The speakers have integrated force sensor resistors, as the user starts to stack the weighted forms the speaker turns on, and as you stack each additional piece the volume also increases. The weights have been casted in identical mass to insure a consistent volume increase. The cohesive form of the pieces are visual representations of audible sound getting louder when they are stacked, and the opposite when pieces are removed.
The speakers have been delicately created with a laser cut piece of white ash wood that allows for great quality sound.
"Stack encourages a real interaction and a hugely visual and tactile system of control. Playfulness and an emotion of surprise is achieved which sets Stack apart from the other options."