CMP Mixing and Mastering 3 — Questions and Answers
Question 1: What is the role of dithering when bouncing a 24-bit mix down to a 16-bit master file?
- It increases the loudness of the final file
- It adds low-level noise to mask quantization distortion during bit-depth reduction (Correct answer)
- It removes noise from the recording
- It converts the sample rate of the file
Correct answer: It adds low-level noise to mask quantization distortion during bit-depth reduction
Dithering adds shaped noise that randomizes quantization errors, making the distortion from bit-depth reduction much less audible.
Question 2: Which compressor characteristic describes how quickly it releases gain reduction after the signal falls below the threshold?
- Attack
- Knee
- Release (Correct answer)
- Ratio
Correct answer: Release
Release time controls how fast the compressor lets the gain return to unity after the signal drops below the threshold.
Question 3: What does a 'null test' verify in audio production?
- That two audio signals are identical by confirming they cancel completely when summed out of phase (Correct answer)
- That a microphone has no frequency coloration
- That a mix has no clipping
- That a plugin introduces no latency
Correct answer: That two audio signals are identical by confirming they cancel completely when summed out of phase
When two supposedly identical signals are phase-inverted and summed, complete silence (null) confirms they are bit-for-bit identical.
Question 4: In parallel compression, what signal is typically blended back with the heavily compressed signal?
- A reverb-only version of the track
- The original uncompressed dry signal (Correct answer)
- A high-passed version of the signal
- A side-chained version from the kick drum
Correct answer: The original uncompressed dry signal
Parallel compression blends the squashed compressed signal with the unaffected dry signal to retain transients while adding density.
Question 5: What is the Haas effect, and how is it sometimes exploited in mixing?
- A psychoacoustic effect where a delayed copy (1-40ms) fuses with the original and creates perceived width without an audible echo (Correct answer)
- The tendency for bass frequencies to mask high frequencies
- A harmonic distortion phenomenon in analog tape
- The perceived loudness increase from stereo vs. mono
Correct answer: A psychoacoustic effect where a delayed copy (1-40ms) fuses with the original and creates perceived width without an audible echo
The Haas effect causes the brain to fuse a delay under ~40ms with the direct sound, which producers exploit to widen elements in a mix.
Question 6: What does 'pre-delay' on a reverb unit control?
- The time between the dry signal and the onset of reverb reflections (Correct answer)
- The decay time of the reverb tail
- The low-frequency cutoff of the reverb
- The mix ratio between wet and dry signal
Correct answer: The time between the dry signal and the onset of reverb reflections
Pre-delay pushes the reverb onset back slightly, allowing the dry source to be heard clearly before the reverb blooms.
Question 7: Which of the following best describes the concept of 'spectral balance' in mastering?
- Ensuring all tracks have equal volume levels
- The even distribution of frequency energy across the audible spectrum relative to genre references (Correct answer)
- Making the stereo field perfectly symmetrical
- Applying equal amounts of compression to bass and treble
Correct answer: The even distribution of frequency energy across the audible spectrum relative to genre references
Spectral balance refers to how well the low, mid, and high frequency energy is proportioned, typically compared against professional references in the same genre.
CMP Mixing and Mastering 3
What is the role of dithering when bouncing a 24-bit mix down to a 16-bit master file?