RECORDING YOUR OWN CD-R's
by Bruce Bartlett
Right on your own desktop, you can make a compact disc by using
a CD-R recorder. The disc will play in a CD-ROM drive or audio
CD player. It's exciting to hear one of these CDs playing your
music with the purity of digital sound.
CD-R stands for Compact Disc Recordable. This optical medium
is a write-once (non-erasable) format. Sound quality meets or
exceeds compact disc standards, and the expected lifetime is
about 70 years.
Erasable CDs are called CD-RW (re-writable). CD-RW discs cost
more than CD-R discs, but CD-RW discs can be used over and over.
Currently, a CD-RW disc will play only on a CD-RW recorder, not
on a standard CD player (but this may change).
How can you use the CD-R format? Well, you could make demos
that sound much cleaner than cassettes. Or make a one-off copy
of your stereo mixes for clients. Use the CD-R as a premaster to
send to a CD replicator. Another function is to compile sound
libraries of production music, samples, and sound effects. The
CD format is a more dependable storage medium than DAT, so it's a
great way to archive your recordings.
EQUIPMENT NEEDS
Want to try CD-R? First you have two basic choices of CD-R
recorder:
- A standalone CD-R recorder, sometimes called a consumer CD
recorder.
- A computer peripheral CD-R recorder, also called a CD-R drive.
You plug it into your computer system.
Both types produce discs that sound equally good.
The standalone CD recorder has everything you need in one
chassis. Inside is a CD transport, laser, and microprocessor.
On the back are analog and digital ins and outs. On the front
are the level meters, record-level knob, display and keypad.
Because the standalone unit needs no external computer, it's
user-friendly. Just connect your audio source containing an
edited program, either on DAT or analog tape. Set the recording
level and start recording.
In contrast, with a computer CD-R drive you need to copy your
edited DAT program to your hard drive, then copy the hard-drive
recording to CD-R. This takes longer, but the computer CD-R
recorder costs less than the standalone recorder.
Here are the features of both types of CD burner:
Standalone CD recorder:
- Costs about $600 and up.
- Does not require a computer.
- Writes audio but not data.
- Most use "Consumer Audio" blank discs costing about
$3-5.
- Makes CD-R and CD-RW discs (if CD-RW is included).
- Records at realtime speed.
Computer CD recorder:
- Costs about $200 and up.
- Requires a computer, at least 16 MB RAM, sound card
(16-bit/44.1K), CD-R software, and a 1 GB or bigger hard drive
with 680 KB/sec minimum throughput.
- Requires a fairly fast computer: Pentium 100 or faster, Mac
Centris, Quadra or Power Mac with 8 MB of RAM.
- Plugs into an IDE or EIDE ribbon cable or SCSI card. EIDE works
as well as SCSI if you don't run other programs in the
background.
- Writes audio and/or data.
- Uses 74-minute (750 MB) CD blanks costing about $1-2 each.
- Makes CD-R and CD-RW discs (if CD-RW is included).
- Records 2X to 6X normal speed. Best choice for multiple copies.
- Can be internal or external.
If you want to burn more than one CD at a time, you can
daisy-chain CD-R recorders together, or use a tower CD-R
duplicator.
CD-R TECHNOLOGY
While conventional CD players follow the Sony-Philips Red Book
standard, CD-R conforms to the Orange Book part II standard.
Once recorded, a CD-R disc meets the Red Book standard.
A recordable CD is the same size as a standard compact disc,
but is more colorful. On top is a layer of gold; on the bottom
is a recording layer made of blue cyanine dye. Actually, the
blue layer appears green because of the gold layer behind it.
Some CD-R discs use a yellow (gold) dye of phthalocyanine.
Yellow dye lasts a little longer in accelerated aging tests, and
it may work better with high speed CD-R drives. Still, most CD-R
writers are optimized for cyanine dye, which can handle a wider
range of laser power and wavelength.
A blank CD-R is made of four layers:
- Clear plastic layer for the label (protects the gold layer)
- Gold (reflects laser light)
- Dye (for the recording)
- Clear plastic (protects the dye layer).
The dye fills a spiral groove which is etched in the bottom
clear-plastic layer. This groove guides the laser.
To record data on disc, the laser melts holes in the dye layer.
The plastic layer flows into the holes to form pits. During
playback, the same laser reads the disc at lower power. At each
pit, laser light reflects off the gold layer. The reflected
light enters the laser reader, which detects the varying
reflectance as the pits go by.
In contrast with a standard CD, a CD-R disc has two more data
areas:
- The Program Calibration Area (PCA). The CD recorder uses this
area to make a test recording, which determines the right amount
of laser power to burn the disc (4 to 8 milliwatts).
- The Program Memory Area (PMA). This area stores a temporary
table of contents (TOC) as the CD-R tracks are being assembled.
The TOC is a list of the tracks, their start times, and the total
program time. The recorder uses the Program Memory Area for this
information until it writes the final TOC.
CONFIGURATIONS
Before we look at the differences among CD-R recorders, we need
to understand the concept of a "session." A session on disc is a
lead-in, program area, and lead-out. Each session has its own
TOC. Each lead-in and lead-out consume 13.5 MB of disc space.
With the "Multisession" feature, you can write several sessions
on a disc at different times. This feature comes in handy when
you need to add information to a disc a little at a time. Only
the first session on disc will play on an audio CD player, so the
discs are just for your own use -- not for distribution.
Some CD-R recorders permit "Disc-at-Once" recording, in which
the entire disc must be recorded nonstop. You can't add new
material once you write to the disc. With the right software,
Disc-at-Once lets you set the length of silences between tracks
(down to 0 seconds), and lets you control how the tracks are laid
out on disc. Disc-at-Once is the pro audio format.
Most CD-R recorders allow "Track-at-Once" recording. They can
record one track (or a few tracks) at a time -- up to 99 tracks.
You can play a partly recorded disc on a CD-R recorder. But the
disc will not play on a regular CD player until the final TOC is
written. Track-at-Once is not recommended for audio because it
puts 2-second spaces and clicks between audio tracks.
If you want no pauses between tracks (as on a live album), get
a CD-R recorder with Disc-at-Once, and some software that can
adjust the pause length down to zero. Note that a standalone
CD-R recorder will copy your edited program as it is, with or
without pauses.
Other things to look for: a buffer of at least 1 MB and
high-speed CD-RW formatting (5 minutes or less). Be sure that
you can return the CD-R writer if it proves to be unreliable.
BLUE DYE vs. GOLD DYE
As we said, a blank CD-R disc contains a layer of dye in a
preformed spiral groove. The laser burns pits in the dye. Two
types of dye are in use: blue or gold. The blue dye, which
appears green because of the gold backing, is Cyanine. The gold
dye is Phthalocyanine.
What are the differences? Mitsui claims that gold dye is more
durable and reliable than blue dye when exposed to heat,
humidity, and light. "Unlike a Cyanine based CD-R, which shows
degeneration from continuous exposure to light and heat under
Carbon Arc Lamp testing, Mitsui's Phthalocyanine based CD-R
remains durable and remarkably stable throughout the entire test
exposure time of 180 hours.
"Mitsui CD-Rs' projected longetivity was tested by employing
the Orange Book Standard for Block Error Rate (BLER) set by the
industry for CD-Recordable media. The Phthalocyanine-based
Mitsui CD-R was subjected to 80 degrees Celsius and 85% RH for
over 1000 continuous hours, the equivalent of more than 100 years
under normal use. The Mitsui CD-R was consistently able to
retain data and outperform the Orange Book Standard."
According to Dana Paker in the Incat Systems Web pages,
"Cyanine dye is the de facto standard; the Orange Book was
written based on the original cyanine dye discs from Taiyo Yuden.
Most CD-Recorders are optimized for cyanine dye. Cyanine discs
are compatible with a wider range of laser powers.
- Phthalocyanine dye has performed better than cyanine dye in
accelerated age testing, and may work better in higher speed
recording (which requires higher laser powers.)
- However, all of these differences aside, it appears that in
most cases, the two types of discs perform in essentially the
same ways -- it's at the extremes and in the worst-case
scenarios where these differences appear most marked.
HARD DRIVE
When you prepare an audio program for transfer to a computer
CD-R drive, you first have to dump the audio to hard disk. Audio
consumes a lot of space. A 74-minute audio program fills 750 MB.
So a hard drive of at least 1 GB is recommended, with a
throughput of at least 1000 KB/sec. The audio data should be on
its own separate drive or logical drive. You could divide the 1
GB drive into two logical drives: Drive C could be 200 MB for
programs, and Drive D could be 800 MB for audio.
Most hard drives do a thermal recalibration every so often.
This pauses the hard-disk operation up to 1.5 seconds, which
causes errors in CD writing. You want a hard drive that
postpones thermal recalibration when the disk is in use. This
type is called an A/V (audio video) drive.
CD-R EDITING SOFTWARE
The computer CD-R drive requires a CD recording program,
usually packaged with the recorder. You don't have to use that
program; other ones are available that you might prefer. Be sure
the program is compatible with your recorder. Most software
requires at least a Pentium 100 computer with 16 MB RAM.
There are many CD-R recording programs, but only a few are
meant for audio. Most audio CD-R software allows Disc-at-Once
recording and PQ encoding. Disc-at-Once lets you set the length
of pauses between tracks, or eliminate them. PQ encoding is the
timing info for tracks on an audio CD.
To control the length of pauses between songs on the CD, you
need a CD-R recorder with Disc-at-Once in its firmware, and
software that allows Disc-at-Once writing. The Track-at-Once
feature is undesirable: it always puts a 2-second gap and a click
between songs. The click is caused by a .wav editor which adds
ASCII data to the end of the .wav file. Usually this data is the
name of the editor software and the creation date. To prevent
this, go to the Options menu in the .wav editor and turn off that
function.
Be sure that your CD-R software lets you control the length of
silent spaces between songs, down to 0 seconds (for crossfades
between songs, or for live recordings without a silence between
songs.) Also make sure that the software will work with your
model of CD-R recorder.
HOW TO USE A STANDALONE CD-R RECORDER
Let's say that you've compiled a DAT of song mixes. You want
to copy them onto a CD by using a self-contained CD-R writer.
The first step is to edit your mixes into a finished program. To
do this you'll need a sound card and a 2-track digital editing
program. Here are the steps:
- Connect your DAT recorder to the sound card. Transfer your
mixes from DAT to hard disk.
- While viewing the soundfile waveform, mark each song as a
region (a selected segment of audio). Using a mouse, fine-tune
the start and stop points of each region so that there are no
noises between songs.
- Assemble the songs in order into an Edit Decision List (a
playlist or cue sheet). The total playing time should be under
74 minutes to fit on the CD-R disc.
- Between songs, put silent spaces or crossfades. Three to four
seconds of space is typical.
- Have the computer change the level of songs that need it.
- Start recording on your DAT. Play the cue list off the hard
drive and copy it to DAT.
- Once your edited program is on DAT, write a start ID 1/2
second before each song. Renumber the program numbers.
Now you're ready to play the edited DAT into the CD-R recorder.
Connect the DAT's output to the CD-R recorder's input. Set the
level and begin recording. Your program will copy to disc in
realtime.
Depending on the CD-R recorder, the DAT start IDs may or may
not convert to CD track numbers. If not, you can use a converter
box, or add the track numbers manually while you record.
Here is a typical procedure for burning a CD with a standalone
CD-R recorder:
- Select whether you want to increment tracks manually or
automatically.
- Select whether you want the recorder to go into record mode
automatically when the first Start ID comes in (assuming a
digital source).
- Insert a blank CD. The recorder will calibrate for the
optimum recording power.
- Select analog or digital source.
- Press RECORD to go to record-standby mode. If your source is
analog, adjust the recording level.
Make sure that your presets and connections are correct; you
are about to record the disc! It is a write-once operation.
- Press PLAY to begin recording, and start your source. Or if
automatic recording is on, just start the source. The CD-R
recorder will begin recording when it sees the first Start ID.
- Increment the tracks manually if you set the CD recorder for
that mode.
- When done, press STOP to end the recording.
At this point, you can record more tracks if you wish. Each
track can be from an analog or digital source.
When the recording is complete or the disk is full, press
FINALIZE and RECORD. In two minutes, the unit records the final
table of contents and the disc leadout.
There is your finished CD. It really is that easy.
HOW TO USE A CD-R DRIVE
The procedure for this type of CD-R is different. First make
the right connections. If your hard drive and CD-R drive are IDE
or EIDE, plug the CD-R drive into the IDE/EIDE ribbon cable. If
your CD-R drive is SCSI, plug it into your SCSI adapter card and
terminate the SCSI port on the CD-R drive.
You also need to make audio connections. If your mixes are on
DAT, plug the DAT's digital output into your sound card's digital
input. If your sound card has no digital input, plug your DAT's
analog output to your sound card's analog input. Other sources
can be analog tape, LPs or cassettes. Just connect the analog
source signal to the sound card's analog input.
You'll need two types of software: audio-editing software and
CD-R recording software. The first type records .wav soundfiles
on your hard disk, and lets you edit them. The second is used to
select and sequence the .wav files, and to transfer them to CD.
Some software can do both functions.
Let's say you've recorded a number of song mixes on tape, and
you want to transfer them to a CD-R. Depending on your software,
you can prepare your audio program in one of three ways:
- Option 1. Record each mix to hard disk as a separate .wav file.
Use your software to trim the start and stop points of each .wav
file (remove noises and silence before and after each song). You
might want to defragment the hard disk after recording the .wav
files so that the disk can be read faster. Arrange the .wav
files in order in a playlist.
- Option 2. Start with a tape of unedited song mixes. Copy all
the mixes to hard disk as one long .wav file. Then have the
program break it into separate .wav files, one per song. Launch
the CD-R software. Arrange the .wav files in order in a playlist.
- Option 3. Start with a tape of unedited song mixes. Copy all
the mixes to hard disk as one long .wav file. Using a digital
audio editing program, edit the program to adjust the silent gaps
between songs. In the edited program, note the start time of
each song. Write down these times. You will use them to create
a playlist.
Save the edited program as a new soundfile on disk, or copy the
edited program from hard disk to DAT. If you did the latter,
copy that edited DAT program back onto hard disk as one soundfile.
Launch the CD-R software. Then create a playlist that notes
the start time of each song within the edited soundfile.
Actually, rewrite each start time about 1/4 second before the
song starts, so that the CD player will play your CD-R without
missing the beginning of each track. You are creating markers or
pointers to define track IDs. Your finished CD should have the
same silent gaps between songs that are in your edited program.
The total playing time of the playlist must be less than the
CD-R maximum length of 74 minutes.
BURNING THE CD
Now that your program is in final form, it's time to write the
CD. If necessary, blow dust off the laser lens. Turn on your CD
recorder and make sure your computer has recognized it. Insert a
blank disc.
Any data interruption during CD writing can cause errors. So
before you record, turn off any TSR programs, screen savers,
networks, alarms, reminders, anti-virus programs, and incoming
faxes. In a Windows computer, select Control Panel/System/Device
Manager/CD-ROM. Select your CD-R device, click on the Settings
tab, and turn off "Auto Insert Notification."
At this point, you are almost ready to burn a CD-R. If you
select "On-the-Fly" mode, the computer will read your soundfiles
from random locations on your hard disk and will put them in
order as the CD-R does a burn. Caution: this process has a
relatively slow data transfer rate if your computer or hard drive
are slow. This slow throughput might cause "buffer underruns"
which create disc errors.
However, you can prevent this problem by telling the CD-R
software to write a "Disk Image" file first. An image file is a
single file containing a copy of all your sound files, in the
order you specified in your playlist. You'll need up to 750 MB
of FREE disk space for the image file. The computer will copy
the image from hard disk to CD-R during a burn. As the image is
written, the recorder light might flash, but the laser is running
at low power to avoid burning pits.
If your CD recording software reads one continous soundfile
from your hard drive and writes it to CD using pointers for start
IDs, you probably don't need to make an image file. Just write
the CD-R.
Creating a CD on the fly (without an image file) takes no extra
disk space, but it requires a fast Pentium to prevent errors with
high disc speeds.
Most CD-R drives can burn discs at 1 or 16 times normal speed,
and read discs at 6X to 24X normal speed. High speeds do not
degrade sound quality. Contrary to intuition, high-speed CD-R
writers create discs with fewer errors. How can this be? At
high speeds, the laser burns for a shorter time and so has less
time to drift. Also, the rapid high-power heating of each pit
creates sharper pits, which are more readable. A writing speed
of 2X is said to be the most reliable.
When you're ready, begin the transfer to the CD-R disc. The CD
recorder will burn the tracks according to your playlist, with
the specified track numbers, song order, and spaces between
songs. You can check how the transfer is going by looking at the
display on your monitor screen. As soon as the recording is
done, the display will indicate that the TOC is being written.
Finally the CD-R drive will eject the disc when it is done.
Now you have a finished CD. To prevent error-causing
fingerprints, be sure to handle the disc only by the edges. Pop
the disc in an audio CD player, press Play, and check that all
the tracks play correctly. Do not expose the disc to prolonged
sunlight. You can burn more discs of the same program, or start
over with a new one.
CD-R LABEL EDITORS AND APPLICATORS
Once your CD is written, label it on the gold side with a
water-based pen such as a Sharpie. Or you might want to label
the CD with a neat, disk-like label of your own design. You need
some blank CD labels, a label applicator, and label-design
software. Some software can also print liner notes, including
the track numbers, titles, and timing.
Some engineers prefer to label the CD-R blank before they burn
the CD. An off-center label can unbalance the disc and cause
data errors, so it's better to know that before burning than
after.
Here are some makers of CD labeling products:
- Neato Media Labeling Products, 888-575-3873, 203-466-5170,
http://www.neato.com.
- PressIt CD Labeler Kit by Rocky Mountain Traders, phone
914-359-0689 or 406-549-4445, www.mvd.com/pressit.
- The Label Applicator by Pro Source Sales & Marketing (no
software), phone 800-903-1234.
- Great Gizmos Stick-it Right CD labeler kit.
- Avery 5824 Laser CD-R Disc Labels.
- Memorex CD Labeling Kit
- CD LabelCorp offers blank labels and an applicator.
- Rimage Corp. makes the Perfect Image CD Printer, a standalone
printer that prints directly on the CD disc. $3995, 612-944-8144
or 800-445-8288.
- Fargo Electronics makes the Signature CD Color Printer, also a
standalone printer that prints directly on the CD disc. $1295,
distributed by Microboards Technology, 612-470-1848,
www.microboards.com. It must use specially coated CD-Rs.
BLANK CD-R DISCS
These are made by TDK, Verbatim, Kodak, Taiyo Yuden, 3M, Sony,
Maxell, Memorex, Mitsui, and others.
BOOKS ABOUT RECORDABLE CD
"The Complete Recordable-CD Guide" by Lee Purcell and David
Martin, SYBEX, Inc., 800-227-2346.
"Recordable CD Bible" by Mark L. Chambers, IDG Books Worldwide,
Inc., 415-655-3200.
WEB SITES ABOUT RECORDABLE CD
www.osta.org,
www.cdpage.com,
http://ghost.rssi.ru/public/hardware/cdrw/faq.htm,
www.cdarchive.com/info
Copyrighted 1999 by Deltamedia. May not be reproduced in whole
or part without permission.
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