Thursday, August 21, 2014

All About The process of making an Audio CD

What Is Mastering?
You’ve poured your heart and soul into your music. It deserves that huge sound you’ve been dreaming about.
The mastering engineers at the SoundLAB at Disc Makers can give your music the soaring highs and booming lows it needs to compete against all the other releases out there.
So what is mastering? Every major label release is mastered to prepare it for radio play and retail sale. The reason? In the studio you record one song at a time, resulting in songs that all peak at different levels and have different EQs. A mastering engineer can unify your album with skillful use of EQ, gain, and compression to give it a consistent sound from track to track. This process also allows the mastering engineer to pump up the volume of your overall album so it’s as hot as can be and make it sound unbelievable.
With music mastering from the SoundLAB you can get the professional sound you want at a fraction of the cost. You’ll get the same exact treatment that perfectionists such as Eminem, The Roots, and Jason Newsted of Metallica fame have chosen. All for as low as $99 a song.
A fresh pair of ears can be the difference between a good-sounding CD and a great one. A real advantage of audio post production is that an unbiased sound professional has the opportunity to evaluate your master and determine how to get the most out of your production. After you’ve spent weeks or even months in a recording studiolistening to your CD over and over again, a fresh pair of ears of one of our mastering engineers can put the project into perspective for you, and let you know whether or not your CD will benefit from audio post production. After all, you only have one chance to make your music sound its best. The choice is up to you.
To improve your recording the mastering engineer can:
·        Raise the overall level.
·        Even out song levels and EQ individual tracks for cohesion.
·        Correct minor mix deficiencies with equalization.
·        Enhance flow by changing the space between tracks.
·        Eliminate noises between tracks.
·        Make your music sound great on any sound system.
·        Add your ISRC codes.
·        Add CD-Text information (Artist, Title, and Track Names that can be displayed by some CD players).
Making a CD generally involves four steps:
This is the process of capturing your performance onto a physical medium like tape or a computer’s hard disk.
This is the process of blending together multiple recorded tracks using a mixing console; the usual result is a two-channel, stereo performance.
In this phase, your audio recording is balanced, equalized, and enhanced so your finished product will be both more musical and more competitive in the marketplace.
In this final step, your digital audio master is transferred to a glass master and thousands of copies are made.
If you’re not mastering your audio recording, you are leaving out what could be a crucial step in the making of your CD. Your master is the template for thousands of your CDs to be produced for commercial release. CD mastering enables your recording to faithfully reproduce your vision, making it the most musical and commercially competitive it can be, by bridging the technological gap between the artist’s recording equipment and the listener’s stereo system. CD mastering can make a huge difference in the competitiveness and musical value of your product – and it is also the greatest bargain in the entire workflow of making a CD.
Those who have looked into professional CD manufacturing, you could not have failed to come across the term “Glass Mastering.”  We have been pressing CDs for decades now, but glass mastering still seems to be the most misunderstood phrase in the industry. To be honest it is not only the novice who is confused, many music industry long timers still only have a vague idea of what the process involves. In this blog I hope to dispel the mystery that surrounds the glass mastering process. If you are looking for detailed technical specifications on the process you may have to look elsewhere, this post is only going to cover the basic process in order to keep it short.

“What is glass mastering?”

Glass mastering is used to describe the process of transferring data from a CD/DVD Master to a metal stamper that is used to”press” the discs.

“So why is it called glass mastering?”

The first stage of Glass Mastering is to etch the 0′s and 1′s that make up the data on the master on to a piece of photosensitive film that has a glass disc as the substrate (base). This is done by a machine called a Laser Beam Recorder, this is a huge and highly accurate  version of the CD recorder in your computer. This glass disc with the information etched onto the film is then sent to galvanic processing to create a metal version, a stamper, of the information recorded on the photosensitive film.

“Why is it made of glass?”

The reason for using glass is that it is possible to get glass polished to a very smooth surface. This is vitallas any imperfections in the base will cause errors in the  CD manufacturing process. It is important to note that at every stage of making the stamper, each part is checked against the original CD master to ensure that it is an exact clone.

“What happens to the glass master after you make the stamper?”

After galvanic processing when we have a stamper, the glass substrate is washed down and re-used to make other stampers.

“As I have paid for glass mastering, can I keep the glass master?”

Afraid not, as we re-use the glass substrate to make other stampers. It would be a bit like ordering a cup of coffee from a cafe and then asking to keep the kettle that boiled the water.

“Can I keep the stamper?”

Generally speaking, no. The stamper contains nickel, this is a valuable material, and once we are finished with the stamper it is melted down and re-used. Beside this it would not be of much use to you, all the factory’s I know of would not be happy using a stamper that has been glass mastered by another CD pressing plant. In most cases the stampers are incompatible with the machines used in other plants. And due to the large amount of quality checks made throughout the manufacturing process the pressing plants prefer to work from their own stampers.

“How long do you keep the stamper, what if I want to re-press my CD?”

All factory’s retain the stamper for different periods of time for future re-presses. Most will keep the stamper for at least 3 years from the date of the last pressing and some will hold it up to 7 years. However these days pressing plants will keep a digital copy of the master stored on hard disc, so if after this time you want a re-press and they no longer have a stamper they can re-glass master the project.

“But my mastering studio has given me a glass master, why do I have to pay for glass mastering”

This is a common misconception. Mastering studios create “CD masters” and not  “Glass Masters”, it is the CD master given to you by your mastering studio that is used to create the glass master.

“Can you send my CD master back to me after you have made the stamper?”

Of course, this is your master, and once we have made the stamper and kept a copy of your CD master on hard disc, we no longer require the original master. One thing I will say that if you are looking to keep a safety copy of your disc, I would recommend keeping a factory pressed copy of the CD in a safe place. These are less likely to degrade over time, and will generally have lower errors compared to a CD-R master.

“Is it the glass mastering process that makes pressed CD’s better than CD-R duplication?”

Not quite, however it is the meticulous attention to detail in the glass mastering process that sets the stage for high quality CD pressing. There is much more to it than creating a high quality stamper, the two types of discs differ in many physical ways as well. To list all the differences is beyond the scope of this post, and it is an issue I would like to devote a an entire future post to. At this point I will just say the two formats are quite different in many ways, and CD duplication is not to be confused with high quality CD manufacturing.
So essentially that is a basic overview of glass mastering for CD manufacturing. Some of the points I have made may not apply to all CD pressing plants, so if you are not using Pure Music to manufacture your CD, I would check with your supplier directly with regard to how long they will keep the stamper and if they hold a version on hard disc for the future.
I hope you have enjoyed this post, and as always, if you have any questions regarding this article, feel free to drop me a line in the comments section, and I will do my best to give you an answer.
Both CD and DVD glass mastering require a laser beam recorder whereby a laser is used to expose minute areas of a photo-resist layer on top of a rotating glass master disc. The lengths and spacing of these areas is defined by the data to be stored on the disc. These areas are then developed to form pits and coated in a thin layer of nickel, on which a nickel Father is grown using an electroforming process. A Mother is then grown from the Father and the stampers grown from the Mother. The premastered data for the CD to be mastered is used as the input data during the glass mastering process. This process has several steps listed below.
Mastering of CDs and DVDs is a complex process carried out in a class 1,000 clean room. Operators wear special clothing including face masks and footwear to minimise particles that could affect the quality of stampers and therefore of pressed discs.
There are differences when mastering DVDs compared with CDs, mainly due to the smaller geometries and tighter specifications.


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