Jack Covert,
AV Design, Orpheus Acoustics

Our Lady of the Angels Parish Pittsburgh, PA

For over 100 years the St Augustine Cathedral has overlooked the Allegheny River from along one of the steep, narrow side streets so characteristic of Pittsburgh. For the past 37 years since the change to English Mass [from Latin], the Congregation has not been able to understand the spoken word within this beautifully ornate Gothic Sanctuary. "You are the sixth sound contractor to attempt to resolve this problem" Father John Daya told me. "Fix it and you will go down in history, at least here".

St. Augustine Cathedral, Our Lady of the Angels Parish, Pittsburgh, PA

Father John contacted me because of my successful sound system design at the original St. Joseph's RC Church in York, Pa. two decades ago. I then designed and installed a sound system for the new, modern 800 seat Sanctuary built six years ago. Last year when Fr. John moved to Pittsburgh and was presented with the current sound situation at St. Augustine, he told me that he was confident that I would have a solution.

The building has a classic Cruciform design with an interior dome measuring a breathtaking 105-feet above the vertex. When you enter the Nave and speak, the low frequency reverberation is almost overwhelming. Though organ, choir, and solo vocal music sound wonderful, speech (at distances greater than 15 feet or so) is almost completely unintelligible.

Physical measurements were taken in order to build a 3-dimensional acoustic model of the Nave. Orpheus uses EASE acoustic modeling software for sound system design and performance prediction. EASE is the industry standard software package for acoustical modeling and auralization. I have had experience with all of the other packages out there and EASE is much more accurate and realistic.

Furthermore, I always measure the reverberation time (RT-60) and impulse time while on site for comparison with the computer model - to further insure accuracy." The RT-60 within the Nave at St. Augustine was measured at 5.74 seconds, averaged over 1-octave frequency bands.

The existing sound system consisted of twenty-two dual 4", omni-directional loudspeakers mounted throughout the Nave. Two large EV 15" 2-way cabinets were wall mounted flanking the Sanctuary (Chancel Platform). The omni-directional loudspeakers were spraying sound in every direction and their sound was further reflected by the myriad hard, reflective surfaces. msaking the wide coverage pattern and increased low frequency response of the EV loudspeakers introduced even more energy into a room that was not absorbing nearly enough sound. This random distribution of sound in a highly reverberant space obliterated speech intelligibility.

Linear Array Loudspeakers were the obvious choice for pattern control at the critical speech - intelligibility frequencies. However, the overpowering, low frequency din could not be tamed by acoustical treatment. Since the Nave had gone through an extensive renovation the previous year an additional goal of the sound system upgrade was to enhance the aesthetic qualities of the space. It was hopeful that this could be achieved by limiting the amount of sound equipment that was visible to the congregation; adding acoustical treatments or changing anything physically within this historic building was not an option. 44" high, Line Array Loudspeaker, factory painted to match the wall.

After building the EASE model and studying coverage cone patterns of different line array loudspeakers it was determined that moderately sized passive products would work very well, and the very tight budget could be realized. Many consultants and contractors today specify extremely expensive "steerable", loudspeaker devices or huge columns of small loudspeaker enclosures to resolve similar problems. The active line arrays and unsightly 9-foot "towers" of loudspeakers have their place, but I have yet to find a situation that could not be addressed using smaller passive devices. St. Augustine proved to be another project that supported this statement.

Six Linear Array columns, two measuring approximately 4 feet in height, and four roughly two feet in height, were selected to cover the Nave. This was based upon the native coverage cones at 2000 Hz. The loudspeaker were factory-painted to match the interior finish of the Church. Electronics include two Shure MX412C/S Pulpit and Lectern microphones, two TOA Password UHF Wireless lapel microphone systems, a Shure SCM-810 auto-mixer, a Shure P4800 DSP, a Crown CT-410 amplifier, Williams RF Assistive listening system, and re-use of their existing Rane MA-6 amplifier and Denon CD/Cassette Combo-deck. The entire system operates as a 70.7V distributed system with a dedicated amplifier for each loudspeaker. All of the loudspeakers within the Nave are digitally delayed and time aligned using the P4800. The results are clear intelligible speech at every listening position within the Nave. I carefully equalized the system to optimize critical speech frequencies, allowing intelligible speech to cut through the reverberant field. The low frequency din that is left adds a little warmth to the sound in the room. Aesthetics were improved by reducing the quantity of loudspeakers, painting them to match the walls, and carefully locating them for optimal performance and low visibility. Father John has reported nothing but rave reviews. "Finally, everyone in the Congregation is able to hear the mass. We are planning to renovate the other two churches in the Parish and will be calling upon Jack to provide sound system upgrades during the process."