Since the National Constitution Center’s genesis, it has become one of the most sought after spaces in the Philadelphia region for special events that include – political speeches, corporate functions, weddings, private parties and many other types of activities. This is primarily because of the stunning architectural look and feel to the upper level of the Hall as well as the caché of holding one’s event at such an important institution.
The museum’s Grand Hall is an enormous atrium used by visitors to NCC as a gathering space prior to entering other areas of the museum. However, as with so many museums, the hall’s acoustics were not appropriately “tamed” in the beginning to allow for a pleasing aural experience during events. Combining a room volume of over one million cubic feet with surface materials that include stone flooring, full-height glazing to the exterior and undulating drywall ceilings resulted in excessively loud music events and speeches that were barely intelligible.
NCC event staff reached out to Steve Haas, SHA President and the original acoustic & audio designer for NCC’s permanent exhibition gallery and Kimmel Theater, to help develop a solution to this challenging problem. Subsequent to the museum’s opening in 2003, Haas has maintained an ongoing consulting relationship with NCC to ensure that the facility’s quality of sound was either maintained or, in some cases, newly addressed.
Haas and his team at SHA proceeded to evaluate the existing conditions and determined that the reverberation time (the time it takes for an impulsive sound, like a handclap to disappear) of the existing space was around 10 seconds – over three times as long as a large cathedral! Given this condition, the solution would certainly not be trivial or inexpensive – especially since matching the existing aesthetics of the Hall was paramount.
After evaluating several solutions, SHA chose to recommend the application of a seamless, micro-porous acoustic plaster known as BASWA Phon to large triangular sections of the ceiling. Haas had successfully used BASWA Phon in a number of commercial and residential applications and was very confident in its acoustic performance and aesthetic character.
The projects first stage concentrated on the BASWA Phon treatment over the main event area, with the second stage further distributing additional material on sections throughout the other areas of the Hall. In January 2009, the first stage was installed. Along with previous upgrades that had been done to optimize the speech reinforcement audio system using a line array loudspeaker system from Renkus Heinz, the inclusion of the BASWA Phon sound-absorbing treatment has greatly improved the use of the Grand Hall for special events.