A theoretical study of spatial sound equalisation in an extended region in a room has been carried out. The purpose is to reproduce sound without significant spatial fluctuations and to minimise the spectral colouration at low frequencies in a specified region of the room. The problem is first studied by means of an idealised frequency domain model. The analysis is based on the calculation of the complex source strengths that minimise the difference between the actual sound pressure and the desired sound pressure in the listening area. Results in relation to the position of the sources, the frequency range, and the size and location of the listening area are presented. However, the frequency-domain approach results in non-causal impulse responses that can be realised only at the expense of a delay. Therefore, this analysis is supplemented with a study of the equalisation carried out in the time domain. Here, a solution constrained to causality is determined. The duration of the impulse response should be minimised as well in order to avoid echos, which are undesirable in the reproduction of transient signals. This causality-constrained equalisation is compared with the optimal solution obtained in the frequency domain.
|Title of host publication||Proceedings of the Fifth International Congress on Sound and Vibration|
|Place of Publication||Auburn, AL|
|Publisher||The International Institute of Acoustics and Vibration|
|Publication status||Published - 1997|
|Event||5th International Congress on Sound and Vibration - Adelaide, Australia|
Duration: 15 Dec 1997 → 18 Dec 1997
Conference number: 5
|Conference||5th International Congress on Sound and Vibration|
|Period||15/12/1997 → 18/12/1997|
Orozco-Santillán, A. (1997). Active equalisation of the sound field in an extended region of a room. In Proceedings of the Fifth International Congress on Sound and Vibration (pp. 287-294). The International Institute of Acoustics and Vibration.