Abstract: An automatic return system includes a charging station and an automatic traveling device. A sound wave transmitter is disposed on the charging station, and the automatic traveling device includes a sound wave receiver, a processor, and a controller. Controlling, by the controller when an automatic traveling device starts to return, a sound wave receiver to continuously detect sound waves in different directions transmitted by a sound wave transmitter; performing, by the processor, intensity analysis on the sound waves in different directions continuously detected by the sound wave receiver, and obtaining the direction of a sound wave with the highest sound intensity; and controlling, by the controller, a traveling direction of the automatic traveling device according to the direction of the sound wave with the highest sound intensity, so that the automatic traveling device returns to the charging station.

Abstract: The inventive subject matter provides a reflex tube or port that includes a circuit board and a speaker enclosure that incorporates such a reflex tube. The circuit board is mounted about the reflex tube and can be configured so as to form a resonance chamber with an interior wall of a speaker enclosure to form a resonance chamber. Such a reflex tube can also include one or more connections.

Abstract: The inventive subject matter provides a reflex tube or port that includes a circuit board and a speaker enclosure that incorporates such a reflex tube. The circuit board is mounted about the reflex tube and can be configured so as to form a resonance chamber with an interior wall of a speaker enclosure to form a resonance chamber.

Abstract: The inventive subject matter provides a reflex tube for a speaker enclosure and a speaker enclosure that includes a reflex tube, where the reflex tube includes one or more cables and/or connections disposed within it. The connection may be affixed to a connection support, which is in turn affixed within the reflex tube. The connection support may be utilized to reduce air turbulence within the reflex tube.

Abstract: The present invention refers to a device for correcting the acoustic properties of an environment, comprising also acoustic emission means (4, 8, 8c, 8d, 8e, 8f, 8h, 8g), apt to be connected to a sound source to cover said environment; and means (3, 5, 7) for lighting said environment.