Design of Acoustic Chamber for Loudspeaker Measurements

The design of a small anechoic chamber dedicated for measurements of the acoustical parameters of hi - fi loudspeaker systems is presented in the paper. Sound insulation, noise from technical equipment and acoustics of the room are discussed. The laboratory consists of three main rooms: anechoic chamber, control room and equipment room. The chamber of 140 m
³
effective inner space with full anechoic condition from 100 Hz is planned as “box in box” construction. The acoustics of the measurement room allows for loudspeaker measurements according to EN 60268-5 standard. Sound absorption of acoustical wedges made from polyurethane foam and rockwool is also measured and compared. The disadvantages of foam wedges are discussed. The new idea of loudspeaker-microphone-walls setup that allows for measurement in the frequency range above 80 Hz is proposed. This frequency lies below the chamber cut-off frequency. The applied technical solutions of sound insulation are also discussed.