CMP Acoustics and Recording Techniques 2 — Questions and Answers
Question 1: What is the primary purpose of a diffuser panel in a recording studio?
- Absorb low-frequency energy
- Scatter sound waves to reduce flutter echo (Correct answer)
- Block outside noise from entering
- Increase reverberation time
Correct answer: Scatter sound waves to reduce flutter echo
Diffusers scatter sound waves in multiple directions, breaking up flutter echo and standing waves without deadening the room.
Question 2: Which microphone pattern is best for isolating a single instrument on a loud stage while rejecting side bleed?
- Omnidirectional
- Figure-8
- Hypercardioid (Correct answer)
- Subcardioid
Correct answer: Hypercardioid
Hypercardioid patterns have the narrowest front pickup lobe and strong rear rejection, making them ideal for high-isolation scenarios.
Question 3: What does 'critical distance' refer to in room acoustics?
- The maximum distance between two parallel walls before flutter echo occurs
- The point where direct and reverberant sound levels are equal (Correct answer)
- The minimum distance a microphone must be from a source
- The distance at which bass buildup becomes problematic
Correct answer: The point where direct and reverberant sound levels are equal
Critical distance is where the direct sound field and the reverberant field have equal energy, influencing microphone placement decisions.
Question 4: A recording engineer notices a 'comb filtering' artifact in a guitar track. What most likely caused it?
- Too much compression on the signal
- Two slightly delayed versions of the same signal being combined (Correct answer)
- A ground loop in the signal chain
- Excessive high-frequency EQ boost
Correct answer: Two slightly delayed versions of the same signal being combined
Comb filtering results from mixing a signal with a slightly delayed copy of itself, creating alternating peaks and notches across the frequency spectrum.
Question 5: What is the recommended sample rate for recording audio intended for high-resolution music distribution?
- 22.05 kHz
- 44.1 kHz
- 88.2 or 96 kHz (Correct answer)
- 192 kHz only
Correct answer: 88.2 or 96 kHz
88.2 kHz or 96 kHz are standard high-resolution sample rates that capture extended frequency content beyond CD quality for premium distribution.
Question 6: When using a large-diaphragm condenser microphone on a vocalist, where should the engineer place it to minimize plosives?
- Directly in front of the lips at 0°
- Above the mouth angled slightly downward (Correct answer)
- Below the chin angled upward
- At 90° off-axis to the right
Correct answer: Above the mouth angled slightly downward
Positioning the mic above and angled down keeps it off the direct path of expelled breath from plosive consonants while maintaining a natural sound.
Question 7: What does 'proximity effect' do to a directional microphone's frequency response as it moves closer to a sound source?
- Attenuates high frequencies
- Boosts low-frequency output (Correct answer)
- Increases mid-range sensitivity
- Creates a null at the rear
Correct answer: Boosts low-frequency output
Proximity effect causes directional microphones to exhibit increased bass response as the source distance decreases, due to the pressure gradient principle.
CMP Acoustics and Recording Techniques 2
What is the primary purpose of a diffuser panel in a recording studio?