Music & Audio Advice Microphone Selection and Placement Questions and Answers 1 — Questions and Answers
Question 1: A recording engineer wants to capture the detailed nuances and high-frequency content of a fingerpicked acoustic guitar in a studio setting. Which type of microphone is generally the most suitable choice for this application?
- Dynamic microphone
- Ribbon microphone
- Small-diaphragm condenser microphone (Correct answer)
- PZM (Pressure Zone Microphone)
Correct answer: Small-diaphragm condenser microphone
Small-diaphragm condenser microphones, like the Shure SM81 or Neumann KM 184, are highly favored for recording acoustic guitars due to their excellent transient response, wide frequency range, and ability to capture high-frequency detail with accuracy. Dynamic mics are more suited for high SPL sources like guitar amps, and ribbon mics tend to have a warmer, darker character, which might not be ideal for capturing bright nuances. PZM mics are typically used for capturing room ambience or conference audio.
Question 2: When recording a vocalist, moving a directional microphone (like a cardioid) very close to the sound source results in an increase in low-frequency response. What is this phenomenon called?
- Phantom power effect
- Doppler effect
- Proximity effect (Correct answer)
- Comb filtering
Correct answer: Proximity effect
The proximity effect is the term for the increase in bass or low-frequency response when a directional microphone is moved closer to a sound source. This is a characteristic of pressure-gradient (directional) microphones and does not occur with pressure-operated (omnidirectional) microphones. It is often used creatively by vocalists and announcers to add warmth or weight to their voice.
Question 3: An audio engineer is tasked with recording a large symphony orchestra and wants to achieve a wide, spacious, and natural stereo image. Which of the following stereo microphone techniques is specifically designed for this purpose, typically utilizing three omnidirectional microphones on a T-shaped bar?
- X-Y (Coincident Pair)
- ORTF (Near-Coincident Pair)
- Blumlein Pair
- Decca Tree (Correct answer)
Correct answer: Decca Tree
The Decca Tree is a classic stereo miking technique developed at Decca Studios specifically for recording orchestras. It traditionally uses three omnidirectional microphones (often Neumann M 50s) arranged on a T-shaped bar suspended above the conductor's position to capture a wide and detailed stereo image with a solid center.
Question 4: In a live performance setting with high stage volume from monitors and other instruments, a vocalist needs a microphone that provides maximum rejection of sound from the sides and rear. Which polar pattern would be the most effective choice?
- Omnidirectional
- Supercardioid (Correct answer)
- Cardioid
- Figure-8
Correct answer: Supercardioid
A supercardioid polar pattern offers the most rejection of sound from the sides (at 120-126 degrees off-axis) compared to a standard cardioid. While it does have a small lobe of sensitivity to the direct rear, its overall directionality is tighter, making it excellent for isolating a sound source and minimizing feedback in loud environments. Omnidirectional mics pick up sound from all directions, and Figure-8 mics pick up from the front and rear, making them unsuitable for this scenario.
Question 5: A recording engineer wants to capture both the low-end 'thump' and the high-end 'click' of a kick drum. A common two-mic technique involves placing one microphone inside the drum focused on the beater and another microphone just outside the resonant head's port hole. What is the primary purpose of the microphone placed inside, aimed at the beater?
- To capture the fundamental low-frequency resonance of the drum shell.
- To primarily capture the attack and high-frequency 'click' of the beater. (Correct answer)
- To pick up the sympathetic vibrations from the snare drum.
- To capture the overall ambient sound of the drum kit.
Correct answer: To primarily capture the attack and high-frequency 'click' of the beater.
Placing a microphone inside a kick drum and pointing it toward the beater is a standard technique to capture the attack, or the 'click,' of the beater hitting the drum head. This placement emphasizes the transient and higher-frequency components of the sound, which can then be blended with a second microphone placed outside the drum that captures more of the low-end body and resonance.
Question 6: Which of the following stereo miking techniques relies on differences in both timing (phase) and intensity (level) to create its stereo image, by spacing two cardioid microphones 17cm apart at a 110-degree angle?
- X-Y Technique
- ORTF Technique (Correct answer)
- Spaced Pair (A/B)
- Mid-Side (M-S)
Correct answer: ORTF Technique
The ORTF technique, developed by the French broadcasting organization, is a near-coincident pair method. It specifies placing two cardioid microphones with their capsules spaced 17cm apart and angled at 110 degrees. This configuration creates stereo information from both the time-of-arrival differences (phase) due to the spacing and the intensity differences (level) due to the angle and polar patterns, often resulting in a wide and natural-sounding stereo image.
Music & Audio Advice Microphone Selection and Placement Questions and Answers 1
A recording engineer wants to capture the detailed nuances and high-frequency content of a fingerpicked acoustic guitar in a studio setting.
Which type of microphone is generally the most suitable choice for this application?