Free Music & Audio Advice Microphone Placement Techniques Questions and Answers 1

Question 1

When recording a source with two microphones, what is the primary purpose of the 3:1 rule?

Accepted Answer

To minimize phase cancellation and comb filtering between the microphones.

Answer

The 3:1 rule is a guideline used to reduce phase cancellation when using multiple microphones on a single or multiple sources. It states that the distance between two microphones should be at least three times the distance from the first microphone to the sound source. This ensures that the sound arriving at the second microphone is significantly lower in level, minimizing destructive interference (comb filtering) when the signals are combined.

Question 2

An audio engineer is setting up a Blumlein pair to record a string quartet. Which of the following microphone configurations is correct for this technique?

Accepted Answer

Two bidirectional (figure-8) microphones with their capsules coincident and angled 90 degrees apart.

Answer

The Blumlein pair technique specifically requires two bidirectional (figure-8) microphones. The capsules are positioned as close together as possible (coincident), often with one directly above the other, and angled at 90 degrees to each other. This setup captures a highly realistic stereo image along with the room's ambiance.

Question 3

What are the standard specifications for the ORTF stereo microphone technique?

Accepted Answer

Two cardioid mics at a 110-degree angle, capsules spaced 17 cm apart.

Answer

The ORTF technique, developed by the French broadcasting organization, has very specific parameters: two cardioid microphones are angled at 110 degrees, with their capsules spaced 17 cm apart. This 'near-coincident' arrangement is designed to mimic the spacing and angle of human ears, capturing both intensity and timing differences to create a natural stereo image.

Question 4

A recording engineer notices that a close-miked male vocal track sounds overly bassy and 'muddy'. Which microphone phenomenon is the most likely cause?

Accepted Answer

Proximity Effect

Answer

The proximity effect is an increase in low-frequency response when a directional microphone (like a cardioid) is placed very close to a sound source. This phenomenon is often the cause of a 'boomy' or 'muddy' sound in close-miking situations, especially on vocals. Moving the microphone slightly farther away can reduce this effect.

Question 5

When using a coincident pair (X/Y) technique to record an acoustic guitar, what is the primary advantage regarding phase?

Accepted Answer

It minimizes phase issues because the capsules are as close as possible.

Answer

In an X/Y or coincident pair setup, the capsules of two directional microphones are placed as close to each other as possible, typically at a 90-degree angle. Because of this close proximity, sound arrives at both capsules at virtually the same time, which significantly minimizes phase cancellation issues that can occur with spaced microphone techniques.

Music & Audio Advice Practice Test

Music & Audio Advice Practice Test

Free Music & Audio Advice Microphone Placement Techniques Questions and Answers 1