Audio systems: A woofer, which is designed to reproduce low-frequency sounds, should be connected to the input through which type of filter?
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Alow pass filter
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Bhigh pass filter
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Cband pass filter
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Dband stop filter
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Enotch filter
Answer
Correct Answer: low pass filter
Explanation
Introduction / Context:Woofers are specialized loudspeakers designed to handle bass and sub-bass frequencies, typically below 200 Hz. To ensure they receive only the appropriate frequency range, crossover filters are applied.
Given Data / Assumptions:
- Woofer frequency range: ~20 Hz to 200 Hz.
- Input audio contains the full frequency spectrum.
- A filter is required to ensure only low frequencies reach the woofer.
Concept / Approach:A low pass filter allows low-frequency signals to pass while attenuating higher-frequency components. This ensures the woofer does not attempt to reproduce mid or high frequencies, preventing distortion and ensuring fidelity.
Step-by-Step Solution:
Full audio range is split: woofer (lows), midrange speaker (mids), tweeter (highs).Crossover circuit assigns ranges using filters: low-pass for woofer, band-pass for midrange, high-pass for tweeter.Therefore, correct filter for woofer = low-pass filter.Verification / Alternative check:Commercial audio crossover designs confirm woofers are fed via low-pass sections tuned at crossover frequencies (100–200 Hz in home audio; 80–120 Hz in car systems).
Why Other Options Are Wrong:
High-pass: used for tweeters.Band-pass: used for midrange drivers.Band-stop / notch: used to eliminate narrow bands of interference, not for speaker crossovers.Common Pitfalls:
Believing woofers can handle all audio input; while physically possible, distortion and inefficiency result without filtering.Final Answer:
low pass filter