Abstract: A portable charging case is provided. The case includes a charging interface configured to establish a power transfer connection with a wireless audio device having a battery. The case includes charging circuitry configured to determine a voltage of the battery. The charging circuitry is further configured to, if the voltage is less than or equal to an undervoltage lockout, charge the battery in pre-charging mode. In pre-charging mode, the charging circuitry is configured to apply a constant pre-charging voltage to the battery. The charging circuitry is further configured to switch from pre-charging mode to standard charging mode when the voltage exceeds the undervoltage lockout value. The charging circuit is further configured to determine the voltage by (1) powering on, via a case power source, the wireless audio device; (2) applying, pre-charge load to the device battery; (3) retrieving the voltage; and (4) transmitting the voltage to the case.

Abstract: A portable charging case is provided. The case includes a charging interface configured to establish a power transfer connection with a wireless audio device having a battery. The case includes charging circuitry configured to determine a voltage of the battery. The charging circuitry is further configured to, if the voltage is less than or equal to an undervoltage lockout, charge the battery in pre-charging mode. In pre-charging mode, the charging circuitry is configured to apply a constant pre-charging voltage to the battery. The charging circuitry is further configured to switch from pre-charging mode to standard charging mode when the voltage exceeds the undervoltage lockout value. The charging circuit is further configured to determine the voltage by (1) powering on, via a case power source, the wireless audio device; (2) applying, pre-charge load to the device battery; (3) retrieving the voltage; and (4) transmitting the voltage to the case.

Abstract: In one aspect, a speaker kit includes a first portion of a speaker housing, and an electroacoustic driver that can be secured to the housing first portion. The kit has one or more additional portions of the speaker housing. One of the one or more additional housing portions has at least one electrical component secured thereto. The kit also has one or more mechanisms that can be used to hold the housing portions together such that the housing portions form an acoustic seal that encompasses an acoustic volume. The one or more mechanisms are removable from the housing portions such that the housing portions can be moved away from each other without damage to the housing portions or the one or more mechanisms.

Abstract: In one aspect, a speaker kit includes a first portion of a speaker housing, and an electroacoustic driver that can be secured to the housing first portion. The kit has one or more additional portions of the speaker housing. One of the one or more additional housing portions has at least one electrical component secured thereto. The kit also has one or more mechanisms that can be used to hold the housing portions together such that the housing portions form an acoustic seal that encompasses an acoustic volume. The one or more mechanisms are removable from the housing portions such that the housing portions can be moved away from each other without damage to the housing portions or the one or more mechanisms.

Abstract: A person monitoring system, such as a baby monitor a monitored unit including a microphone for transducing radiated sound waves and sound waves emanating from the person to a received audio signal and circuitry for removing from the received audio signal a portion of the received audio signal corresponding to the radiated sound waves to provide an audio signal corresponding to the sound waves emanating from the person.