The following are some of the principles and factors that are important for good acoustical conditions.
Site selection and planning
The site selection must be carried out with care. It must be ensured that the site selected is located in a quite surrounding otherwise the cost of construction may escalate due extensive application of sound insulation. Air conditioned buildings must be adequately insulated for elimination of compressor and grillage noise.
Dimensions
The size should be fixed in relation to the number of people to be accommodated in the room and the type and intensity of the sound that has to produced in the room.
Shape
The shape of the hall/auditorium is extremely important in the acoustical design since it is the governing factor in correcting defects like echoes, sound foci, dead spots, sound, shadows, etc. The shape of the hall is to be geometrically arranged in view of better audibility.
Seats and seating arrangements
The seats should be arranged in concentric arcs of circles drawn with the centre located as much behind the centre of the curtain line as its distance from the auditorium rear wall.
For good visibility and listening conditions, the successive rows of seats must be placed higher than the preceding ones.
Treatment of interior surfaces
The treatment of interior surfaces play an important role in acoustical design. The ceilings and walls should provide favourable reflections to reinforce that reaches the rear part of the auditorium.
Reverberation and sound absorption
Certain amount of reverberation is necessary to accord richness to the music but too much reverberation is undesirable. Reflection surfaces must be so designed to aid distribution of sound and must be earmarked for absorption materials.
