CEA Speaker Systems & Amplification 2

Question 1

A speaker has a sensitivity of 100 dB SPL (1W/1m). What SPL is produced at 1 meter when driven with 100 watts?

Accepted Answer

120 dB

Answer

SPL = sensitivity + 10×log10(power): 10×log10(100) = 20 dB, so 100 + 20 = 120 dB SPL.

Question 2

What is the primary sonic advantage of bi-amping a two-way speaker system?

Accepted Answer

Each amplifier handles only its frequency band, reducing intermodulation distortion

Answer

With bi-amping, separate amplifiers handle high and low frequencies independently, so intermodulation between bass and treble signals is eliminated and each amp operates with greater headroom.

Question 3

Reversing the polarity of one speaker in a stereo pair most noticeably causes:

Accepted Answer

Bass cancellation and a diffuse, unfocused stereo image

Answer

Out-of-phase speakers cause their long-wavelength bass frequencies to cancel, and the stereo image spreads unnaturally rather than focusing in the center.

Question 4

How does a ported (bass reflex) cabinet differ from a sealed cabinet in terms of low-frequency behavior?

Accepted Answer

Its tuned port extends low-frequency output below the driver's natural resonance

Answer

The tuned port acts as a Helmholtz resonator, reinforcing bass output at and below the driver's resonant frequency and extending usable low-frequency response.

Question 5

What does the horizontal dispersion specification of a loudspeaker describe?

Accepted Answer

The angular range over which the speaker maintains consistent frequency response in the horizontal plane

Answer

Horizontal dispersion is the angular coverage (e.g., ±60°) within which frequency response remains relatively flat, which is critical for determining audience coverage in live sound.

(CEA) Certified Audio Engineer Practice Test

(CEA) Certified Audio Engineer Practice Test

CEA Speaker Systems & Amplification 2