PURPOSE: To eliminate sound wave reflecting body and reproduce uniform sound fields by arranging speakers with functions for medium and high range and low range on the whole of at least a wall face and radiating reproduced sound waves in a plane.

CONSTITUTION: Wall faces 10 and 13 and wall faces 11 and 12 parallelly opposed to each other respectively are formed, and speakers 1 for medium and high ranges and speakers for a low range are installed on the whole face of the wall 10. The radiation of the sound waves reproduced by the speakers 1 and 2 in a plane eliminates sound wave reflecting bodies on the wall. With this constitution, uniform sound fields can be reproduced, and even in the case of a rectangular listening room which is easy in the execution of construction, acoustic hindrance caused by flash echo can be prevented.