Holy Rosary Church: Bozeman, MT
"People can't get the Word if they can't hear the Word" - John Meyer of Meyer Sound
It's as simple as that. Yet it's not that simple implementing a sound system within the large, open, very reverberant spaces of this newly rebuilt old building. This was a welcomed challenge. The architectural firm "Think One" contacted us about Bozeman's Holy Rosary Catholic Church at the end of 2011. The whole town was noting the progress of this building; it's an iconic gateway building as you enter our historic downtown from the west. The massive remodel and expansion project was gracefully undertaken by Martel Construction. The "design committee" for the project envisioned a new ultra-clear, easy to use, and reliable sound system for the church. Poindexter's was initially hired to provide a "study" of the sound system, then to devise a design/installation plan and proposal for a new turn-key system. This included design drawings, pre-wire, installation, system tuning, instruction, follow-up service and required maintenance. It was imperative that the new system minimized the amount of visible "technology". Rising to the challenge, we relied upon our strong relationship with Meyer Sound, a world renowned leader in high-fidelity sound reinforcement systems. Together we collaborated on a system that delivered on all the goals outlined by the architects, design committee, and Father Leo, the parish's leader. "God needs to be heard," Fr. Leo remarked during an early meeting. Meyer was soon releasing their new ultra-compact MM-4XP speaker, so we borrowed a prototype demo system and quickly arranged a test listen for the team. The timing of this new product dovetailed perfectly with this project and our preliminary design. Meyer's MM-4XP is a 4" square "self powered" speaker optimized for voice reproduction. Like all Meyer speakers, the MM4-XP offers excellent coverage (pattern control) and an extremely flat frequency response from 135 Hz up to 16 kHz. These numbers indicate a working range optimized for "voice reproduction". It was as if the speaker was invented for this project; it's size and look delighted the architects. In order to "hide" the speaker system, we opted to carefully tuck 16 custom painted MM-4XP speakers behind the pilasters strategically around the sanctuary and naves (wings of the building). We were careful to align the small speakers within the archway detail that links the plaster pilasters. Two speakers were placed facing the alter; this was a last minute design decision made after listening to the sound of the room during quiet evenings, once the construction workers were off duty. This unconventional decision provided the "alter" with an independent "monitor system" for sound reinforcement. The idea helped to minimize the "delay" bounce that would be present in the room after sound was reflected off of distant, solid surfaces, such as the tall, curved ceilings and the large, flat back wall, then bounce back with a long delay to the alter area. Such a delay "bounce" could prove both annoying and terribly distracting to someone speaking or preaching from the alter, as syllables spoken would be returning to the speakers ears just as new words were ready to depart the speakers lips. This combination was a recipe for confusion. Adding the additional two "monitor" speakers proved a wise move in this situation; with them we were able to over power the sound of the delay with direct sound pointed down at the alter. The materials of the building include marble, tile, stone and plaster; there's nothing soft to absorb sound except when it's filled with people on Sundays, holidays and during special events.
We were able to confidently install this type of system with the help of Meyer Sound's "Meyer Acoustical Prediction Program" called MAPP. After importing the CAD drawing of the church into a computer running MAPP, we're able to virtually place any number of MM-4XP speakers (or any model Meyer makes) and a virtual microphone anywhere within the virtual building and make test measurements. The MAPP program quickly feeds the information to Meyer's super computer located in Berkley, CA via a web connection, and within a minute returns a series of graphical representations of the space that combine to show the consequences of our "virtual actions". The data provides us with sound pressure level per a given a mic. location, and coverage predictions for the space at a given frequency. In the slide show playing above, two images or "studies" of the main sanctuary are on display. Note the CAD drawing showing the layout of the main sanctuary with call-outs to the locations we opted to place 16 of the 18 MM-4XP speakers. The colorful red, yellow and orange image that follows is a "heat map" SPL (Sound Pressure Level) graphic that MAPP generates. Note the 10 speakers placed along the walls within the main sanctuary; this study shows each MM-4XP's predicted coverage pattern, taking into account the combination of speakers, room dimensions, speaker location, air temperature and humidity into consideration while playing a 1,000 Hz test tone - a common "center frequency" noise often used to measure a speaker's response within a space. As MAPP indicates, at this 1 kHz virtual tone the room is almost perfectly covered in color, which equates to even sound coverage. The red color indicates a "louder" volume level, yellow being less loud.The experience in the actual room with the sound system installed and properly adjusted is nearly identical to this accurate visual prediction. The height and placement angle of all 18 speakers throughout the building insure that they work together as a system to help distribute sound evenly throughout the church. Proper adjustment and time alignment of the system also comes into play.Our hope was to out-fox physics just a little. The huge reverberation time of this massive room was a very tall hurdle to to jump. We feel we cleared the bar using every trick we've learned, along with some excellent equipment, technology and advise from our friends at Meyer Sound. Through careful time alignment and slight system equalization we were rewarded with clarity of speech to almost every seat within the building. With this system we have individual control of each speaker in the following attributes: volume level, equalization (graphic and parametric), time delay, and phase. It's an extremely wonderful, flexible and powerful opportunity to have this much control over a system. Having the control is one thing, knowing how to utilize it is the other.
The next task was to go about capturing the voices with discrete, reliable, high quality microphones and electronics. We chose equipment by Sennheiser, who make great sounding wireless systems and microphones of all shapes and styles. The wired mics. were integrated to the "Ambo" and "Cantor" podiums that flank the alter. Father Leo requested a "wireless" microphone, as he enjoys zipping all around the church during his well attended weekend masses. Two special antennas were thoughtfully suspended high within the sanctuary; together they assure a strong signal from the wireless microphone systems currently in place. We have a single handheld and two wireless "belt pack" systems on the ready, all of which may be utilized throughout the large building with confidence. The wireless belt-pack systems were paired with DPA "over-the-ear" headset mics. The headset system allows Father Leo to use his hands while providing him with a comfortable high fidelity solution. The DPA mics. proved a much better solution over a traditional "lapel" type microphone that were in use previously. We solute Fr. Leo for embracing technology to better tell his stories and serve his parishioners. We needed every bit of quality we could muster from each component to help combat the acoustical spaciousness and challenge of this structure. Elegant and discrete "wired" microphones were placed on the "Ambo" and "Cantor" speaking podiums from which readers, guest speakers, and singers utilize during services. We added simple "mute" switches to these locations allowing Fr. Leo and others the ability to float between the wireless and wired systems with the flip of a switch.
At the heart of the system is an auto-mixer by Symetrix, programmed to control microphone levels, equalization, compression and limiting. This device also routes the audio signals to the hearing assist system and speaker system controller by Meyer, called a Galileo. Although this is a very high tech. system in the background, operating this system takes just 3 buttons on a wall mounted remote control. The three button control unit and it's LED display guide the user through a few simple control choices. The microphone volume levels may be adjusted to account for a soft or loud presenter. We've also programmed in a set of system "presets", which provide 3 basic choices: weekend mass, weekday mass, or system Off. When "weekend mode" is selected, each and every speaker is activated. When "weekday" mode is selected, the 10 speakers deployed to cover the large main seating section of the building are set to "mute" mode. Since no one is sitting in this area during weekday mass, there's no need to deliver sound to the entire building. Piping in sound to an unoccupied building with wooden pews causes further problems, diminishing speech intelligibility near the front of the room. Turning off the un-needed speakers helps to improve the sound quality for those sitting within the smaller "wings" of the church, which is where the week-day mass occurs, as attendance is much smaller. It's great to be able to make adjustments like this that go a long way to help improve the usability of a space, while also improving the experience for those attending a service. We've been on a quest for sonic intelligibility with this project since our first meeting. Ideally the church will add some "acoustical treatments" in the future. For now, everyone is happy, and the system has been working like a miracle.