An experimental investigation of two active segmented partition arrays

This paper addresses the construction, measurement, and analysis of two active segmented partition arrays ASP arrays for use in active sound transmission control. The control objective for each array was to actively minimize principal transmitting surface vibrations to induce high transmission loss. The arrays incorporated four adjacent lightweight modules with composite single or double leaves and small loudspeakers as actuators. A normal-incidence transmission loss measurement system was developed to evaluate their performances under passive and active conditions. Measurement results were compared to results for passive benchmark partitions and theoretical predictions. Four decentralized single-error-input, single-output filtered-x controllers were used with the arrays. They were shown to perform at least as well as a centralized multiple-error-input, multiple-output controller, with good error signal reductions and stability. Scanning laser vibrometer measurements confirmed the ability of the double-composite-leaf ASP to efficiently and globally minimize its transmitting surface vibrations to produce high transmission loss. Its average transmission loss over the active measurement bandwidth 30–290 Hz was 56 dB—a full 34 dB greater than that of the single-composite-leaf ASP. The work confirms that a properly configured lightweight ASP can produce very high transmission loss through vibration control techniques. © 2005 Acoustical Society of America. DOI: 10.1121/1.2047348