plan and axon diagrams
with Howard Huang and Ajay Manthripragada
Periphon is a pair of concrete sound reflectors, similar to sound collection devices built along the British coast during World War II as an early form of radar. The installation reconnects two areas of the Mendel Music Library [built by Juan Navarro Baldeweg from 1994-97] that were isolated acoustically—but not optically—by a glass partition. The result is the aural equivalent of a periscope, allowing conversation across the partition to take place through the act of voice-throwing, producing an uncanny orthogonality between sound production and sound reception.
The installation is made up of two concrete paraboloidic shells. Each shell is a fragment of a different paraboloid, sharing a common focus and axis but differing in focal length in order to account for the skewed geometry of the library's floor plan. Despite their very different lengths and curvatures, the shells are acoustically symmetrical: an incoming sound wave [parallel to the shared axis] that hits the outermost point on the long shell is reflected through the focus to the innermost point of the short shell, at which point it is reflected out parallel to the axis once again.
The shells were fabricated over the course of two weeks. The CNC mill was used to produce the MDF formwork, which was then shellacked for maximum smoothness. A plywood substrate, made to mimic 3/4" contours of the front surface, became the rear wall of the formwork and the eventual mounting surface for the legs. The gap was filled with anchoring cement. After curing, the tenacious formwork was removed by repeatedly dropping the entire assembly from a height of six inches. The shells were then mounted in situ on legs made of 3/4" steel tube stock, centered vertically at ear-height.
Periphon was part of the exhibition sounded() at the Princeton University Mendel Music Library. It was published in Pidgin 6.