DEVICES AND METHODS TO IMPROVE FREQUENCY OUTPUT OF PORTABLE AUDIO DEVICE Russian patent published in 2012 - IPC H04R1/02 H04M1/11 

FIELD: information technologies.

SUBSTANCE: passive acoustic structures are disclosed, as well as portable audio devices arranged as capable of being used with passive acoustic structures, and methods to improve frequency output of a portable device loudspeaker arranged as capable of being used with the disclosed passive acoustic structure. The disclosed portable audio device may include a hole closer to a device loudspeaker resonator, a curtain or a door, to open and close the hole so that the device interacts with a joint station of the passive acoustic structure, comprising a labyrinth or a system of a transmission line, which may increase a frequency range of the system. For an end-user to enjoy musical and multimedia features of a portable audio device and in particular a mobile communication device, the above passive acoustic structure may represent increased lower frequencies for a typically small loudspeaker of a portable audio device without an additional loudspeaker and accordingly additional circuits.

EFFECT: improved frequency output of a loudspeaker.

12 cl, 12 dwg