ALEXANDRIA, Va., Oct. 28 -- United States Patent no. 12,452,586, issued on Oct. 21, was assigned to ALPS ALPINE Co. LTD. (Tokyo).
"Acoustic device" was invented by Ryo Ito (Fukushima, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A speaker unit on the left side and a speaker unit on the right side are included in a case positioned behind a listener. Sound generation openings and bass-reflex ports are formed in the case on the left side and right side. From each sound generation opening, sound pressure generated forward by the relevant speaker unit is output. Each bass-reflex port communicates with an air chamber to which sound pressure behind the speaker unit is transmitted. With each sound generation...