Mastering

Question 1

What is mastering?

Answer 1

Mastering is the final stage of audio production that happens after mixing — it prepares the finished mix for release by optimising tone, loudness, and consistency across formats.

Question 2

How does mastering differ from mixing?

Answer 2

-Mixing balances and processes individual tracks.
-Mastering processes the stereo mixdown as a whole — you can’t change instrument levels or effects parameters.

Question 3

What is the purpose of controlling dynamic range in mastering?

Answer 3

To use compression, limiting, or multiband compression to:
-Control dynamics,
-Increase average loudness,
-Prevent clipping or distortion.

Question 4

What does frequency response EQ achieve in mastering?

Answer 4

Subtle broad EQ adjustments to:
-Boost lows (power)
-Enhance highs (clarity)
-Use linear phase EQ to avoid phase smearing

Question 5

What is the purpose of an HPF and LPF in mastering?

Answer 5

-HPF (< 35 Hz): Removes rumble and prevents compression pumping, allowing louder masters.
-LPF: Removes hiss, especially during remastering.

Question 6

What are notch filters used for?

Answer 6

To remove resonances, hum, or other narrow-band noise from the stereo mix.

Question 7

How is stereo width controlled in mastering?

Answer 7

-Low frequencies = narrow (mono) for stability
-High frequencies = spread wide for spaciousness
-MS (Mid–Side) processing can treat the centre and sides differently
-Tools like Ozone imagers enhance stereo width
-Historical note: 1960s mixes are sometimes reissued in mono to reduce extreme L/R separation.

Question 8

What does “top and tail” mean in mastering?

Answer 8

Trimming and polishing the start and end of the master:
-Track starts within 1 second
-Natural fade or reverb tail at the end

Question 9

Why is an acoustically treated room important for mastering?

Answer 9

To ensure accurate monitoring so the mix translates consistently across playback systems.

Question 10

Why might a mastering engineer add a touch of reverb?

Answer 10

To “glue” the mix together, giving a sense of shared space between elements.

Question 11

What is MS (Mid–Side) processing used for in mastering?

Answer 11

To process mid (centre) and side (stereo width) components differently — e.g. tightening bass in the centre and widening the highs.

Question 12

What is a radio edit?

Answer 12

A shorter version of a track for radio play, often removing long solos or intros.

Question 13

What does noise reduction do in mastering?

Answer 13

Reduces unwanted hiss, hum, clicks, or dropouts — common in tape or older recordings.

Question 14

What mastering software tools exist?

Answer 14

-iZotope Ozone (professional suite)
-SoundCloud / LANDR (AI-based online mastering)

Question 15

Why are reference tracks used in mastering?

Answer 15

To compare tonal balance and loudness and ensure consistency across an album.

Question 16

What is dithering and why is it used?

Answer 16

Adds very low-level noise to randomise quantisation distortion when reducing bit depth (e.g. from 24-bit to 16-bit).

Question 17

What does an exciter do?

Answer 17

Adds high-frequency harmonics to restore brightness — originally used to replace top-end lost through analogue tape.

Question 18

What is remastering?

Answer 18

Revisiting and improving older masters — updating them to modern loudness and tonal standards or cleaning up the sound.

Question 19

What file format should a master be bounced in?

Answer 19

A high-quality uncompressed file (e.g. WAV, AIFF).

Question 20

1960s mastering characteristics

Answer 20

-Done on analogue tape → vinyl
-Used HPF / LPF to manage hum & hiss
-Mostly mono masters
-RIAA curve applied during vinyl mastering

Question 21

1970s mastering characteristics

Answer 21

-Warm analogue sound, fewer highs
-Use of noise reduction (Dolby / dbx)
-Masters transferred to cassette or vinyl

Question 22

1980s mastering characteristics

Answer 22

-More upper-mid and high frequencies
-Often bass-light by today’s standards
-Digital reverb and SSL bus compression appear
-Transition from analogue to digital mastering

Question 23

1990s mastering characteristics

Answer 23

-Rise of DAT / ADAT → full digital chain
-Start of Loudness Wars: 0 dBFS viewed as a target, not a limit
-Introduction of CD mastering

Question 24

2000s mastering characteristics

Answer 24

-Emphasis on deep lows and bright highs
-Loudness wars intensified until ~2010
-Post-2010: LUFS-based streaming loudness penalties reduced excessive compression
-Emergence of Dolby Atmos and AI-assisted mastering

Question 25

Vinyl mastering challenges

Answer 25

-Low frequencies reduced to prevent stylus jumping -RIAA curve EQ applied during cutting and reversed on playback -Sibilance and low-end imaging can cause distortion -Compression required for slower record speeds -Louder masters = larger grooves, reducing playtime -Inner grooves = poorer sound quality → track order matters

Question 26

Tape mastering characteristics

Answer 26

-Tape bias (high-frequency signal) ensures magnetic consistency -Saturation adds warmth but can distort at high levels -Noise reduction (Dolby, dbx) used to cut hiss

Question 27

CD mastering characteristics

Answer 27

-Digital medium → low noise, accurate response -44.1 kHz / 16-bit LPCM, up to 80 minutes of stereo -Wide dynamic range, high signal-to-noise ratio -Track sequencing, metadata, and gaps set during mastering -In 1990s, 0 dBFS seen as “goal” → Loudness Wars

Question 28

Mastering for digital audio and streaming

Answer 28

-File format (uncompressed / lossy / lossless) affects process -Services use loudness normalisation (LUFS-based) -Ensures consistent playback volume without listener volume changes

Question 29

What is loudness normalisation?

Answer 29

A process used by streaming platforms to analyse and adjust average loudness — quieter masters are boosted, overly loud ones turned down.

Question 30

Why has loudness normalisation reduced loudness wars?

Answer 30

Because overly compressed tracks don’t sound louder after normalisation, encouraging more dynamic masters again.

Question 31

What’s the difference between limiting and compression?

Answer 31

Limiting is an extreme form of compression with a very high ratio, ensuring signal peaks don’t exceed a defined threshold (e.g. 0 dBFS).

Question 32

What is multiband compression and why use it in mastering?

Answer 32

It splits the signal into frequency bands, allowing precise control of dynamics in each range (bass, mids, highs).

Question 33

Why are linear phase EQs used in mastering?

Answer 33

They preserve phase relationships across frequencies, ensuring no smearing or distortion of transients.

Question 34

What is meant by “translation” in mastering?

Answer 34

How well a mix or master sounds across different playback systems — checked on multiple speakers and headphones.