I recently had the opportunity to assist a local contractor in the final calibration of a line array system for a reverberant Catholic monastery.

A small section of rural southern Indiana has a dense Roman Catholic population of predominantly German descent. A number of traditional church buildings dot the landscape - most of which are very old and very reverberant. Buddy Ward is the local sound expert (a long time TEF user). He also owns and operates a frill-line music store in the area. Buddy never misses an opportunity to demonstrate to the locals that speech intelligibility can exist in a structure designed for traditional music and worship. He has become somewhat of a “line array evangelist” who can boast of some truly remark able results in these traditional structures.

The St. Meinrad monastery is a beautiful structure that is over 100 years old. Preservation of the aesthetics of the environment was a key part of the project.

The space we were working in has an RT in excess of 6 seconds at 2 kHz. The new sound system consists of four Intellivox line arrays placed at strategic locations throughout the room. While the ears are a wonderful tool for aiming such systems, they grow tired with use and cannot document the performance of the system. We augmented the listening process with %Alcons measurements performed on a Goldline TEF2O. The measurements clearly showed when we were in the main lobe of the line array (Figures 2-4), as evidenced by improved %Alcons, a shorter Early-Decay Time (EDT) and improved direct-to-reverberant ratio (ED-ER). This was indeed a “text book” case that supported what we feel we understand about speech intelligibility.

Fig. I - The diagram shows the mic positions used for each %Alcons measurement made in the visitor’s gallery.