Free-field measurements for a loudspeaker system in a normal room--Using digital signal processing techniques

In this paper, free-field measurements (frequency responses and directional characteristics) in a normal room are described. Two methods for reducing reflected waves are investigated. The Comb Lifter method, filtering in cepstrum domain, and the Moving Average method, with variable averaging points, are described. Approximate free-field responses in full audio frequency band are obtained with reduced reflections from the floor, walls and ceiling.