Vibration Analysis of Setar for Extracting the Frequency Response Function (FRF)
Hossein Mansour, Siamak Arzanpour, Hedayat Alghassi, Mehdi Behzad · 2009
Extraction of the frequency response of a musical instrument is the first step to analyze its vibration characteristic. This research introduces the results of several experiments implemented on Setar, a Persian long-necked lute. Setar has a wooden, reflective sound-box which is highly coupled with its surrounding air. High level of damping in addition to the composite properties in Setar, consequences dissimilar frequency domain vibration patterns. At lower frequencies, the response exhibits very distinct modal behavior, while in higher frequencies an overall effect of close modes is demonstrated. In this paper different approaches are utilized to handle both frequency regimes; and their advantages and limitations are compared to each other. The utilized methods are swept sine excitation, impact hammer, and the traditional Tap-Tone method. The characteristics of force excitation on body are first investigated, and then the frequency response function of Setar’s body is extracted between the excitation force as the input and resultant sound and acceleration as the outputs. This study not only leads us to modifications in design of Setar, but also serves as a platform for numerical modeling.