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RCDD · Question #194

For design purposes, loudspeakers are rated for a measured sound pressure level (SPL) at:

The correct answer is A. 1 m (3.3 ft) from the loudspeaker with 1 watt of power input. The industry-standard loudspeaker sensitivity rating is defined as the SPL measured at 1 meter from the loudspeaker with exactly 1 watt of power input, allowing direct comparison across products.

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Question

For design purposes, loudspeakers are rated for a measured sound pressure level (SPL) at:

Options

  • A1 m (3.3 ft) from the loudspeaker with 1 watt of power input
  • B1 m (3.3 ft) from the loudspeaker with 2 watts of power input
  • C3 m (10 ft) from the loudspeaker with 1 watt of power input
  • D3 m (10 ft) from the loudspeaker with 2 watts of power input

How the community answered

(38 responses)
  • A
    71% (27)
  • B
    16% (6)
  • C
    8% (3)
  • D
    5% (2)

Why each option

The industry-standard loudspeaker sensitivity rating is defined as the SPL measured at 1 meter from the loudspeaker with exactly 1 watt of power input, allowing direct comparison across products.

A1 m (3.3 ft) from the loudspeaker with 1 watt of power inputCorrect

Loudspeaker sensitivity is standardized at 1W/1m - meaning 1 watt of input power measured at 1 meter distance - and is expressed in dB SPL. This universal reference point allows system designers to compare loudspeaker efficiency across manufacturers and accurately calculate required amplifier power and expected coverage levels during system design.

B1 m (3.3 ft) from the loudspeaker with 2 watts of power input

2 watts is not the standardized input level; using a higher wattage would produce a higher SPL reading that would not be comparable to ratings measured at 1 watt.

C3 m (10 ft) from the loudspeaker with 1 watt of power input

3 meters is not the standard reference distance; greater distance results in lower SPL due to the inverse square law, making the figure non-comparable to 1m-based ratings.

D3 m (10 ft) from the loudspeaker with 2 watts of power input

Neither 3 meters nor 2 watts match the standard; both deviations would yield a non-standard sensitivity figure unusable for design calculations.

Concept tested: Loudspeaker sensitivity rating standard (1W/1m)

Source: https://webstore.iec.ch/en/publication/1221

Topics

#loudspeaker sensitivity#SPL rating#speaker specification#1-watt 1-meter

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