通常室内におけるスピーカ自由音場特性の測定

概要

論文の詳細を見る
Free-field measurements for a loudspeaker system in a normal room (frequency responses, directional characteristics, phase characteristics and group delay characteristics) are studies. Two methods for reducing reflected waves are investigated. 1) Comb Lifter method : filtering in quefrency domain using three CLs with gentle slope. 2) Moving Average method : smoothing in frequency domain using MA with variable averaging points. The LC method has an advantage of relative design ease, that is, CL constants are related to dimensions of a room. The MA method is able to vary easily its averaging points, or frequency window lengths F_w_'_s. That is, a shorter F_w is used for the lower frequency region and a longer F_w is used for the higher frequency region to reduce reflected waves effectively. The MA method is applicable to rapid processing. Approximate free-field characteristics in full audio frequency band are obtained with reduced reflection from the floor, walls and ceiling. These measuring methods can be carried out in any normal room without the use of an anechoic chamber. They are useful for the development of loudspeaker systems.
社団法人日本音響学会の論文
1980-06-01