Portal 2 Companion Cube Audio Speaker : 23 Steps (with Pictures

3D Printed Portal Weighted Companion Cube

Portal 2 Companion Cube Audio Speaker : 23 Steps (with Pictures) - Instructables

Portal 2 Weighted Companion Cube Subwoofer

Portal 2 - Playstation 3 : Video Games

.com: [Upgraded] SOCOVEZ Portable Bluetooth Speaker with Double Subwoofer,Bluetooth Speaker with Audio Recording/LED Light/TWS, Portable Speaker Support MIC/AUX/USB/Micro SD Input，Perfact for Party : Electronics

Portal 2 Companion Cube Audio Speaker : 23 Steps (with Pictures) - Instructables

Weighted storage cube end table : r/gaming

Let's Make Companion Cube Speakers!

Steam Community :: Guide :: PeTI plus

Portal 2 Companion Cube Audio Speaker : 23 Steps (with Pictures) - Instructables

Valve's Secret Weapon

Arduino Mega, Hackaday