# US 2014/0193005 A1 · Audio Speaker System with Semi-Shared Passive Radiators > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193005 A1 - Document ID: US20140193005A1 - Status: Published application - Kind: A1 - Application number: 13/735,829 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Inventors: Jason R. RIGGS - Web page: https://patentgrep.com/patent/US20140193005A1 ## CPC - H04R 5/02: Spatial or constructional arrangements of loudspeakers - H04R 1/2834: {for loudspeaker transducers} - H04R 1/2873: {for loudspeaker transducers} - H04R 2205/022: Plurality of transducers corresponding to a plurality of sound channels in each earpiece of headphones or in a single enclosure - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract A multi-channel stereo speaker system includes acoustically separated but mechanically connected chambers containing active drivers to reproduce sound for each channel, and a passive radiator for each chamber to help tune the frequency response of the chamber. Passive radiators are positioned and oriented so that their movements tend to cancel each other out. ## Claims ### Claim 1 A multi-channel loudspeaker comprising: an enclosure subdivided into a plurality of separate chambers; a plurality of active drivers, one active driver in each of the separate chambers; and a plurality of passive radiators, one passive radiator in each of the separate chambers, wherein the passive radiators are oriented so that physical movement of a first passive radiator in a first separate chamber is at least partially counterbalanced by physical movement of at least a second passive radiator in a second, different separate chamber. ### Claim 2 (depends on 1) The multi-channel loudspeaker of claim 1, further comprising: an audio signal processing network to mix low-frequency portions from each of a plurality of channels so that audio signals to be reproduced by the plurality of active drivers have similar low-frequency portions. ### Claim 3 (depends on 2) The multi-channel loudspeaker of claim 2 wherein the audio signal processing network is a passive network. ### Claim 4 (depends on 2) The multi-channel loudspeaker of claim 2 wherein the audio signal processing network is an active network. ### Claim 5 (depends on 1) The multi-channel loudspeaker of claim 1 wherein a first passive radiator faces a top of the enclosure, and a second passive radiator faces a bottom of the enclosure. ### Claim 6 (depends on 1) The multi-channel loudspeaker of claim 1 wherein a first passive radiator faces a left outside of the enclosure, and a second passive radiator faces a right outside of the enclosure. ### Claim 7 (depends on 1) The multi-channel loudspeaker of claim 1 wherein a first passive radiator faces a front of the enclosure, and a second passive radiator faces a rear of the enclosure. ### Claim 8 (depends on 1) The multi-channel loudspeaker of claim 1 wherein a first chamber is separated from a second chamber by a vented chamber, and wherein a first passive radiator faces a second passive radiator, both of said passive radiators facing into the vented chamber. ### Claim 9 (depends on 1) The multi-channel loudspeaker of claim 1 wherein the plurality of separate chambers is two separate chambers. ### Claim 10 (depends on 1) The multi-channel loudspeaker of claim 1 wherein the plurality of separate chambers is five separate chambers. ### Claim 11 A multi-channel loudspeaker comprising: an enclosure subdivided into a plurality of separate chambers; a plurality of active drivers, one active driver in each of the separate chambers; and means for passively tuning a resonant frequency of each of the separate chambers, wherein action of the means for passively tuning the resonant frequency of a first separate chamber opposes action of the means for passively tuning the resonant frequency of a second separate chamber. ### Claim 12 (depends on 11) The multi-channel loudspeaker of claim 11, further comprising: a signal mixing network to mix audio signals for a plurality of channels so that low-frequency portions of the signals for each channel become more similar. ### Claim 13 (depends on 11) The multi-channel loudspeaker of claim 11, further comprising: a signal processor to reduce low-frequency channel separation between audio signals for a plurality of channels. ### Claim 14 A two-channel (stereo) loudspeaker comprising: a left-channel chamber with at least one left-channel active driver and at least one left-channel passive radiator; a right-channel chamber with at least one right-channel active driver and at least one right-channel passive radiator, wherein the left-channel chamber and the right-channel chamber are mechanically connected but acoustically separated; and directed centerlines of at least one left-channel passive radiator and at least one right-channel passive radiator are substantially coincident but oriented in opposite directions. ### Claim 15 (depends on 14) The two-channel (stereo) loudspeaker of claim 14 wherein the directed centerline of each passive radiator is parallel to a directed centerline of an active driver of the same channel. ### Claim 16 (depends on 14) The two-channel (stereo) loudspeaker of claim 14 wherein the directed centerline of each passive radiator is perpendicular to a directed centerline of an active driver of the same channel. ### Claim 17 (depends on 14) The two-channel (stereo) loudspeaker of claim 14 wherein the left and right chambers are separated by a sealed partition wall. ### Claim 18 (depends on 14) The two-channel (stereo) loudspeaker of claim 14 wherein the left and right chambers are formed within a single substantially airtight enclosure. ### Claim 19 (depends on 14) The two-channel (stereo) loudspeaker of claim 14 wherein the left and right chambers are separated by a vented chamber. ### Claim 20 (depends on 14) The two-channel (stereo) loudspeaker of claim 14 wherein the left and right chambers are mechanically connected by an outer enclosure of the loudspeaker.