DY-SV5W

Polyphonic

install via pipx

basically adafruit solution

The whole problem was the following.....
It was a ground problem
It is weird
But the problem was, for one, we need to GND both GND pins
Lastly, the GND of the data wire to the amp must be as close as to the GND pin of the DFPlayer
So, we cannot just plug the GND data wire into GND. It has to be like next to the pin of GND on the DFPlayer
I pulled the GND out of the GND that is between the SPK 1 and SPK 2 and instead just left the GND of the data wire there. I think that is how it is suppose to be
The GND on the other side is to be plugged into the negative terminal
What remains is a hum, not a bep bep bep bep, but the hum is much more tolerable.

NewPipe; open source; download through F-Droid client to manage updates.

modified omxplayer sync
https://github.com/PaulSlocum/omxplayer-sync-3

https://github.com/heisters/node-omxplayer-sync-devops

https://github.com/bmoren/node-omxplayer-sync

https://github.com/ktrofimov/omxplayer-udpsync

uses custom built omxplayer:
https://github.com/turingmachine/omxplayer-sync
https://medium.com/@ethanbresnick/multi-screen-video-synchronization-23aae0dc2e6f
https://www.khm.de/~sievers/net/omxplayer-sync.html