a lot more to recording a CD than just pressing "record"!
Ever wonder what really ends up on those shiny round discs? In Part
I of this two-part series, you'll learn about the physical and logical
workings of the medium, while being treated to a "written-in-plain-English"
overview of data storage and retrieval, CD formats, encoding, error
correction, subcodes, and more. As recording and mastering engineer
Lionel L. Dumond shows, there's more to a recorded CD than meets
my very first honest-to-goodness studio gig. It was an eight-track room
with carpet on the walls, egg crates on the ceiling, and an ancient Tapco
board. The year was 1980, back when a digital audio recorder cost more
than a downtown building, "ADAT" was something your deaf grandfather
would mutter whenever anyone said something to him, and the compact disc
was just coming out of the laboratory.
Mostly, I recall the frustration of getting test pressings back that didn't
sound anything like I expected they would. No bottom end, mushy highs,
the dynamic range squashed. To me, they would just sound dead compared
to the mix we had sent. Add to this the fact that these test pressings
weren't even the real thing -- they were acetates, made of soft plastic
that held up to about a half-dozen good spins if you were lucky!
You see, back in the day when vinyl was still king, producing a real "master"
in a local recording studio just wasn't possible. Once we as producers
and engineers had taken our best shot, the final step in preparation for
pressing involved shipping the two-track reels to some mysterious, far-away
place where a mastering engineer would take over. Part of the mastering
engineer's job was to apply equalization and limiting -- not necessarily
to make the music sound better, but so that a low-frequency passage wouldn't
make the needle jump a groove, or a hot peak wouldn't blow the head off
a cutting lathe. Depending on the skill and conscientiousness of the mastering
engineer, the results could range from decent to disappointing. This was
something we pretty much lived with at the time. Unless you owned your
own record factory, you and your master were at the mercy of the man at
I remember wishing back then that I could get my hands on my own master
thanks to modern recording technology, things are different today. With
the advent of digital audio technology has come a revolution in the way
music is recorded and distributed. The introduction of the compact disc
removed the physical constraints of styli, turntables, and PVC from the
playback medium, making the mastering of records much more an art than
a mechanical process. And with the subsequent introduction of CD-R --
the recordable CD -- it became possible for the recording engineer, working
in a regular facility, to actually receive a copy of a work (or create
one himself) in an format virtually identical to the final product.
No more cheesy acetates! Heck, this is better than owning a record-cutting
lathe -- and all without the several tens of thousands of dollars it would
have taken to buy one in the old days!
But of course,
with this new technology came new issues to deal with and new things to
learn. I soon figured out there's a lot more to recording a CD than pressing
techniques, and uses of recordable CD in audio production is a complex
subject, and often a source of confusion for the uninitiated. It's important
to remember that compact disc is, by its very design, a digital chameleon,
which is what it's developers intended. A CD (and by extension, a CD-R)
can contain audio, video, photographs, computer programs, data files of
any type, or a combination of any or all of the above, contained in any
number of different physical and logical formats. Of course, as the types
of digital information stored varies, the recording methods used will
vary as well.
In this article,
we explore the subject of CD recording as it pertains to audio production.
In Part I, we'll present a brief theoretical overview of CD data encoding,
storage, and retrieval. In Part II, we'll tackle various hardware and
interface options, and explore some of the more useful recording methods
and technologies. We'll also define some of the most commonly-encountered
technical terms as we go along.
How CDs Work -- An Overview
A compact disc nothing more than a physical medium used to store binary
information. In this regard, it's no different than a floppy disk, the
hard drive in your computer, or a DAT -- it's merely a way of storing
a long list of ones and zeros. What makes a CD -- and for that matter,
any other digital storage medium -- unique is the way in which the data
is written, arranged and accessed. While a very technical explanation
of how this is done would exceed the scope of this article, a simplified
presentation is in order.
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