acoustics case study iit roorkee church

IIT-R Church: Acoustics and lightings

Aniruddh Jain 10110006

Acoustical challengesCathedrals incorporate a variety of spaces and uses in addition to worship, including residential, retail, dining, conference and meeting, social and fellowship, and learning

Worship and liturgy needs to be respected and celebrated.

Should be quiet, conducive to meditation and tranquility

Significant community/regional/national impact

The challenge of accommodating the spoken word (e.g. sermons, lectures, presentations) and music in a cathedral is significantly more difficult than a typical church project. a live to very live, reverberant environment

Because of the size huge interior volumes lacking “close-in” sound reflecting surfaces, the acoustical design challenges are exacerbated, more so than the technical calculations may lead one to believe.

Acoustical challenges

Transparent acoustic design and audiovisual systems (visually and operationally) is desired by the architects, clients and end users.

Iconic architectural design, especially when selected via design competition, is difficult to change to any significant effect.

Architectural design has a tendency to continue throughout the project and sometimes into construction.

Expectations are high for all aspects of the project.

BASIC REQUIREMENTS1. Lively natural acoustics that support and enhance the spoken and sung responses of the assembly.

2. An acoustic environment that gives an audible impression of the presence of others, clearly conveying the experience of public worship.

3. Suitable locations and spatial configurations for the primary sound sources.

4. Good sound isolation to prevent the intrusion of distracting sounds during worship or meditation and to allow privacy and confidentiality where needed.

5. Adequate control of noise produced by building systems within the church such as HVAC, plumbing, and lighting.

6. A high-quality sound reinforcement system

1

Provide a reverberation period of at least 2 to 3 seconds

2

Minimize the amount of sound absorbing materials. In all cases, sound absorbing materials must not be located near the important sources of sound: the assembly, the music ministry, and the presiders and readers. Since all of these sound sources are at floor level, floors cannot be carpeted and pews cannot be covered with upholstery or cushions.

3Provide sufficient room volume to allow the natural development and support of sound. A volume of 300-400 cubic feet per seat is recommended for churches with seating capacities up to about 800 seats. Larger churches may require greater volume, but smaller churches should not fall substantially below this range. In providing sufficient room volume for acoustics, height is a more important factor than floor area.

4

Provide properly oriented, hard-surfaced materials around sound sources. All surfaces (including floors, walls, and ceilings) near and around presiders, cantors, readers, musicians, and the assembly must have hard surfaces.

5

Avoid or minimize the use of lightweight surface materials such as gypsum board or thin wood panels. If wood paneling is desired, and if it occupies a large area, it should be attached directly over solid, massive structural materials. Do not use suspended acoustical ceilings.

6

In designing new churches, avoid the use of architectural elements that cause echoes, particularly from rear walls. In renovations, existing echoes should be eliminated. In all cases, the preferred method for preventing echoes is to use irregularly shaped surface. Sound absorptive treatments are to be used only as a last resort and to the minimum extent needed.

7Avoid the use of curved surfaces where they might tend to focus or concentrate sound in a confined area. There are many exceptions and extenuating factors in this recommendation. Allowances should be made for traditional forms such as rounded apses, barrel vaults, etc., and for architectural creativity—but not to the detriment of acoustics. Here, too, surface irregularities can sufficiently reduce focusing.