Loudspeakers tuned as optimal acoustic absorbers can significantly reduce damaging, low frequency, reverberant noise in a full-scale launch vehicle fairing. Irregular geometry, changing payloads, and the compliant nature of the fairing hinder effective implementation of a passively tuned loudspeaker. A method of tuning the loudspeaker dynamics in real time is required to meet the application re...

This paper addresses the problem of loudspeaker test. Two applications are investigated: loudspeaker manufacturing fault detection and maintenance. In order to comply with practical requirements, we propose a new, brief, nonstationary test signal. Recorded loudspeaker responses are processed using an improved time-frequency decision algorithm. The fault detection procedure is tested with real d...

This paper presents a novel flat loudspeaker with improved sound frequency response. Flat loudspeakers provide advantages of compact dimensions and high durability. Known flat loudspeaker technology is based on high modal density. However, the resonances in the panel are complex and difficult to control, which often leads to complicated computations and insufficient low frequency response. The ...

The present study extends our previous work [Furihata et al., J. Acoust. Soc. Am. 114, 174-184 (2003)] by investigating our electrodynamic planar loudspeaker when driven by a 12 bit digital signal with noise shaping. Changing the structure of the loudspeaker can lead to improvement, but in this paper improvements that can be made using signal processing are investigated. Results show that the d...

Dependence of the performance of feedforward active duct noise control on secondary loudspeaker parameters is investigated. Noise reduction performance can be improved if the force factor of the secondary loudspeaker is higher. For example, broadband noise reduction improvement up to 1.6 dB is predicted by increasing the force factor by 50%. In addition, a secondary loudspeaker with a larger fo...

Mirror filter is used for the compensation of nonlinear distortions for electro-dynamic loudspeaker systems and is based on the nonlinear differential equations. The design of Mirror filter requires the estimated parameters of a target loudspeaker system. If you obtain the corresponding parameters of a target loudspeaker system and arrange Mirror filter designed using those parameters in front ...