The Acoustic Mirror is a low-tech concrete speaker sold in only 100 hand-made and numbered copies. It is about 33 centimeters long by 33 centimeters high and between 11 and 6 centimeters wide. In order to amplify the sound, geometry has been working as a double ellipse focus with a resonance box at the base. The EPFL acoustic laboratory calculate an increase in sound flow of 9 decibels only due to materials and its precise geometry. It works with smartphones as well as portable speakers. The design, inspired by the early 20th century English acoustic radars, was initiated by Mikael Sachs and Simon Zangger at ECAL. Then it was produced and presented at Cartha open launch magazine and Design days event in Geneva at pavillon Sicli by Christophe Alhanko, Benjamin Baertschi, Loris Guillard, Mikael Sachs and Simon Zangger.