Reverb hurts a worshipful experienceAudio/Visual, TECHNOLOGY Thursday, November 1st, 2012
By Bobbie Bennett
Many modern churches have similar architectural designs: square or rectangular spaces. This may be ideal from an architectural standpoint, but it is not ideal for acoustics. In a recording studio, where the structure is built specifically to satisfy acoustical needs, rooms are built with angled walls, no parallel walls, and the hard, reflective surfaces are “treated” with absorbent materials to reduce sound wave reflections.
Sound waves gradually lose strength as they travel distance and eventually die out, like water waves do after a stone is thrown into a pond. If a wave encounters a hard surface before it dies out, it will be bounced off and be sent in a different direction. Imagine slapping water against the wall of a bath tub.
A troublesome room
Parallel walls create what are called standing waves. Standing waves occur when a sound wave gets trapped between the parallel walls and bounces back and forth repeatedly, cycling once each time, until it eventually dies out. The resulting sound is displeasing to the ear. Compound that with other excessive reflections off of the hard walls and you are left with a troublesome room for performance audio. Since knocking down the walls and reconstructing the room is not an option for most churches, acoustical treatment can be a great solution.
Grace Church in Longwood, FL, is located at the corner of a strip mall. Like many of today’s churches, the sanctuary is a giant square room with three sets of hard, highly reflective parallel walls. Grace Church smartly plays to the corners of the room — the stage is set diagonally in the corner on one side, therefore facing the opposing corner, not a flat wall, reducing slap back.
Abby Dolbear, music pastor at Grace Church, contacted our firm to assess the room. She explained that even when the system was loud, people were still complaining that they could not understand the vocals. Even speaking without mics or speakers turned on, the room was very noticeably “live” with a lot of reverberation (the repetitive reflection of sound waves) and slap back echo. You can imagine the impact when the pastor was mic’ed for a sermon. Dolbear knew acoustics were the problem and wanted to make it right.
Reverb is an important part of the worship service, when it is used effectively. The room cannot be completely deadened by acoustical treatment or the members of the congregation will feel isolated, negatively impacting the worship experience, but it cannot be so lively that it degrades the intelligibility of spoken word and sung lyrics coming from the stage.
Keeping this in mind, our firm suggested a room treatment with fiberboard panels covered in fabric, fire treated and rated, scientifically placed so that sound is absorbed and diffused by the proper amount and so that the room still remains aesthetically pleasing to the eye.
After the acoustical treatment was complete, Grace Church decided that they would proceed with an improvement of the electronics. Acoustics should be addressed first, before taking a look at the electronic equipment. You can have great equipment in a bad room and the room will still sound bad; put great equipment in a great room and the results will be fantastic.
A small line of carefully placed dB Technologies speakers were flown on either side of the stage, paired with Turbosound sub woofers. Special attention must be given to the directionality of all speakers in a space in order to avoid over exposure or dead spots. Matching the dispersion pattern of the speaker system to the area occupied by the congregation is always desirable.
An Allen & Heath iLive digital console was also installed. With effective use of dynamic processors such as gates and compression, an engineer can have complete control of the sound, further improving upon the room acoustics.
After the install was completed, Dolbear notes that the congregation was satisfied with the noticeable differences. “The dispersion of the sound has been amazing. You can walk the entire auditorium and it is the same,” she says.
Bobbie Bennett works in sales and marketing for Atlantic Professional Audio, Altamonte Springs, FL. www.atlanticproaudio.com
Avoid sound ‘leaks’ into the church’s neighborhood
Today, new environmental noise pollution laws are impacting churches, as well as clubs and concert venues, and as Sound Pressure Levels (SPL) are being implemented in worship settings, “sound is ‘leaking out’ into the neighborhood,” says Donnie Haulk, president and CEO of AE Global Media, Charlotte, NC.
“In some cities and states this leakage is called noise pollution and ordinances are starting to be written and enforced. Designing your building to be able to both absorb and keep your worship in your building is becoming a great consideration during the design process. And for existing spaces, acoustic remodels are being required to keep the worship in the building,” Haulk says.
Leakages can occur within the church building as well, as when a dynamic youth service elsewhere in the facility bleeds into the main service.
“The use of acoustic blocking walls in the worship facility along with being mindful of people flow and ministry programming can be used to assure this isn’t an issue for your ministry,” Haulk says. “The location and design of these rooms need to be mindful of the ministry application and relative location to the main worship space.” AE Global Media works extensively with churches around the world with live productions, broadcasting, webcasting, performance acoustics and media technologies.
Haulk says that another consideration is the “noise floor” in the worship space and the impact of the HVAC system on worship. “HVAC has major impact on how quiet a room can ultimately be,” he says. “The lower the noise floor in a worship space, the higher the dynamic range can be without having to be too loud or approach the threshold of pain to achieve great dynamics.”
A church’s acoustics can be redone to allow for greater ministry impact, says Haulk. “Often as worship styles change, you are required to re-address the architecture needed to implement the new worship music or art. Most buildings are capable of being upgraded.” Haulk gets many questions on acoustics:
Can we modify our acoustic environment to enhance the worship experience?
It is possible to “re-tune” a room with either mechanical or electrical acoustic treatments. Your required worship style and desired sound pressure level will determine how and where the room should be treated. It is recommended that the style of worship and SPL be determined before the building is built and then design the appropriate worship space for the ministry.
What impact do acoustics have on intimacy?
Intimacy, as defined in worship, is the ability for the parishioner to be able to feel as if the minister is able to make a direct connection to him or her during the ministry time. To design an effective worship environment takes a clear understanding of the type/style of ministry being delivered and is impacted greatly by architecture style, volume of space, natural and generated light, color, amplified sound and acoustics.
To achieve intimacy between the minister and the congregant one must be able to achieve a 1.2 to 1.4 second delay time in the vocal frequencies.
And have the sound to listener be perceived that the minister is physically close to the listener.
With an audio system design that lets the minister be able to communicate at vocal levels that would be normally used in a small room. In other words, the system must allow the minister to have the option to speak at a normal or low speech level, not raising his or her voice, while still achieving clarity in all vocal frequencies.
A sound system saga about longevity
A common question Richard A. Honeycutt is asked when designing a sound system for a church is how long the system will last. Dr. Honeycutt is principal consultant with EDC Sound Services, Lexington, NC. “Let’s examine this question by using a real-life example,” he suggests.
The First Baptist Church of Lexington, NC, founded in the late 1800s, moved into its current building in 1954. At that time, pastors prided themselves on projecting their speech so well, and enunciating so clearly, that no sound system was needed, so none was installed, except for two pulpit mics feeding a line amplifier for the local radio station broadcast.
However, after two years, the first sound system was installed: a four-channel mixer-amplifier, a compressor, two speakers built into the front walls, and two dynamic mics. The electronics for this entire Altec Lansing system were mounted in a closet external to the sanctuary, he says.
“This system served well for speech amplification, but in the 1970s, the music director wanted to amplify soloists and sometimes the choir; and the percentage of hearing-challenged listeners had increased. A new sound system was mounted in a custom-made roll-top cabinet in the balcony. It consisted of a 12-channel Electro Voice mixer, a Sunn power amplifier, a custom-built center speaker cluster, and new Electro Voice microphones,” Honeycutt says.
Choir pickup was accomplished using two E-V RE10 mics, each mounted in a foam “mouse,” a device allowing the mic to be placed on the floor in front of the choir, isolated from floor thumps. The resulting mic arrangement was not visually intrusive, and was free from the midrange frequency response irregularities caused by floor reflections.
Replacing the left-and-right pulpit mics by a single central one improved gain-before-feedback. The central speaker evened out sound coverage throughout the sanctuary.
During a major sanctuary renovation, the sound system was upgraded again. This happened in two stages over a period of about five years.
A computer was added to provide digital recording capability of major events. The old telephone-line transmission system that sent the signal to the radio station was replaced, reducing lightning vulnerability.
Into modern times
Late in 2011, in order to improve intelligibility in the sanctuary, the graphic equalizer and compressor were replaced. The wireless mics were replaced; the cassette recorder was retired — all services began to be digitally recored — and a new EZDupe CD duplicator was purchased.
Throughout these chronicles, the sound system was never replaced because of failure or being “worn out.” All changes were upgrades needed because of changing requirements to support an evolving worship style, and in order to take advantage of new technology.
So the answer to “How long will my new sound system last?” is probably “It doesn’t matter,” Honeycutt says. “Your needs and technology improvements will most likely dictate an upgrade before your new system fails.”