Here is a list of every you need:
1 or 2 old speakers (passive)
1 bluetooth audio receiver and amplifier:
1 dc male cable:
and 2 battery packs (4 batteries in a pack or more) with batteries (duh!)
Step 1: Connect!
Now connect the + and - from the battery pack, and the other ends to the DC cable, use speaker cables to connect the speakers to de amplifier, and plug in the DC cable, now you can pair you bluetooth device!!!
inspired by a video of diy perks: