Exploring effects on sound attenuation in a snare drum using custom designed 3D-printed damper system

• Main Author: Leow, Yixuan
• Other Authors: Leong Kah Fai
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Mechanical engineering::Prototyping; Engineering::Mechanical engineering::Mechanics and dynamics; Science::Physics::Acoustics; Visual arts and music::Performing arts
• Online Access: https://hdl.handle.net/10356/141862
• Institution: Nanyang Technological University

In a world of moving parts (and stationary ones subject to unwanted movement), the astute engineer possesses a fundamental grasp of structural dynamics, and in particular, vibration. This grasp could very well extend to the field of acoustics and involve superb, but underserved resonators such as the musical drum. This study aimed to evaluate the effects a custom-designed 3D printed damper system applied to the underhead a snare drum. The study was conceived in response to gaps in existing commercial systems meant to achieve muted drum practice with authentic feedback. While accessories catered to this need exist, none have leveraged on the modal behaviour of the drum and well-established structural damping technologies, like the tuned mass damper, to effectively preserve of the sound quality of the drum. The objectives of the damper system, therefore, were attenuation of loudness, as well as retention of the timbre of the snare drum. The rebound behaviour of the drum was also measured. Dampers in the form of end-loaded cantilevers were tuned to the (0,1), (1,1) and (2,1) modes of a snare drum. Damper head shape was varied, and felt and polyurethane layers at the contact interface were also included. A total of 48 configurations were tested on the snare drum with its snare head removed. Each test obtained a sound pressure level (SPL) and audio recording of a drumstick hitting the batter head equipped with the damper configuration. SPL measurements were extracted as LCpeak values and LCImax values, the latter distributed across 1/3 octave bands. From the audio recordings, the average spectral centroid during the drumstick hit and the frequencies of the three modes was obtained. Results showed that the frequency tuned dampers could target specific frequencies in the drum but did not attenuate loudness to a perceptible extent. Possible factors included a lack of energy dissipation mechanisms, and an oversaturation of sound intensity. The spectral centroids, first and third modes were observed to increase significantly, indicating a brightening of the drum sound. Certain configurations, however, preserved the first mode completely. As a whole, the second mode was also less compliant to effects from the damper system due to the positioning of the dampers. This study shows that the damper system developed did not perform up to commercial standards, but has potential for greater attenuation of loudness and preservation of the spectral centroid and first three modes of the drum. It recommends that further studies be taken to improve the attenuation mechanism involved with a more sophisticated model for effective damper design.