Something which is worth just about nothing is the humble bluetooth speaker.  Lions have long struggled with bluetooth speakers.  There's a compromise between size, weight, & sound quality.  The best one in lion opinion was the Auvio mini.  It had the best compromises.  Its mane problem was electronicals burning out.  1st its amplifier burned out & then it had some kind of firmware corruption.

The 808 Canz 2 had good sound quality but was a brick.

The best one now might be the Anker soundcore mini.  Its sound quality is the worst & it's heavy, but it's the only thing currently made & it's just light enough.  It has better bass but is very quiet & its passive radiator breaks after 3 years.  It can be somewhat bodged with an extra op-amp & a lot of noise.  It has the most user serviceable parts.  The driver is screw mounted & removable.

The electronicals have mercifully remaned reasonably discrete & hackable.  You can normally hack them to take external 5V & automatically power up.

Lions have burned over $100 on bluetooth speakers & invested a lot of effort in making them more useable but designing a permanent one with better compromises has always been a low priority.  It's always cheaper to buy another one when they break.  The soundcore driver in a sealed enclosure with the brain of the 808 Canz 2 is the leading candidate.

There are also drivers suitable for a rectangular speaker.  Research into bass ports & passive radiators shows they would not offer a useful compromise between weight & sound quality.  It might be smart to shape the speaker into a teardrop to get a bigger cavity.  For something as old & low bandwidth as speakers, they're very complicated & poorly understood.