AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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| Week 8 - Mastering Questions |
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1. What is Mastering?
2. Why is mastering necessary?
3. What is Post Production?
4. Comment on “preparing your tapes”.
5. Comment on “stereo bass”.
6. Why is mono compatibility such an issue?
7. What is meant by the term “start ID”?
8. What are the three types of Disc Cutting?
9. What information should be written on your master tapes?
10. What is meant by multi-band compression?
11. Explain the term dynamic range.
12. What is the formula for dynamic range?
13. What is meant by SNR?
14. Describe gain riding.
15. Comment on this article:
http://www.digido.com/index/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=93/
Pay particular attention to what you feel about the subject. Essentially it is about where YOU stand on the subject within the big picture. For example are you joining the race or are you sitting on the fence? What would you do given the reins to a potential top ten album?
16. What is meant by normalling?
17. Explain DC offset
18. How can the target audience affect mastering decisions?
19. What happens to the audio signal when a aural enhancer is applied?
20. What does relative loudness mean?
21. What does r.m.s. mean?
22. What is meant by 'entertainment quality'?
23. What happens if you leave excessive, short transients in the music?
24. What is The K-System?
25. What are The Equal Loudness Contours?
26. What is MetaData?
27. Explain the term Headroom.
28. Explain the term Crest factor.
29. What skills and abilities must a Mastering Engineer possess?
30. What does the term “Masking” mean?
31. Explain the Hass Effect.
_________________
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Mon Apr 26, 2004 8:26 pm |
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hoggs33
Joined: 09 Feb 2004
Posts: 55
Location: Nottingham, England |
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1. What is Mastering?
Mastering is the process that comes after mixing and turns the mix into the sound that will be heard on the finished product (CD etc). Mastering is the final process and no alterations will be made after the mastering process.
2. Why is mastering necessary?
Mastering is necessary to compensate, as far as possible, for the deficiencies of the medium that ill be used, to optimize the sound quality and level and to match different tracks in terms of EQ and level so that they fit together well on an album, particularly from one track to the next.
3. What is Post Production?
This would be the preliminary steps taken prior to the actual mastering being carried out and would include things such as preparation of tapes etc. You should also ensure that the tapes contain the best mix.
4. Comment on “preparing your tapes”.
This is getting the right labels on the right tapes such as labelling a tape for mastering as submaster, work tape or final mix etc. This avoids confusion when searching for the real master. They should also be labelled with the following information – Album Title, Artist, Contact details, date and tape number (e.g Mix Tape 1 of 2). The disc format and technical info should also be labelled such as sample rate, file format etc.
5. Comment on “stereo bass”.
This has relevance in respect of cutting a track to vinyl. It is important to ensure that the bass is not too prominent in a mix as it will require the stylus to move up and down and this may imply too much movement for the stylus to make. To stop this the bass can be placed centrally in the mix so that it does not dictate the grooves imprinted onto vinyl.
6. Why is mono compatibility such an issue?
Not all final products will be played on a stereo system and a radio station could broadcast in mono or the radio being listened to could be mono. If a mix is not compatible with mono players or stations then this could result in a different sound on playback
7. What is meant by the term “start ID”?
It is the marker that represents the start of the track
8. What are the three types of Disc Cutting?
Laquer – a laquer disc is cut and is used to produce the final metal disc that stamps the vinyl
Acetate – A similar process to laquer, however the disc is the same size as the record and can be played and checked for quality prior to committing to a metal master which will stamp the vinyl.
Direct Cut – This is a metal disc that is cut directly on a cutting lathe.
9. What information should be written on your master tapes?
Artist/Band name, track names and times, studio, producer, record company, contact details.
10. What is meant by multi-band compression?
Multi-band compression allows multiple frequency bands to be selected from a final master, which can then be compressed individually. It enables the dynamics to be fine tuned even after mixdown and is used mainly during the mastering stage.
11. Explain the term dynamic range.
The difference between the quietest and loudest sounds in a recording or piece of music.
12. What is the formula for dynamic range?
Maximum dB level – minimum dB level
13. What is meant by SNR?
Signal to noise ration and is the difference in dB between a ‘reference’ signal and the noise floor
14. Describe gain riding.
The process of manually adjusting fader levels to compensate for parts of the recording that are well above or below the average dynamic range of the recording.
15. Comment on this article:
http://www.digido.com/index/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=93/
Pay particular attention to what you feel about the subject. Essentially it is about where YOU stand on the subject within the big picture. For example are you joining the race or are you sitting on the fence? What would you do given the reins to a potential top ten album?
I personally think the loudness thing due to record company pressure for their tracks to have the most impact on a listener particularly on the radio in order to sell enough units as possible. My view is that the major record companies are not bothered about the quality or longevity of the music as long as it makes them as much money as possible as fast as possible. There are very few artists today who I would expect to still be around in 10 or 20 years time having created classic albums that are still selling in years to come – commercial music has become ‘throw away’ pop not designed to last.
I think ‘loud’ records in a particular genre (rock etc) do work well – it is what the music needs – an in your face mix that doesn’t relent. However different genres of music should have different treatments, particularly music designed to have a wide dynamic range. I suppose I am a bit ‘on the fence’ with this issue as I feel it is appropriate in certain circumstances and not others. If I was faced with mastering a top 10 album I would endeavour to give it the best possible treatment relative to the style of music. However I envisage that if it was being financed by a major label then pressure from the label to produce what they want would win over the artistic side of things – they are paying the bill after all! Just because one recording is quieter than another does not make it a bad production but the industry has changed dramatically over the last 10 or 15 years where companies want to make a fast buck and move onto the next project rather than produce classic recordings that may not be an instant hit but gradually work their ay into most peoples record collections over many years which is quite sad really.
Not sure if I have gone off on a bit of a tangent on this question but that is my overall opinion.
16. What is meant by normalling?
Raising the volume of a track to its highest point without clipping – this is done by scanning the waveform of a track for it loudest point and then raising the volume of the rest of the track in proportion.
17. Explain DC offset
This is a artefact that may appear in a digital track such as pops and clicks when and A/D converter is not well calibrated. This can be corrected during the mastering process.
18. How can the target audience affect mastering decisions?
The type of mastering can depend on the type of music and target audience – for example a heavy metal or thrash metal track will want to be a loud as possible probably with little dynamic range whereas a classical recording would be treated very differently having a much greater dynamic range.
19. What happens to the audio signal when a aural enhancer is applied?
It adds brightness and detail to a track without affecting the volume. This is done by high frequencies passing trhough a high pass filter which are enhanced by the addition of artificial harmonic related components giving a richer, brighter sound.
20. What does relative loudness mean?
21. What does r.m.s. mean?
Root mean Squared and is the average audio signal voltage or AC voltage that an amplifier will emit. It is calculated by adding together the squares of the individual values under consideration, dividing it by the number of values and then taking the square root of it.
22. What is meant by 'entertainment quality'?
Good enough for broadcasting, TV and internet etc but not good enough wuality for Hi-Fi
23. What happens if you leave excessive, short transients in the music?
This could result in the music having an excessive dynamic range making it harder to hear the quieter parts of the music.
24. What is The K-System?
This is a metering and monitoring standard used as a meter to monitor relative loudness. There are 3 scales which sets the K system meter so that it is suitable for different genres of sound
K20 is for a wide dynamic range such as theatrical or classical productions and pop music with a big budget.
K14 is used to monitor medium compressed hi-fi productions such as generic rock, pop and folk music.
K12 is used for productions to be broadcast.
25. What are The Equal Loudness Contours?
They provide a graphical representation of the frequencies to which the human ear is most sensitive and can also be known as Fletcher-Munson curves. If playback levels are too high or too low for optimal reception they can be changed as they will show up in the graphic as an unbalanced frequency image.
26. What is MetaData?
This is data about data and will include data about the content of the data and its condition, who produced it , where and when it was produced and what means were used to do so.
27. Explain the term Headroom.
I found various explanations – not sure which is the most relevant (if any!!) – they are as follows:-
- The level difference in dB between normal operating level and clipping level in an amplifier or audio device.
- A similar level difference between normal tape operating level and the level where distortion would be 3%
- The difference in dB, between the peak and RMS levels in program material.
28. Explain the term Crest factor.
The Crest Factor of a test signal is the ratio in dB between the volume of the average level and the average peaks. If the Crest Factor is known for a test signal, e.g 6dB for the IEC rating, then the peak handling can be calculated by doubling the noise rating for every 3dB of Crest Factor? What the hell does that all mean!!!!!!
29. What skills and abilities must a Mastering Engineer possess?
A good ear for what sounds clear etc and good knowledge of frequencies etc. Good technical knowledge of all the stuff mentioned in these questions. A good understanding of different musical genres and their target audience.
30. What does the term “Masking” mean?
The characteristic of hearing by which loud sounds prevent the ear from hearing softer sounds of similar frequency.
31. Explain the Hass Effect.
In simple terms this is a factor in human hearing where delay has a much bigger effect on human perception of direction than level does |
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Thu Apr 29, 2004 8:36 pm |
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griff505
Joined: 23 Feb 2004
Posts: 68
Location: Bristol |
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1. What is Mastering?
Mastering is the altering of a track for reproduction, i.e. to ensure it sounds good on a wide range of different playback systems. Mastering increasingly aims to make a track as loud as possible whilst still preserving its clarity, as most people perceive sounds that are louder, as sounding better. The main components of mastering are tonal balancing, and level adjustment. Tonal balancing is usually accomplished with equalisation, and level adjustment is primarily achieved with compression. There are also other effects that are used, like enhancers, exciters, and stereo expansion. The mastered track is the ‘blueprint’ for other copies made of the track.
2. Why is mastering necessary?
Mastering is required to allow the mix to play well and sound good on a wide range of audio playback equipment, from a club PA to a car CD player. Mastering can solve problems from the mixing stage, such as balancing certain frequencies. The Mastering Engineer will also consider the target audience and tailor the mastering process to suit the genre that the sound is in. If a number of tracks are being mastered for the same project then the Mastering Engineer will ensure that the volume level and tonal balance is appropriate for inclusion on the same CD or album.
3. What is Post Production?
Post-Production takes place after the recording of a track. It includes editing, mixing, and addition of effects such as compression and eq. Post-production is carried out on an already mixed track; therefore different techniques have to be used compared to those used at the mixing stage. Effects applied at this stage affect the whole mixed track, not just individual tracks. At the post-production stage certain frequencies can be increased or reduces, and its main purpose is to make a collection of tracks or recordings sound crisp and consistent for release.
4. Comment on “preparing your tapes”.
Tapes are prepared to ensure all information necessary for the mastering stage is available to the mastering engineer. Tapes should be labelled with track names, dates and times, tape speed, track format, noise reduction, effects used, sample rates, and the equipment the tracks were made on.
5. Comment on “stereo bass”.
Stereo bass needs to be considered when a track is going to be cut to vinyl. When a piece if vinyl is being cut, left and right movement is for mono signals, and up and down for stereo signals. To cut a deep bass note a lot of movement is required which can result in a lot of movement which can result in the groove being too deep or too shallow. This is made worse if the bass signal is panned to the left or right in the stereo spectrum. Cutting rooms have devices to correct this – Elliptical Equalised, Vertical Bass Cut and Vertical Acceleration Limiter, however it is best to place bass in the middle of the mix to avoid such problems.
Basses have the largest amplitudes on disc - therefore deep stereo bass is not possible at all!
6. Why is mono compatibility such an issue?
A lot of radio stations still broadcast in mono therefore this needs to be considered during the mixing and mastering stage. A mix may sound good in stereo but not so good in mono. Phase cancellation is another problem that needs to be considered with mono playback.
7. What is meant by the term “start ID”?
The start ID is a marker at the start of tracks on a master tape. Each track will have a start ID and end ID.
8. What are the three types of Disc Cutting?
Lacquer Master
An aluminium disc which has been given a lacquer coating. The diameter of the Lacquer disc is always larger than the finished record. For example a 12" single or album would be on a 14" Lacquer. This is the master disc; it should not be played or touched. It is very fragile and the grooves can be easily damaged. The metalwork is made by a process called electroplating. Space is needed to clip on the electrode. If the master disc were the correct size, the clip would damage the grooves. Lacquers must not be placed near a heat source, in a hot room, or where the sun shining through the window will heat them. If Lacquers need to be stored for a long time, they should be kept in the fridge no cooler than 5 degrees Centigrade.
An Acetate
An Acetate is basically the same as a Lacquer, but the correct size. This is important for 12" records, as few record players can have a 14" disc fitted on them. The main purpose of an acetate is to play it at home to make sure the cut is correct, before you pay for the metalwork to be made. The record factory will send one or two test pressings before they press the rest of your records. The Acetate and the test pressing can be used to compare the quality of the finished project. If they do not sound pretty much the same then there may be a problem. Every time you play an Acetate you damage it - heavy stylus weights, back cueing and scratching will all ruin the Acetate very quickly. Test Pressings can use them to prove that the main run is not as good as the Test Pressing which you approved. Recordable CD's (CDR) are almost exclusively used for this job now.
Direct To Metal
Direct to Metal Masters use a copper blank instead of Lacquer, the disc comes in one 14" size. DMM has several advantages:
- DMM allows some of the stages of the metal work process to be bypassed. This results in the noise of the record (without music) being less; each stage of metalwork adds a little more noise.
- DMM it will handle the top end better and is more forgiving with sibilance.
Disadvantages:
- DMM cut gets noisier the deeper the stylus digs into the copper, therefore the depth of the groove is kept to a minimum. If there is a lot of low bass, it is possible to encounter a problem where a small percentage of finished records jump.
9. What information should be written on your master tapes?
Title, Artist, Contact Details, Date, Tape Number, Tape Speed, Type of Tape, Disk Format, Sample Rate, Wordlength, File Format, Effects Used, Special Requirements (12”, 7”, Stereo, Mono).
10. What is meant by multi-band compression?
A multi-band compressor comprises of a set of filters that split the audio signal into the required number of frequency bands (three is a common format). After passing through the filters, each frequency band is fed to its own compressor, after which the signals are recombined. Multi-band compressors allow the audio to be compressed without a loud event in one frequency band resulting in gain reduction is other bands. Therefore if a track features a very loud kick drum, instead of pulling the whole mix down on each kick drum beat, only the low-frequency sounds will be compressed, leaving the mid and high frequencies unaffected.
11. Explain the term dynamic range.
The range in dB between the highest signal that can be handled by a piece of equipment (0dB / DFS) and the level at which small signals disappear into the noise floor. The noise floor is the noise present in a system without any signal present. A system with a high dynamic range will be quieter than one with a lower dynamic range.
Digital systems have no headroom the entire dynamic range of the signal must fit within the limits of the dynamic range of your recorder. The only meaningful absolute on a digital recorder is the point at which you will go into overload. 0 dB represents digital ceiling, or full-scale. The negative numbers on the scale represents your current level relative to the ceiling.
12. What is the formula for dynamic range?
Dynamic range is the number of decibels between the peak level and the noise floor, indicating the ‘maximum-to-minimum’ range of signal levels which may be handled by the system.
Peak level (dB) - noise floor (dB) = dynamic range (dB)
13. What is meant by SNR?
Signal-to-Noise-Ratio - The number of decibels between the reference level and the noise floor of the system. The "signal" reference level must be stated. This is the expected nominal operating level, +4 dBu for professional audio, or the maximum output level, usually around +20 dBu.
14. Describe gain riding.
Gain riding is the constant monitoring and adjusting of incoming gain levels to prevent the overloading of the tape or hard disk. The disadvantage of this technique is the delay between the gain increase and the sound engineer adjusting the incoming signal. This time delay can be overcome through the use of a compressor.
15. Comment on this article:
http://www.digido.com/index/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=93/
Pay particular attention to what you feel about the subject. Essentially it is about where YOU stand on the subject within the big picture. For example are you joining the race or are you sitting on the fence? What would you do given the reins to a potential top ten album?
After reading this article my first thoughts concerned just what it is about records that sell (i.e. top 20 releases) and them sounding loud. I’m still not sure. Does it have anything to do with the cheap systems that popular releases are played back on?
I believe that loud does not equal best, and prefer music with much larger dynamic range, such as Mogwai (who have been know to be so quiet in sections that the BBC’s emergency tape has kicked in mid-song on the John Peel show) and Godspeed You Black Emperor. I also enjoy music by minimalist composers such as Bernhard Günter, whose music is so quiet that sometimes you do not realise it is even playing!!! A far cry from the loudness onslaught of an album by Britney or Beyonce. However I accept that certain types of music, such as club-orientated dance music does need to have a small dynamic range in order to keep the crowd moving all the time.
16. What is meant by normalling?
Normalisation – Normalisation is setting all the tracks to the same level. The process of normalisation increases the volume of the signal by a specified amount to bring the highest peak up to 0 dB. Normalising can take place during a CD transfer and is a simple an easy way to get the audio as loud as it can be without distorting the signal or changing the dynamics whatsoever.
17. Explain DC offset
DC - Direct Current - A signal whose midpoint is skewed away from zero is said to have a DC offset. It is merely a constant voltage that is present and which can eat up headroom and cause clicks and pops during editing. The DC Offset process can be used to negate a pre-existing offset. DC offset is often caused by A/D converters.
18. How can the target audience affect mastering decisions?
Each style or genre of music has certain recording characteristics or standards. These characteristics must be understood before the mastering process is approached if the aim is to sell the tracks or album conforming to the existing accepted characteristics. Two extreme examples are classical music, where the listener wants to hear the volume changes that would naturally occur from instrument to instrument, and dance music which needs to keep a constant level in order to keep the dance floor moving.
19. What happens to the audio signal when an aural enhancer is applied?
An enhancer or exciter adds a harmonic distortion to the audio it is applied to with the aim of making it sound more pleasing to the listener. Theories of psychoacoustics demonstrate that even-harmonics make sounds soft, warm and full, whereas odd-harmonics tend to make things metallic, hollow and bright. Lower-order harmonics control basic timbre, while higher-order harmonics control the "edge" or "bite" of the sound. Harmonic distortion changes the original sound dramatically, more so than measured performance might predict.
20. What does relative loudness mean?
Relative loudness – The perceived level of a sound will vary from person to person, therefore the dB system is used to measure relative loudness. If sound is said to 15 dB, it is 15 dB no matter what. Even if one person describes the sound as moderately loud and another describes it as very loud, there sound can be said to be 15 dB with certainty.
21. What does R.M.S. mean?
Root Mean Square – The square root of the average square of the instantaneous values of an AC output. For a sine wave the RMS value is 0.707 times the peak value.
22. What is meant by 'entertainment quality'?
Entertainment quality is the amount of enjoyment that comes from a piece of work regardless of its technical or musical qualities. For example all the music found on MTV that uses the same formula to produce tunes that, although technically well produced, will be forgotten within months.
23. What happens if you leave excessive, short transients in the music?
If a vinyl master is being made, excessive short transients could cause a pre-echo effect to the track. This is due to the chemical composition of lacquer, which attempts to achieve an equilibrium when grooves are tightly spaced, resulting in an imitation of the music yet to come.
24. What is The K-System?
K-System is a metering and monitoring standard that integrates the best concepts of the past with current psychoacoustic knowledge in order to avoid the chaos of the last 20 years. Instead of having 0 dB at the top of the meter, the K-System uses a metering system where 0 dB is a reference loudness, which also determines the monitor gain. There are three different K-System meter scales, with 0 dB at 20, 14, or 12 dB below full scale, for typical headroom and SNR requirements. The three K-System meter scales are named K-20, K-14, and K-12.
Several accepted methods of measuring loudness exist, of varying accuracy (ISO 532, LEQ, Fletcher-Harvey-Munson, Zwicker and others). The extendable K-system accepts all these and future methods, plus providing a "flat" version with RMS characteristic. Users can calibrate their system's electrical levels with pink noise, without requiring an external meter. RMS also makes a reasonably-effective program meter that many users will prefer to a VU meter. The K-20 meter is intended for wide dynamic range material (theatre mixes, audiophile music, classical music, etc). The K-14 meter is for the vast majority of moderately-compressed high-fidelity productions intended for home listening (home theatre, pop, folk, and rock music). And the K-12 meter is for productions to be dedicated for broadcast.
If console and workstation designers standardize on the K-System it will make it easier for engineers to move programs from studio to studio. Sound quality will improve by uniting the steps of pre-production (recording and mixing), post-production (mastering) and metadata (authoring) with a common "level" language. By anchoring operations to a consistent monitor reference, operators will produce more consistent output, and everyone will recognize what the meter means. The K-System can become the lingua franca of interchange within the industry, avoiding the current problem where different mix engineers work on parts of an album to different standards of loudness and compression.
25. What are The Equal Loudness Contours?
Equal Loudness Contours are curves represented in graph form as a function of sound level and frequency which listeners perceive as being equally loud. Sometimes known as the Fletcher and Munson Curves, the Equal Loudness Contours demonstrate that the ear does not hear all frequencies with equal sensitivity. The ear is most sensitive to frequencies around 2000 Hertz and less sensitive to frequencies which are higher or lower. This phenomenon has significance for determining optimum levels for monitoring music in studio environments. If the playback level is too high or too low an unbalanced frequency image is likely to occur particularly in the low frequency range where our perception of loudness changes significantly at various loudness levels. A suggested optimum monitoring level is 85 db.
26. What is Metadata?
Metadata is a component of data which describes the data. It is "data about data." Metadata describes the content, quality, condition, and other characteristics of data.
27. Explain the term Headroom.
Headroom, expressed in dB, is the difference between the highest level present in a signal and the maximum level an audio device can handle without noticeable distortion. For example, a mixer operating with a nominal line level of +4dBu and a maximum output level of +22dBu has 18dB of headroom.
When recording to tape there is room for to record above 0 dB, which can produce a pleasant compressed distortion effect. However with digital there is not margin for going above 0 dB, if 0 is exceeded an ugly digital distortion sound results
28. Explain the term Crest factor.
Crest Factor is the ratio between the peak and RMS values. If a unit is said to have a crest factor of 2:1 it can take a peak of two times the RMS value of the supply without clipping.
29. What skills and abilities must a Mastering Engineer possess?
A Mastering Engineer must have an excellent set of ears to pick out frequencies that need adjustment. Also an engineer must have an understanding and appreciation of many genres of music and the audience of the particular genres requirements. These need to be balanced with the wishes of the artist who produced the track. They must also know the technical specifications of the format to which the master will be released to the public (CD, Vinyl, DVD) and master the track in accordance to the format.
30. What does the term “Masking” mean?
When two sounds that contain similar frequencies are played simultaneously, the weaker sound often has the overlapping frequencies 'masked' by the frequencies from the stronger sound. The frequencies of the weaker sound are still there; they are just not discernable over the more dominant sound with the same frequencies. Frequency also plays a part; a louder sound heard at one frequency prevents softer sounds near that frequency from being heard, with mid-band frequencies mask far better than low frequencies).
31. Explain the Hass Effect.
The Hass Effect is a psychoacoustic effect by which the time of arrival of a sound to the left and right ears affects our perception of direction. If a signal is presented to both ears at the same time at the same volume, it appears to be directly in front of us. But if the signal to one ear, still at the same volume, is delayed very slightly - 0 to 5 ms - the sound appears to be coming from the earlier (non-delayed) side. |
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Fri Apr 30, 2004 12:03 am |
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iNSTiNCT2765
Joined: 05 Nov 2003
Posts: 60
Location: Denmark |
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Week 8 - Mastering
1. What is Mastering?
Mastering is the final touch you add to a final mix. All the mixes you need mastered are put into an editor and then sequenced. Then by using mastering techniques, tracks are made louder, sweetened, more pleasant to listen to and just plain more professional sounding. This is achieved by using multi-band compressors, EQ’s, Spacial Enhancers, Limiters and other mastering gear. It is the last process in making a record before the CD is sent to the duplication plant.
2. Why is mastering necessary?
Mastering is necessary to give an album a more similar ‘overall sound’ from track to track. For an album, mastering makes all tracks evenly loud so you don’t have to touch the volume dial while you listen through it. Recordings also need to be enhanced making them more compatible over many different kinds of listening systems.
3. What is Post Production?
Post Production is everything done with final mixes after they have been down mixed to a stereo track.
4. Comment on “preparing your tapes”.
The tapes brought to the mastering engineer should be the first generation copies for optimal sound quality. They should be labelled with the album title, song titles and start time for each song.
5. Comment on “stereo bass”.
Stereo bass can cause problems during the vinyl cutting stage due to the large amplitude of low frequencies. 
6. Why is mono compatibility such an issue?
Mono compatibility is important because when the song is played on a radio station it may be broadcast in mono or the radio you are listening to might only be mono. If the track isn’t mono compatible, it may sound different in mono and some important details in the song may be phased out and not heard, making the song sound dull.
7. What is meant by the term “start ID”?
This is a marker that represents the start of a track. This way, it is easy to locate a track on a DAT tape.
8. What are the three types of Disc Cutting?
Lacquer
Acetate
Direct to Metal
9. What information should be written on your master tapes?
The artists’ names
The album title
The track names
The start time for each track and duration
The date it’s handed over for mastering
Contact information.
10. What is meant by multi-band compression?
Multi-band compression offers independent compression to different frequency ranges on the same audio file. This can change the dynamics and sound of an already mixed down song by bringing out certain elements or making them sit further back in the mix.
11. Explain the term dynamic range.
Dynamic range is the range from the highest signal level to the lowest audible level (noise floor) in a recording.
12. What is the formula for dynamic range?
Maximum dB level – Noise floor = Dynamic range in dB
13. What is meant by SNR?
SNR (signal to noise ratio) is the ratio between the noise floor and the signal. The more signal you have, the less noise will be heard so it is always good to get the highest possible signal level, less of distortion when recording.
14. Describe gain riding.
Gain riding is manually moving faders up and down to account for signals coming in too loud or too low. This is what a compressor does automatically.
15. Comment on this article:
http://www.digido.com/index/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=93/
Pay particular attention to what you feel about the subject. Essentially it is about where YOU stand on the subject within the big picture. For example are you joining the race or are you sitting on the fence? What would you do given the reins to a potential top ten album?
The big debate is obviously if louder is better. I personally like loud records because it means that I can get them to play louder in my car. This is my personal view until I get a new stereo system installed in my car with a subwoofer and amp. Then it won’t really matter to me. When I’m listening on headphones, it doesn’t really matter how hot the mastering has made the record as long as the tracks sound good and are at an equal level throughout the CD. Here it’s actually preferred to have an album with more dynamic range because it enhances the listening pleasure. It would make sense that if making a CD too hot degrades the sound, it shouldn’t be done but that’s not reality. Record companies are competing with each other to get the loudest product out on the market, which in their minds equals a better product (louder is better). It all depends on the market and target audience really. Where is the CD going to be played most? One thing I don’t understand is why Dr. Dre’s Chronic 2001 wasn’t on the list. The CD is HOT but very open and the sound quality is amazing. The tracks are not mastered bass heavy because it is a CD intended for listening in cars with subwoofers and bass heavy systems. If it was up to me, then the Top Ten album I have control over would be mastered to compete with other recordings in the genre but it wouldn’t be so hot that the quality of the sound suffers; just so you wouldn’t have to touch the volume knob if it was the next CD in the changer.
16. What is meant by normalling?
Normalling (Normalizing?) is a term for raising the overall volume of a track to its highest without it clipping. This is done by taking the highest peak in the track and raising it to its loudest and everything else follows in proportion. This is done to ensure that all the dynamic range available is being used.
17. Explain DC offset
When hardware such as a soundcard adds DC current to a recorded audio signal, it results in audio not being centered on the zero crossing or baseline. This can result in glitches when adding sound effects to the audio file. This is DC offset. A sound editor such as Sound Forge can compensate for DC offset by adding a constant value to the samples in the sound file.
18. How can the target audience affect mastering decisions?
When mastering a CD, the target audience, target listening systems and target listening locations should be taken into consideration. Different styles and genres of music have their own unique sound and shouldn’t be mastered the same way. Dance music, for instance, has the bulk of its target audience as the club goers and is played on loud sound systems. The dynamic range doesn’t factor in here and a lot of compression can be added to smash the drums to give a pounding rhythm. Classical music on the other hand is all about it’s wide dynamic range and it needs to be taken into account when mastering the pieces.
19. What happens to the audio signal when an aural enhancer is applied?
Musically and dynamically related harmonics are added to the signal to give it a sound closer to its natural acoustics.
20. What does relative loudness mean?
Relative loudness is the perceived loudness of a track. Two tracks can be peaking at the same level but one is perceived to be louder than the other because it has a louder average level.
21. What does r.m.s. mean?
Root Mean Square of a sound is the measure of the intensity of the sound over a period of time. By raising this level and not the peaks, a track can be perceived as being louder even though the overall level hasn’t been changed.
22. What is meant by 'entertainment quality'?
This means the recording is on a high enough level of quality to be broadcast on radio and television.
23. What happens if you leave excessive, short transients in the music?
This gives a wide dynamic range. It makes the perceived loudness of the track lower than it could be if a limiter is applied to the track to stop the transients and bring the overall level up.
24. What is The K-System?
Grammy Award winning mastering engineer Bob Katz invented the K-System. It is a way of monitoring the RMS level of a track. A level of K-14 is the standard for pop music. It means there is a dynamic range of 14 dB from the RMS level, which is calibrated to –14 dBFS to the clipping level 0 dB in digital music. Classical music has a wider dynamic range and would have a setting of around K-20. Audio for broadcasting would have a setting of K-12.
25. What are The Equal Loudness Contours?
The Equal Loudness Contours are graphical illustrations of the threshold of hearing at different frequencies and the apparent levels of equal loudness at different frequencies. The ear is more sensitive to some frequencies than others and even if two frequencies are equally loud, one may be louder in level and as the volume is turned down, the ear becomes less sensitive to them.
26. What is MetaData?
MetaData is data that comes with data. It holds information about the data such and authoring data and can be used to control certain characteristics of the audio.
27. Explain the term Headroom.
Headroom is the difference between the loudest sample of audio and the maximum level the system can handle before audible distortion.
28. Explain the term Crest factor.
The Crest factor is the ratio of RMS to Peak Level current. 
29. What skills and abilities must a Mastering Engineer possess?
A Mastering Engineer should have a working knowledge of the different market places for different styles of music and how they should sound. They should have a good ear for details in a mix and know what the dominant factors are and need to be emphasized. They should be able to identify frequencies that need to be worked on to give the recording a better sound.
30. What does the term “Masking” mean?
Masking means when two instruments share the same frequency and as a result, one is not heard because it is being covered by the more dominant sound.
31. Explain the Haas Effect.
The Haas effect is also called the Precedence effect. If the delay of a sound reaches the ear within 01-40 ms after the direct sound, it is perceived to be part of it and not a separate sound. This can help determine the location of the sound. |
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Sat May 01, 2004 10:22 pm |
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albertom
Joined: 21 Jan 2004
Posts: 22
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1. What is Mastering?
Mastering is the technical and creative act of balancing, equalizing and enhancing, analog or digital tapes so that the finished product will have attained the maximum musicality and competitiveness in the open market.
2. Why is mastering necessary?
You can skip the mastering process. Chances are that your CD will not have the polish, nor the presence and sheen to stand up to the majors. When you've put hundreds of pre-production and studio hours and seemingly countless dollars into your project why settle for second rate? The personal satisfaction along with avoiding that "local CD sound" are worth the price of having your album professionally mastered. It will make your project stand with the best as well as give people a good first impression of your music.
3. What is Post Production?
Process of editing, sweetening, EQ matching, level matching, limiting, song sequencing and dozens other tools to create the finished album.
4. Comment on “preparing your tapes”.
Preparing the tapes for mastering includes adequate labeling and documentation (what is where, also what you are concerned about), putting leaders at the beginning and at the end of the tape, putting leaders between songs except for recordings of live performance. Analogue tapes should be equipped with test tones.
From the processing side, the tapes should contain the best mix (or, better yet, alternative mixes), any post-mix processing (compressing, EQ, noise reduction, normalizing etc) should be avoided since this is the mastering engineer's job.
All sources submitted for mastering must be properly prepared. Since the cutting level (volume) on the record is dependent on the length of the program, accurate timings are critical. The time for each track, and the total running time, including spaces between songs, must be provided for each side.
5. Comment on “stereo bass”.
Using too much stereo on basses can make the cutting stylus to loose contact with the desk and the groove will disappear. Also, low frequency waves are less directional than the higher ones and so the perceived stereo effect is not so great at basses anyway.
6. Why is mono compatibility such an issue?
By the late-80's few paid attention to music over AM, but there was MTV and Music videos which most people listened to through mono systems. This made mono compatibility still a viable subject. Even in the early 90's releases sounded good in mono and not as good in the stereo form. Now as the clocks roll-over with lots of zeros, it seems that a good sounding mono rendition is still something desirable.
Streaming audio allows the web-surfer to hear the audio quickly without waiting several minutes to "download" an audio file. There are severe limits to the size of the file that can be "streamed" by the average surfer. To make the files small enough to "stream" audio quality is often limited to "AM radio quality" (which is pretty bad by today's standards). Mono files are half the size of stereo files, so you can get "twice the quality" (on the high end) by posting mono rather than stereo files. So after all of these years, with great leaps of technology, mono is again important to the recordist.
7. What is meant by the term “start ID”?
Start Ids must be put on CD-Rs and DATs for each track or every point, which requires a visible spread on the record. Contrary to popular belief, visible spreads are made manually, and have nothing to do with the amount of space between tracks on the source. But, we must know exactly where you want them. An accurate track sheet, with the the name of each track, it’s time and track number ( A-1, A-2, B-1 B-2 etc.) and the running time for each side should be included with the source. Please type or print this information.
8. What are the three types of Disc Cutting?
Lacquer Master
Consists of an aluminium disc with a lacquer coating. It is bigger than the disk it goes on to form. It is the master disk and should not be played or touched as grooves are easily damaged. As it is a very sensitive process it should not be subjected to heat or sun lest the surface be damaged. This would have a detrimental effect on the recording itself. Once the grooves are set in lacquer it is then commonplace to put the media in the fridge.
Acetate
An acetate works on the same basis as Lacquer, but it is the same size as the eventual disc. This way you can take it home and play it to make sure you are happy with it before committing it to metal and then onto vinyl. As the acetate can be kept and used it is also useful for comparing to the
final product to make sure it has been pressed correctly. However, repeat playing are not advised as the acetate as it gets damaged with each play. It is designed for test purposes as opposed to playing purposes.
Direct to Metal
In this case a blanks copper disc is used to record directly onto. It is the same size as the Lacquer Master, but does not have the lacquer cover and much of the series of steps needed to manufacture the Lacquer Master are not necessary. The noise level of the media when played as blank is
preferable, and the treble end is handled better. As the grooves engraved onto the disk are more shallow than vinyl it may not handle bass-heavy recordings well.
9. What information should be written on your master tapes?
Song List, Duration of each Song, Split Point for Side A and B, Total Duration of each Side
10. What is meant by multi-band compression?
In essence, a multi-band compressor comprises a set of filters (similar to a PA system's active crossover) that splits the audio signal into two or more frequency bands. Three- or four-band compressors are perhaps the best compromise between versatility and ease of setting up. After passing through the filters, each frequency band is fed into its own compressor, after which the signals are recombined. The main advantage of multi-band compression is that a loud event in one frequency band won't trigger gain reduction in the other bands, so when that loud kick drum comes along, instead of pulling the whole mix down with it, only the low-frequency sounds (kick and bass instrument) will be compressed, leaving the mid-range and high frequencies untroubled. Similarly, a loud event in the mid-range won't affect the extreme high or low frequencies for the same reason.
11. Explain the term dynamic range.
The dynamic range of a signal processing system can be defined as the maximum dB level sustainable without overflow (or other distortion) minus the dB level of the ``noise floor''.
Dynamic range is the difference between the softest and loudest sounds we can hear. Or, to put it another way, the difference between the softest and loudest sounds in a recording. Dynamic range is measured in decibels (dB). The typical dynamic range for a cassette recording is around 60 dB, while today's digital recordings can reach a dynamic range of over 90 dB. Compare this to 100 dB or more for live performances.
12. What is the formula for dynamic range?
The formula is:
D = log (Io/I)
where Io is the intensity of the light falling on the slide (or negative) and I is the intensity of the light transmitted by the slide (or negative).
13. What is meant by SNR?
Signal-to-noise ratio. Is a measure of signal strength relative to background noise. The ratio is usually measured in decibels (dB).
14. Describe gain riding.
Gain riding means manually moving the faders so that the system could manage with the wide dynamic range of the music. When the signal in a track goes too high, you bring it down by lowering the fader. When it turns back to where it was, you raise the fader.
15. Comment on this article:
http://www.digido.com/index/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=93/
Pay particular attention to what you feel about the subject. Essentially it is about where YOU stand on the subject within the big picture. For example are you joining the race or are you sitting on the fence? What would you do given the reins to a potential top ten album?
As mentioned in the article, as the absolute loudness goes up, the sound quality can go down. If that the case I agree that certain step should be established to maintain the quality level in a product/CD to be released to the public. I think that a recording engineer (a good recording engineer) knows the best sound quality to be delivered to the public; otherwise the product won’t have a good reception, which may affect his image as Recording Engineer. We can educate the listeners offering them good quality.
16. What is meant by normalling?
Normalling is a wiring scheme whereby a signal path is established from one audio device to another without the use of a patch cord. This is known as the “normal path.” The normal path between a pair of jacks is most commonly wired internally from the source jack to the destination jack.
17. Explain DC offset
The DC voltage or current present on a signal.
Means that a given audio source does not have the correct 0-crossing, and is shifted either up or down from there.
18. How can the target audience affect mastering decisions?
Where will your product be heard? Is computer fan or disk noise a consideration when listening to it? Will this fight against your audio or can it be used as beneficial ambient noise?
When albums mastered in some specific way sell better than the others, the target audience expresses it's preferences in such a way. This affects mastering decisions commercially.
Also, the target audience relates directly to the music style. It is hard to expect the classic listeners to dream about louder records (more compressing).
19. What happens to the audio signal when a aural enhancer is applied?
Reproduced sound is audibly different than the original live sound because of the loss in harmonic detail, often sounding dull and lifeless. The Aural Exciter or enhancer adds harmonics, restoring the sounds natural brightness, clarity and presence, effectively improving detail and intelligibility. Using the Aural Exciter on specific instruments and/or in the final mix brings life back to the recording.
The Aural Exciter extends the high frequencies, unlike EQ’s and other brightness enhancers which only boost the high frequencies and alter the overall tonal balance. The stereo image is enhanced with the Aural Exciter, resulting in a greater perceived loudness without an introduction of noise into the audio path due to increased gain. Vocals and instruments seem to stand out, without raising individual volumes in the mix.
20. What does relative loudness mean?
The Relative Loudness levels are important insofar as they demonstrate that a 10-decibel increase will be perceived as twice as loud as the pervious level or conversely, a decrease of 50% from the previous higher level. It is less important to understand the physics of this relative difference as much as to accept it as an acoustical phenomenon.
Relative loudness adjustments are necessary to produce professional-sounding CDs.
21. What does r.m.s. mean?
Root Mean Square
The square root of the average of the squares of a variable quantity.
In terms of voltage, the root mean square voltage is called the effective voltage, as opposed to the peak voltage which corresponds to the maximum amplitude of the voltage variations. RMS power (in watts) is similarly called the effective power, since for an amplifier, for instance, it represents its real power.
22. What is meant by 'entertainment quality'?
I didn’t find any topic that explains this term. I suppose that must be the quality satisfaction felt by the consumer after listen the final product of a recorded CD????
23. What happens if you leave excessive, short transients in the music?
The impulsive low-frequency transient rises in 0.1 ms and lasts more than 1 ms. Its companion, the oscillatory low-frequency transient, contains frequency components up to 5 kHz. These types are the most common transients recorded on a power system. They are not only easily propagated but they can also be amplified by a power-system resonance phenomenon.
24. What is The K-System?
K-System is a metering and monitoring standard. It uses 0dB as a reference point which determines the monitor gain. Monitor gain is adjusted so there is 83 dB SPL at 0 dB. On the dBFS scale, the 0 dB point is either 20, 14 or 12 dB below clipping, depending on the K-System scale in use. The choice is between three scales, K-20, K-14 and K-12. The higher the number, the greater the headroom, given you keeps your average levels at 0 dB. What scale to use depends on the music and target environment? K-20 has a good dynamic range, suitable for symphonic and/or audiophile quality music. K-14 is suited for production intended for home listening, and the K-12 fits for productions for broadcast. The meter has a bar representing the average level and a moving line or dot above that representing the most recent highest instantaneous peak level.
25. What are The Equal Loudness Contours?
The ear is not equally sensitive to all frequencies, particularly in the low and high frequency ranges. The response to frequencies over the entire audio range has been charted, originally by Fletcher and Munson in 1933, with later revisions by other authors, as a set of curves showing the sounds of pure tones that are perceived as being equally loud. The curves are plotted for each 10 dB rise in level with the reference tone being at 1 kHz. Also called loudness level contours and the Fletcher-Munson curves.
The curves are lowest in the range from 1 to 5 kHz, with a dip at 4 kHz, indicating that the ear is most sensitive to frequencies in this range. The intensity level of higher or lower tones must be raised substantially in order to create the same impression of loudness. The phon scale was devised to express this subjective impression of loudness, since the decibel scale alone refers to actual sound pressure or sound intensity levels.
Historically, the A, B, and C weighting networks on a sound level meter were derived as the inverse of the 40, 70 and 100 dB Fletcher-Munson curves and used to determine sound level.
The lowest curve repesents the threshold of hearing, the highest the threshold of pain.
26. What is MetaData?
The slick definition of metadata is "data about data". Essentially metadata is any form of ‘tagging’ or codified identification used to describe an item of data. A useful description is the one provided by the Dublin Core Website:
The simplest useful definition of metadata is "structured data about data." This very general definition includes an almost limitless spectrum of possibilities ranging from human-generated textual description of a resource to machine-generated data that may be useful only to software applications.
The recording industry also disclosed that it is examining so-called "metadata" tags, hidden snippets of information embedded within many MP3 music files.
27. Explain the term Headroom.
Also known as headroom, attenuation crosstalk ratio (ACR) is the difference between attenuation and crosstalk at a given frequency along a cable. Measured in decibels, ACR is a calculation used in networking transmission to assure that a signal transmitted across a twisted – pair cable is stronger at the receiving end than any interference signals imposed on that same pair by crosstalk from adjacent pairs.
28. Explain the term Crest factor.
The peak-to-rms voltage ratio of an alternating current (ac) signal. The Crest Factor is equal to the peak amplitude of a waveform divided by the RMS value. The purpose of the crest factor calculation is to give an analyst a quick idea of how much impacting is occurring in a waveform. Impacting is often associated with roller bearing wear, cavitations and gear tooth wear.
In a perfect sine wave, with an amplitude of “1”, the RMS value is equal to .707, and the crest factor is then equal to 1.41. A perfect sine wave contains no impacting and therefore crest factors with a value higher than 1.41 imply that there is some degree of impacting.
29. What skills and abilities must a Mastering Engineer possess?
The recording engineer is the "knob turner" in the studio responsible for capturing the artist's performance. Typically the recording engineer is the main person behind the console, setting recording levels and making certain that all signals going to tape or the digital audio workstation are correct. The recording engineer must have an especially well trained ear to listen for any musical variations in tuning or tempo while the music is being recorded. Additionally the recording engineer must be aware of all recording levels and signal levels passing through the console and external signal processing devices. All session operations are under the purview of the recording engineer. The recording engineer also works with the producer on the final mix of the music.
30. What does the term “Masking” mean?
Masking is the phenomenon by which loud signals can prevent the ear from hearing softer sounds. The greatest masking effect occurs when the frequency of the sound and the frequency of the masking noise are close to each other.
This phenomenon is one of the main reasons that stereo placement and equalization are so important in the mixdown process. An instrument that sounds fine by itself can be completely hidden or changed in character by louder instruments with a similar timbre.
31. Explain the Hass Effect.
Also known as the precedence effect, this effect describes our ability to perceive the location of a sound source based on the relative level and arrival time of the sound in each ear. This phenomenon was first discovered by Helmut Hass.-
Sorry, I posted this also by mistake to the Mastering Practical. |
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Wed May 12, 2004 1:06 am |
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