Horn speakers are the most suitable for achieving high sound pressure with minimal amplification power. However, their frequency response is poor, making them unsuitable for quality music reproduction. The level of distortion is also higher than with other types of speakers.
They include an anchor for wall or ceiling installation and are designed for outdoor installations.
Their sensitivity is very high (more than 100 dB 1 W 1 m). With a very low amplification cost, they can provide sound reinforcement for large areas.
Properly installed, and thanks to their narrow bandwidth, focused on the center frequencies, they achieve high intelligibility in large rooms or areas.
In very noisy environments (90 dB), they are the only loudspeakers capable of guaranteeing the intelligibility of the transmitted message.
Installed at an appropriate height to avoid damaging listeners nearby (> 4 m), they reach long distances with a good sound pressure level (40-50 m, depending on the noise level).
These are the loudspeakers of choice for factories, workshops, industries, outdoor areas of any facility, beaches, pedestrian areas, gas stations, and more.
Distribution recommendations
Under conditions such as those mentioned above, the installation recommendation would be:
- For linear outdoor sound systems (streets), every 20 to 30 m (h = 5 m).
- For general outdoor sound systems, a cluster of 4 loudspeakers at h = 6 covers an area of 5,000 m2.
- For indoor sound systems in noisy environments, each loudspeaker can cover areas of 500 to 600 m2 (h = 5 m).
Exercise
To equip a 100 m x 100 m warehouse with sound, with columns every 10 m and a ceiling height of 8 m, although the speakers will be installed at a distance of 5 m. The ambient noise level is 80 dB.
NUMBER OF SPEAKERS
- According to the recommendation, one every 600 m2 : 100•100/600 = 16.67 ~ 16 speakers
- If the column layout allows it, a good solution would be 4 groups (clusters) of 4 speakers in a cross, at the coordinates (25,25), (25,75), (75,25) and (75,75)*
- *(75,75) means, in plan, 75 m horizontally and 75 m vertically.
ACOUSTIC CALCULATIONS
- Speaker-to-furthest listener distance: d2 = (50/2)2 + (50/2)2; d = 25 m
- NOTE: The speaker-listener height can be neglected in the calculations.
- Attenuation at listener height: 20 log 25 = 27.96 dB SPL.
- Required SPL 1 W, 1 m (SNR = 15 dB): 80 + 27.96 + 15 = 122.96 dB SPL.
- Therefore, a speaker with a maximum SPL > 122.96 dB SPL can be used.
