Ceiling speakers distribute sound directly above the listener, unobstructed, from relatively low ceilings over large areas. When installed with adequate spacing and sufficient power, the best-quality models provide even sound coverage and adequate frequency response for both speech and music.
They are usually installed recessed in false ceilings, although there are models for surface installation.
Generally, they do not have a back box; they use the space between the ceiling and the false ceiling for bass reinforcement. However, there are models with a built-in box, usually with better performance. The usual mounting height is between 2.5 and 4 m. For higher ceilings, more powerful models should be installed or, depending on the room, another type of speaker, such as speakers or acoustic spheres.
High-performance models are usually more powerful, two-way, and have a better frequency response. Some models are of similar quality to equivalent two-way wall speakers, but are ceiling-mounted.
These speakers are suitable for installation in rooms with noise levels below 70 dB SPL, such as those found in office buildings, restaurants, hotels, shops, banks, cinema and theatre lobbies. They are also suitable for warehouses and supermarkets with low ceilings, although the noise level is slightly higher (75 dB SPL).
Mounting
Different quick mounting methods for ceiling speakers (arch, springs, claws, etc.)
Distribution recommendations
Under conditions such as those mentioned above, the installation recommendation would be:
- In hallways, one speaker is installed every 5 to 6 m
- In large areas, each speaker covers between 25 and 36 m2
Exercise
Sound system for an office with 30 m of hallways, a 200 m2 common room, and four 45 m2 offices. The measured noise level is 65 dB, and the false ceilings are 3 m high.
NUMBER OF SPEAKERS
- Corridors (30 m): 30/6 = 5
- Common room (200 m2): 200/36 = 5.55 (~6) Offices (4 of 45 m2): 46/36 = 1.25 (~1)
- In the offices, 5 speakers will be installed in the hallway, 6 in the room, and 1 in each office, for a total of 15 speakers.
ACOUSTIC CALCULATIONS
- Attenuation at listener height (1.5 m): 20·log(3 - 1.5) = 3.52 dB SPL
- Required SPL 1 W, 1 m (SNR = 15 dB): 65 + 3.52 + 15 = 83.52 dB SPL
- Therefore, a speaker with a maximum SPL > 83.52 dB SPL can be used.
