1. Blue Tooth Speaker
2. Portable Speaker
The accordion (black one in between) enhances the sound - a good idea. So the sound is not very poor.
The input is a phone plug. The tiny Li-Ion Battery is connected to a USB connector to charge it but no charger IC found. It has an LED indicator for 'On'. It works anyway. The Audio Amp IC is CG4812. I cannot find the spec on the internet. I found the spec of similar number SGM4812 (package MSOP10).
3. Very simple Portable Speaker (inside)
This one is terrible not just its sound. The input is only one phone plug. Though I found a very tiny Li-Ion Battery no USB connector to charge it. So this is a disposal type of power from the charged battery. The battery is seriously damaged. It worked anyway. The Audio Amp IC is 8003.
sptt