Detection of subwoofer depending on crossover frequency and spatial angle between subwoofer and main speaker

摘要

Since the direction of sound is not perceived at very low frequencies, it is feasible to use only one subwoofer for low frequency reproduction in multi-channel audio setups. A listening test was conducted to find the crossover frequency where the listeners begin to detect the subwoofer presence. The test was arranged in a symmetrical listening room using four pairs of speakers, arranged symmetrically in four angles to the front of the listener to equalize the timbres as well as possible in reverberant conditions. The detection judgment was done using a version of the two alternatives forced choice (TAFC) adaptive method, with which the 75% point of the psychometric function was found. With the used sound samples the crossover frequency could be set to about 120 Hz before the subwoofer became detectable. No correlation was found between the highest acceptable crossover frequency and listening angle when the angle exceeded 30°.