  Real part [as Factor not dB!] 5th col: Imaginary part [as Factor not dB!]. So only first 3 columns are needed
To get dB Value: Amplitude[dB] = 20 log [Magnitude]
Usually the Magnitude was calculated as response/reference (input) in the frequency domain. As for measuring the mechanical admittance the sensor is most likely an accelerometer (capturing the response in m/s2 of the object of interest) and the reference an impact hammer capturing the input force in Newton. As the mechanical admittance is defined as v/F (speed over force) the acceleration signal has to be integrated. The here captured signals are integrated in the frequency domain, what means the magnitude is divided by the corresponding frequency value in s-1. 
Values coded like: 3.30750000000000E+1 -> 3.3075 * 10 -> 33.075