The code allows you to use your TV's IR remote control Vol Up, Vol Down, and Mute buttons to control speakers that come with their own IR remote. It's a pain to keep 2 remotes at hand.
I used hot glue to mount the Nano between the grill and speaker.
The blue led and IR Rcvr face the user, while the IR Led faces backward towards the speakers' IR remote sensor.
Space was tight, and you can see from picture I used creative soldering to place the components. I used a USB cable plugged into a USB port on the TV to power the board, and with one end removed, I soldered the Black (GND) and Red (+5VDC) USB wires directly to the 5V & GND inputs of the Nano.