Note: This content is accessible to all versions of every browser. However, this browser does not seem to support current Web standards, preventing the display of our site's design details.


Uncontrollable Modes in Double Wall Panels


O. Kaiser, A. Julius, Stan Pietrzko, M. Morari

Rome, Italy, International Congress on Acoustics, no. 17, Paper no. 7P.09

Double-glazed windows have a poor transmission loss at low frequency. Since the passive means are more or less exhausted one could think of using an active controller to increase the transmission loss. In the work presented here two speakers in the cavity between the panes are used as actuators. A modal model is derived and validated with data from a laser scanner and measured transfer functions on the structure. From an analysis of this model it is shown that for certain configurations of the double wall panel some modes of the coupled system are uncontrollable and unobservable by speakers and microphones in the cavity, thus limiting the achievable controller performance. This theoretical result is verified by feedforward control experiments on two types of double-glazed windows. For the fully controllable window the transmission loss achieved by the active controller is about twice as large as for the window with uncontrollable modes.

Further Information

Type of Publication:


File Download:

Request a copy of this publication.
(Uses JavaScript)
% Autogenerated BibTeX entry
@Article { KaiEtal:2001:IFA_215,
    author={O. Kaiser and A. Julius and Stan Pietrzko and M. Morari},
    title={{Uncontrollable Modes in Double Wall Panels}},
    journal={International Congress on Acoustics},
Permanent link