[IEEE 2019 Fifth Indian Control Conference (ICC) - New Delhi, India (2019.1.9-2019.1.11)] 2019 Fifth Indian Control Conference (ICC) - Exploring Operational Frequency Ranges for Actively-Tuned Single-Mass, Multiple-Frequency Vibration Absorber**This work was supported in part by the Czech Science Foundation under Contract 17-20943S to the CVUT and the US National Science Foundation grant CMMI-1462301 to University of Connecticut. The second author was on a sabbatical visit at CVUT in Prague.