I made this multimedia speaker in my spare time, and it works well..
going in the topic
There are just idle Bluetooth headsets, two-channel power amplifier board, level indicator IC, idle MP4, speakers, etc., so I suddenly made this multimedia speaker.
The two-channel power amplifier board and MP4 power supply use a 2 * 2200 mAh polymer battery (so MP4 can display power supply), and the Bluetooth and level indicators are powered by a 1200 mAh polymer battery. Continuous use time is actually measured at full power for up to 20-25 days without charging
The playback distance of Bluetooth can be up to 10 meters. Here, a large antenna is added to the Bluetooth module, that is, the FET is scrapped.
1: Welding of Bluetooth module
2: Power amplifier board and MP4
3: Welding of mp4 MINI USB holder
4: After welding the components
5: The production of the outer panel is made of plywood, hand-punched and polished.
6: Level indicating test machine and welding
7: LED installation
8: Assemble, debug, install the sound-absorbing cotton horn. The diaphragm is installed in the middle to help increase the bass effect.
Sound-absorbing cotton helps to show the bass