RedBook CD Standard
Whether you master with me here at MU-SPOT MASTERING or elsewhere, there are things you should know before making a disc for duplication and distribution. THE standard for compact disc masters is called RedBook. Here are the general specifications developed by Sony/Phillips, who brought us CD technology:
Allows for up to 74 minutes of digital sound
Sample rate of 44.1Khz, or 44,100 samples per second
Transfer rate of 150 kilobytes per second. Also known as "single-speed" or 1X
Can contain up to 99 tracks
RedBook audio is also referred to as CD-DA (Compact Disc-Digital Audio). Introduced by Sony and Philips in 1980, the RedBook standard was simply designed to be a universal medium for distributing digitized music
Data on a audio CD is organized into frames. Each frame contains up to 24 bytes of user data, synchronization, LECC (Logical Error Correction Code), and data for control and display. Frames are interleaved with other frames into a single, spiral so that scratches or defects will not destroy a single frame beyond correction. Rather, a scratch will destroy a small portion of many frames, all of which can be recovered in other frames.
A RedBook disc is divided into three areas: Lead In, Program, and Lead Out. Every track's location is recorded into the disc's TOC (Table of Contents) which is stored in the Lead In area of every disc. The RedBook CD was to become the template for which all other "book standards" were created, and all of them (predictably) sport a 'color' moniker.
There are tales about on the web of folks using a "home computer" program to make a master for duplication and subsequnet distribution, only to find the discs they sold would not play in most of their customers' players! Not all disc burning software will do RedBook standard. Don't let this happen to you!
Using quality media, professional software, and a high-quality CD burner can assure you that you get EXACTLY WHAT YOU NEED! These are all part of the mastering services here at Blantone Music's Mu-Spot Mastering.
I check, recheck, and triple-check the master disc's quality for errors to ensure that you are getting the absolute highest quality product. A printed, signed, verified quality report comes with every Blantone Music master disc. I will reject any disc that does not perform in the highest 2% of error rate quality. There are three major categories of CD errors. Below is a brief rundown of each.
Types of CD Write Errors
Excessive authoring/writing errors can result in the failure of a CD to perform as it should. The folks that run the major CD duplication houses, and for me here as well at Blantone Music, will indeed reject master discs that contain authoring errors which exceed what the specifications allow. As a matter of course here, exceeding the quality imposed by the RedBook standard ensures that your master will perform flawlessly! These errors are listed in ascending order of importance relative to a disc's quality.
1) C1 Errors
C1 Errors are anomalies in the block error rate (BLER), which are bit-burning errors at the lowest measurable level, making these the least serious of the error types. This rate is rendered as errors per second. EVERY CD and CD-R contains THIS TYPE OF ERROR. These usually result from the CD burning process, but faulty media can also cause these to occur. Keeping these errors below an acceptable average of 220 errors per second is the standard here. My own standards here, then, allow me to provide you with master discs that come in well below the RedBook standard minimum. The quality report shown here* reflects a C1 average error rate of only 0.22 per second! The total number of C1 errors for this disc was 558 for 41 minutes running time!
2) C2 Errors:
C2 Errors are a "bit" more serious, and can render a disc unplayable. Some CD players can correct these upon playback, but not with all players and not with all discs. C2 errors generally indicate poor quality media was used in the write/burn process. Master discs produced here contain absolutely no C2 errors. Media choice in making the master disc is extremely important! If you are going to burn your own master disc from files delivered digitally to you from Blantone Music's Mu-Spot Mastering, feel free to communicate with me on what your best choices in media are.
3) CU Errors:
CU Errors are the most serious and without exception cause a disc to be unplayable/unusable. These errors occur after a disc player has tried to correct C2 errors and has failed in doing so. This generally means that some data has been lost on the disc and cannot be recovered by the playback mechanism.
These three types of errors are all related to the digital information on the disc. Sometimes (and we've all seen it), a disc becomes physically damaged. For instance, it doesn't take long to damage a disc having left it floating around in a car without its case! Errors that are the result of physical damage can sometimes be corrected via CIRC Logic, or Cross Interleaved Reed-Solomon Code (but not always). CIRC is part and parcel to CD playback mechanisms. It's always a good idea to make archival copies of any digital recording that you wish to preserve!
A CD master disc measuring less than 220 C1 errors per second, is technically "good" master. Here at Mu-Spot Mastering, my masters average less than 1 C1 error per second with absolutely no C2 or CU errors. My own standards here further indicate that in addition to any master disc containing no C2 or CU errors, I will not ship any disc that averages more than 1 C1 error per second. That's .0045% of the maximum allowed for a good quality disc. This results in an excellent master of the very highest quality. If you're going to have your CD replicated professionally , accept no substitute for a high-quality master provided by any reputable, professional mastering outfit. While CD mastering is obviously very concerned with EQ, dynamics, song levels, etc., it's also about providing you with a quality master that will be accepted by ANY professional CD replicator. I test each master for errors and provide you with full documentation on its quality*.
*this service applies only to masters authored and executed here at Blantone Music's Mu-Spot Mastering through my standard FULL SERVICE mastering
Are your songs destined for digital distribution?
Does your master need ISRC codes? It may!