A class D amplifier injects a detection frequency component into audio output terminals to identify connected external loudspeakers.
System detects relative user position to dock ports and automatically routes correct stereo channels, eliminating manual identification errors.
Fluid coupling expands the back cavity volume to generate sufficient low-frequency sound for out-loud listening.
Near-field magnetic induction relays Bluetooth signals through water, maintaining continuous media playback when swimmers submerge.
Telescopic cylinders form a variable-volume woofer enclosure that resolves the contradiction between portability and low-frequency sound quality.