Here are the answers:
1. Which came first- audio CD's or CD-ROM?
Audio CD's were first by several years. Early CD-ROMs had a protective case that could be
inserted in the drive bay like a 3-1/2 floppy.
2. Name the two companies that teamed up to create the CD.
Sony and Philips (also known as Magnavox in the US).
3. Name the title and artist of the first audio CD release.
52nd Street by Billy Joel (a Sony claim).
4. Opposite of vinyl, CD tracks start at the center and go out- this was because the final diameter
of the medium had not yet been decided in the early prototype stage. A maximum diameter was later
established based on a specific equipment size limitation- name the equipment.
In-dash car stereo gear- early CD players were huge boat anchors, but designers planned for the future.
5. Early CD's had a maximum playlength approaching 74min- why was this important?
To deliver Beethoven's 9th Symphony uninterrupted, which averages 72min. 80min CD's are now the standard,
but headroom was built in early on, so most players can handle the 80min discs just fine.
6. Vinyl LP's spin at a rate of 33 1/3 rpm- what about CD's?
The rpm varies- near the beginning (center of the disc) the speed is about 500rpm, and slows to about
200 rpm near the edge; the idea is to maintain a uniform, optimized data density. One of the setbacks
of vinyl is that the rpm is constant and signal in the inner grooves is packed tighter, making it more
difficult for a stylus to track at the highest frequencies.
7. CD's can accomodate up to 99 tracks, but there was also an optional feature within tracks, supported
by many players up until the mid 90's- what was it?
Indexing! This feature was designed for long audio tracks, often found in classical music. A symphonic
movement, stored as one track can range from 10 to 20min- indexing allowed for one-touch cueing of
individual melodies within a large track.
8. What is 'emphasis' as it applies to audio CD's?
Emphasis is an encode/decode noise reduction method that has been used in recording long before CD, it
is also used in FM radio. Before recording, high frequencies are boosted (like cranking a treble control);
a complimentary lowpass filter is used in the playback device to restore the tonal balance. Emphasis increases
signal-to-noise ratio at high frequencies and significantly reduces background hiss.
In early recordings, Denon (and maybe a few others) employed emphasis in CDs not for noise reduction, but over
superstitious concerns that digital audio with its finite resolution might not be able to convey the most subtle
details without a little help. Players have de-emphasis circuits that kick in automatically when needed. The
problem is when you copy one of these discs- the emphasis flag is lost, resulting in a bright sounding copy.
If you rip to wave, you get the same problem.
9. What's the difference between CD-R and CD-R Audio?
A binary tag, and a price tag. On a computer, CD-R & CD-R Audio burn equally well, and the result works on most
players. CD-R Audio discs are a bit more expensive, but are required by many stand-alone component CD recorders.
A portion of the extra proceeds go to folks like Phil Collins, Madonna, and the rest of our friends in the recording
industry...
