Pre-Mastering / Mastering
Mastering has two definitions depending on which segment of the sound production process is actually being discussed.
In one context, Mastering (post production) is the creation of a a final copy of a composition (or group of compositions) prior to the transfer of the composition(s) to a media for release to the public. Mastering is also sometimes used in the context of creating a Glass Master that will be used to make copies onto the familiar, commercially sold plastic CD (CD Mastering).
Pre-Mastering (or post production) is your best-effort, final, mixed, edited copy of an individual or several compositions, in either DAT or CD format, that will be used as a source copy for replication purposes (which normally means producing either a CD or cassette copy). One may also submit the pre-mastered copy version to a Mastering Studio that may also be capable of replication (manufacturing thousands of copies of the composition in your desired format). The Mastering Studio may also re-master (re-edit) your pre-mastered copy. The Pre-/re-mastered copy is then etched into a glass Master copy by a laser cutter. The glass Master Copy is used to create a metal copy that is used as a stamper to replicate copies in the familiar plastic version. The stamped replication process is done onto the aluminum CD media which produces good results in most consumer audio devices. As music composition continues to migrate to an all digital distribution, Mastering will come to be defined more by its traditional idea of final editing of the composition.
In Mastering (post production final editing) it is expected that the final mix is reviewed and adjusted one more time by a professional engineer on superior editing equipment. It does not matter if it is one composition or several, the idea is to give each composition a consistent sound and presentation when it will be played back on consumer audio equipment. The level of equipment that one already owns, your level of experience, who the intended audience is and what medium (Audio CD, streaming media, etc.) will determine whether you should seek professional pre-mastering or not. With the quality of today’s home recording systems you can produce a fairly good demo for at least review by recording industry representatives. A Mastering company will, hopefully, have superior equipment such that if you send them an analog mix to tape then they can do the analog to digital conversion at 20-bit to 24-bit resolution and 48KHz to 96KHz sampling, compared to what one can do in a home studio. Again, it depends on your intended audience.
The Mastering is the final editing and processing (normalization, EQ, limiting, compression, stereo balance, fading) which are completed in order to make the composition consistent and eliminate any problems. If there is more than one composition, then they are placed in order, spacing between them is timed, and the level of volume across all compositions is established. It is still possible to introduce further editing (reverb, EQ, etc.). The source copy final version should be as perfect as possible as it is the version that you will be submitting to a professional manufacturer so that it could be replicated to create distribution copies for either further review or for sale.
Digital Data Transmission
Digital data signal or bit stream can be transmitted through / over:
- Unshielded Twisted Pair copper wire
- Shielded Twisted Pair copper wire
- Coaxial Cable
- Radio (Microwave and Infrared)
- Satellite
- Fiber Optic Cable (glass and polymer)