Modification of low frequency response of loudspeaker - uses elastically compressible stopper to selectively block tuned orifice

摘要

A loudspeaker system with an adjustable low frequency response is formed by combining an air suspension system with a tuned orifice system. The frequency response is modified by mechanically selectively blocking the tuned orifice. An enclosure for a loudspeaker unit comprises a number of sealed compartments with openings in the front panel (27) in which loudspeaker are mounted enabling the system to operate as an air suspension system. A tuned orifice (57) enters one loudspeaker compartment providing communication between interior and exterior. An elastically compressible stopper (15) has a support axis (61, 63, 65, 67) to make it rigid for insertion into the orifice.