When a loudspeaker generates 82 dBSPL at 12 feet, what would the level be at 27 feet?

When a loudspeaker generates 82 dBSPL at 12 feet, what would the level be at 27 feet?

• A. 70 dBSPL
• B. 75 dBSPL
• C. 55 dBSPL
• D. 80 dBSPL

Answer: (B)

To determine the sound pressure level (SPL) of a loudspeaker as the distance from it changes, we can apply the inverse square law of sound, which states that sound level decreases by approximately 6 dB for every doubling of distance from the source. In this scenario, the loudspeaker generates 82 dBSPL at a distance of 12 feet. We want to find the level at a distance of 27 feet. First, we note the distance change from 12 feet to 27 feet. To clarify this in steps: 1. From 12 feet to 24 feet (double the distance), we expect a decrease of 6 dB. 2. At 24 feet, the SPL would theoretically be 82 dBSPL - 6 dB = 76 dBSPL. 3. Then, moving from 24 feet to 27 feet is a smaller change. Since this is less than doubling the distance, the decrease will be less than 6 dB. A 3-foot increase does not allow for a significant drop compared to a doubling of distance. We can estimate that instead of a full 6 dB decrease for doubling, we could go with a decrease of approximately 2 dB (

To determine the sound pressure level (SPL) of a loudspeaker as the distance from it changes, we can apply the inverse square law of sound, which states that sound level decreases by approximately 6 dB for every doubling of distance from the source.

In this scenario, the loudspeaker generates 82 dBSPL at a distance of 12 feet. We want to find the level at a distance of 27 feet.

First, we note the distance change from 12 feet to 27 feet. To clarify this in steps:

1. From 12 feet to 24 feet (double the distance), we expect a decrease of 6 dB.

2. At 24 feet, the SPL would theoretically be 82 dBSPL - 6 dB = 76 dBSPL.

3. Then, moving from 24 feet to 27 feet is a smaller change. Since this is less than doubling the distance, the decrease will be less than 6 dB.

A 3-foot increase does not allow for a significant drop compared to a doubling of distance. We can estimate that instead of a full 6 dB decrease for doubling, we could go with a decrease of approximately 2 dB (