RICK FITZPATRICK said:
but what I still don't understand is the correct way to set up the MIXED "sub-master" that you send to the mastering house.
Aaah, okay, I misunderstood. Must be leadfumes from soldering
All audio CD's are "redbook" CDs.
The first CD format which defined the music CD that could be played in all standalone CD players was called CD Digital Audio, CD-DA or just CD-A. The specifications for the CD-A format were set out in the 1980 "red book" standard developed by Philips and Sony. The Red Book standard specifies the data format for digital audio and the technical specifications for devices and media. It's called "Redbook" because the binders that were passed out with the documentation, were red, and the name stuck.
The CD-DA format standard dictates a sample rate of 44.1 kHz, with each sample being 16 bits long. As a result, one second of stereo sound uses 176,400 bytes of disk space. The data is stored in 2,352 byte data blocks along with error detection/correction and control data thus requiring 75 blocks for each second of audio playback. Since a standard 74-minute CD will hold about 747 MB we can determine that a minute of uncompressed audio takes about 10 MB of disk space.
Using "Pulse Code Modulation" or PCM, the music data in digital form is read off the disc. The player then converts this information into a normal binary form and passed to the DAC which feeds analog to the pre-amplifier stage, etc. By nature, an analog signal pattern follows a fairly predictable path, so it's a simple matter for the player to correct small errors, or compensate if a little bit of information is missing or cannot be read.
Additional Redbook Audio Specifications:
- Maximum playing time is 78 minutes (including pauses)
- Minimum time limit for a track is 4 seconds
- Maximum number of tracks is 99
- Maximum number of index points (subdivisions of a track) is 99
with no minimum time limit
- International Standard Recording Codes (ISRC) should be recorded
on CD-Rs to appear on the replicated discs
Actually, the redbook specification has a lot more to do with the physical dimensions than anything else. CD disk size, thickness, hub diameter, depth of layers, length and shape of "pits" in the plastic, etc.
At the time, 44.1Khz and 16-bits was decent technology. Since then, maybe, 8 billion players have been manufacturered? Maybe? Its more than three
Later developments in sampling technology now allow sampling at 192 kHz with bit depths of up to 32 for even better than "CD quality". However, the Redbook standard is now cast in concrete and the market is now flooded in Redbook standard audio CD players. Though the standard could be expanded to include higher sample rates & bit depths, it's probably not feasible. Consider that sampling at higher rates and/or bit depths, result in much larger files. Since standard Redbook audio CD's can hold up to a convenient 74 or 80 min depending on the media, sampling at higher rates/bit depths will result in much larger data files...... Thus a CD would not be able to hold anywhere's near 74 minutes of program. The CD medium simply hasn't the storage capacity to accommodate the larger file sizes. Add to those considerations the additional cost of manufacturing a CD player to handle all the different sampling/bit depth combinations. Then also consider that the millions of original Redbook players in the marketplace today would not be able to read the new higher sample rate/bit depth audio CD's. No one in the recording industry would want to commit economic suicide by releasing a CD that only the few folks with the newest hardware could play. At least so far.
So to answer your question... you send them a redbook CD, and they create the glass master from that.
BTW, if its not obvious by now, anytime you burn a CD with audio tracks that's playable in your home CD player, you've just created a redbook CD
So, that's the format the glass master is created from, and duplicated to your heart's content.
Now to answer your question (Don't you just love long-winded posts?)...
The format you send the material in to your mastering house, depends on what they will accept. All accept CD's, most accept DAT's, and some of the smaller houses will take almost anything. Some still take Otari tape for instance... but with the potential for damage in transit (temperature, humidity, demagnitization, etc), why not send it digital.
. Oh well... same ole story.....if I don't find it, I make it. Usually. BTW frederic, I'll be emailing you soon about your TMD's and midi. Since YOU are the expert. 
Ha. My lexicon Core 32 was obsolete within a year. Still haven't even really used it. What a joke. AND waste of money, although the PCI 90 reverb card is probably still pretty good. Haven't even heard it though.
Ok, thanks again.
