The Cache:
Our group has being chasing a community of Treasure Hunters for generations across the globe.
We manage to intercept a letter containing information about a small coded Vault where short messages can be passed about the hidden treasures and coin size samples. The treasures can be placed to show other hunters where and what can be found. This small objects travel worldwide containing hidden information about their origin and the places they have been and who had them. This would be a major advantage for our group to catch this treasure hunters.
The Letter contained the coordinates and the message... The Vault Code is the year of its Invention (4digits)... What can this mean?
Rushing to the coordinates to secure the Vault, we couldn't find it, so the only possible assumption was that they moved it and the letters stopped.
We were in a dead end until a few days ago the encrypted audio file was intercepted: https://youtu.be/a547O9L2MQg
We thrust, since the Vault was never found, the code will be the same and the message is the transmission of the new coordinates for the Vault.
Coordinates Checker - 
Pin Code Checker -
You can validate your puzzle solution with certitude.
