Optimization of the Bass Management Filter Parameters for Multichannel Audio Applications

Traditionally, room acoustic equalization is performed to improve sound quality in an environment. In a multi-channel audio system employing room equalization, the selection of the bass management filter parameters, such as the crossover frequency and the decay rate for the subwoofer and satellite, is important for accurate reproduction of playback sound. Presently, many systems (e.g., home-theater receivers) have selectable crossover frequencies with fixed decay rates. A poor choice of the crossover frequency and decay rates can result in undesirable interactions, in the subwoofer-satellite net response, even after equalization. Such interactions, due to complex addition (i.e., phase and amplitude) of the subwoofer and satellite response, manifests as a broad notch in the net magnitude response which in turn leads to a loss of sound output in the crossover frequency region. In this paper, we present an automatic method for selecting the bass management filter parameters, based on an objective measure, for multi-channel audio applications. The proposed method allows better control of the resulting subwoofer-satellite response, around the crossover region, thereby significantly improving audio quality