If you have a spare pair of small speakers and you want to make them wireless (bluetooth), check this guide.
The method is very simple and you only need 2 items, a bluetooth receiver/amplifier and an old USB cable. You can buy the bluetooth receiver I used for this guide here.
Open up your speakers/headphones and remove everything from inside, you won't need them. This board has everything you need to power up your speakers.
The board requires 5VDC, so cut your USB cable and solder the V+ and V- wires on the board. Check the polarity with a multimeter. Now solder a pair of wires for each speaker. Beware for the speakers polarity.
You are done. Connect the USB cable to your PC/Laptop/Power Bank and wait until you hear a chinese voice from the speakers. I don't know what is saying, but I believe its says that it has not connected to any source yet.
Now from your PC or smartphone, enable the bluetooth and search for "Hazy Audio" and connect to it. You will hear from your speakers something in Chinese, meaning that your speakers are now connected to the source.
You can use the volume bar of your source to increase or decrease the volume. Enjoy your new bluetooth speakers.