These are some subwoofer modules I have. Most of these are used in TVs however I've seen the Tang Band in bluetooth speakers.
Timestamps:
5:18 Philips 242226440196
6:35 Samsung BN9606044A
7:40 Sony 100985411
8:49 Tang Band T32190S
10:00 Bass tests & teardown
Songs:
Soul Persona Underwater Love
My Stoner Mind Bassrider