CEA Recording Techniques & Equipment 3

Question 1

In multi-microphone recording, what is 'phase cancellation' and how is it typically identified?

Accepted Answer

Frequency suckouts caused by time-offset signals from multiple microphones summing destructively

Answer

Phase cancellation occurs when two microphone signals with time offsets (from different distances to the source) combine and destructively interfere at certain frequencies, creating thinness or hollow-sounding recordings. It is identified by audible frequency cancellations when channels are summed.

Question 2

What is the '3:1 rule' in multi-microphone recording?

Accepted Answer

The distance between two microphones should be at least three times the distance from each microphone to its source to minimize phase issues

Answer

The 3:1 rule states that for two microphones recording different sources, the distance between the microphones should be at least three times the distance of each mic to its respective source. This reduces phasing artifacts when the signals are combined.

Question 3

What is the function of 'phantom power' in a recording setup?

Accepted Answer

It provides 48V DC through the microphone cable to power active electronics in condenser microphones and active DI boxes

Answer

Phantom power supplies +48V DC via the balanced microphone cable (XLR pins 2 and 3) to power the internal electronics of condenser microphones and active DI boxes. It is called 'phantom' because it travels on the same conductors as the audio signal without interference.

Question 4

What is 'overdubbing' in a multi-track recording context?

Accepted Answer

Recording additional tracks over previously recorded material while listening back to the existing tracks

Answer

Overdubbing is the process of recording new audio tracks in synchronization with tracks already recorded. The performer listens to the playback via headphones while recording, allowing parts to be added layer by layer in a multi-track session.

Question 5

In acoustic recording environments, what does 'live end, dead end' (LEDE) room design refer to?

Accepted Answer

A room design where the front (live end) has reflective surfaces and the rear (dead end) is heavily treated with absorption

Answer

LEDE design places the speaker wall (front, 'dead end') with heavy absorption to eliminate early reflections at the listening position, while the rear ('live end') uses diffusive surfaces to provide a sense of spaciousness and envelopment without coloring early reflections.

(CEA) Certified Audio Engineer Practice Test

(CEA) Certified Audio Engineer Practice Test

CEA Recording Techniques & Equipment 3