A collection of bowed responses of cello strings (part 7)

This dataset contains time-domain recordings of bowed cello strings, acquired to construct Schelleng diagrams for the analysis of steady-state vibrational response. It is the first of eight parts forming the complete collection of bowed responses.

The measurements were performed using a robotic bowing apparatus consisting of a UR5e robotic arm mounted on a monochord setup with rigid terminations. Cello G2 strings with a nominal pitch of 98 Hz were used. All signals were sampled at 50 kHz. The bowing parameters span a relative bow-bridge distance β from 0.02 to 0.2 and a bow force Fb from 0.1 to 4 N. Parts 7 and 8 extend the bow force range to 4–12 N, exceeding typical playing conditions, with a reduced β range of 0.02 to 0.07.

Each measurement corresponds to a single point on the Schelleng diagram. The data are organised into folders named by measurement index. Each folder contains subfolders numbered 1 to 3, corresponding to different steady bow speeds: folder 1 contains recordings at vb = 0.1 m/s, folder 2 at vb = 0.05 m/s, and folder 3 at vb = 0.2 m/s.

Each subfolder contains three files: a betas.csv file specifying the relative bow-bridge distance β, a timestamps file indicating the start and end of the classification window used for regime identification, and a whole.csv file containing the time-domain signals. The whole.csv file includes four columns: bow force in N, bow velocity in m/s, bridge force in N, and nut force in N.

Four string types were tested, each defined by a unique combination of core and winding materials: type A has a steel core with tungsten winding; type B has a stranded steel core with tungsten/silver winding; type C has a nylon core with silver winding; type D has a steel core with nickel winding. Two tension groups were used: T1 with lower nominal operating tension and T2 with higher tension. Different samples of the same string type were tested to evaluate variability across strings from the same batch. Setup variability was assessed by repeating the Schelleng diagram measurements twice under the same conditions.

The complete collection is organised as follows:

• Part 1: String types A, B, C, sample #1, tension T1 (10.5281/zenodo.17749110)
• Part 2: String type D sample #1; string type A samples #2 and #3, tension T1 (10.5281/zenodo.17782542)
• Part 3: String type A sample #4; string type D sample #2; string type A sample #1 cold and warm, tension T1 (10.5281/zenodo.17782552)
• Part 4: String types A, B, C, sample #1, tension T2 (10.5281/zenodo.17782565)
• Part 5: String type D sample #1; string type B sample #2, tension T2 (10.5281/zenodo.17782538)
• Part 6: Setup variability, two repeated Schelleng diagrams (10.5281/zenodo.17795326)
• Part 7: Extended bow force range 4–12 N, T2 tension, sample #2 (10.5281/zenodo.17822016)
• Part 8: Extended bow force range 4–12 N, T2 tension, sample #2 (10.5281/zenodo.17822037)

In part 3, "cold" refers to a freshly mounted, brand-new string, while "warm" refers to the same string after being played during the cold measurement session.

Main reference: Lampis, A., Chatziioannou, V., & Scavone, G. (2025). Experimental analysis of cello string types: influence on playability and tonal characteristics using Schelleng diagrams. Proceedings of Meetings on Acoustics, 58(1), 035013.

Related references: Lampis, A., Mayer, A., & Chatziioannou, V. (2024). An experimental approach for comparing the influence of cello string type on bowed attack response. JASA Express Letters, 4(11).

Lampis, A., Mayer, A., & Chatziioannou, V. (2024). Assessing playability limits of bowed-string transients using experimental measurements. Acta Acustica, 8, 44.