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ansermetniac ansermetniac is offline
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Default CD-RWs in the car

1) Why don't they work
2) How much more would the unit cost to make if it did


And

How much more would my KIA CD player cost to make if it advanced and
reversed within a track. BTW I thought this unit was broken so I
called the dealer for the replacement cost--$867. He said he was not
kidding. I fixed it myself.

Abbedd
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Richard Crowley Richard Crowley is offline
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Default CD-RWs in the car

"ansermetniac" wrote...
1) Why don't they work


Because they have lower contrast than CD-R or moulded CD discs.
But CDRs cost only a few cents each, so why bother with CDRW?

2) How much more would the unit cost to make if it did


Probably a few dollars (at design time).
Hundreds of dollars by the time it gets to the end-user (you).

How much more would my KIA CD player cost to make if it
advanced and reversed within a track.


Much more than just replacing it with a unit that has the features
you want.


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Dave Platt Dave Platt is offline
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Default CD-RWs in the car

1) Why don't they work

CD-RW discs use a "phase change alloy" as a way of storing information
(the ones and zeros). The alloy is changed between a crystalline, and
an amorphous phase by the laser which writes the data onto the disc.
This is a different method than is used in CD-R discs (which use a dye
layer that is actually "burned" by the laser) and manufactured CDs
(which uses molded pits).

Although the two alloy phases do differ in the amount of laser light that
they reflect, the difference is quite a bit less (and the resulting RF
data signal is weaker) than is the case for manufactured/stamped CDs
(strongest signal) and CD-R discs (intermediate). In order to play
CD-RW discs, the "front end" circuitry in the laser/photodiode system
needs an automatic gain control system, so that it can boost the
amplitude of the (weak) RF data signal from a CD-RW, without being
overwhelmed by the stronger signal from a CD-R.

This sort of AGC circuitry is commonplace these days... almost all
CD-ROM drives built within the past five (or more) years have it, as
do a good majority of home audio CD players and car-audio CD players.
Even the little $40 Discman-style player I bought for my wife last
fall has it.

Older CD players often don't have AGC. They'll work with manufactured
CDs, and will often work with high-quality CD-Rs, but will usually not
work with CD-RW discs.

There's another possibility, though. It's possible that your car
system *will* play CD-RW discs, but only if they've been properly
"finalized" or "closed" (the final step in writing a discs, which
writes the Red Book table-of-contents in the leadin area). Some
CD-burning packages won't close the disc until you tell them to do so.

An un-finalized CD-RW may play just fine in the computer's CD-RW
drive, but would not play in most CD-audio players (including car
players).

2) How much more would the unit cost to make if it did


These days, not much at all. I'd guess that the additional bill-of-
materials difference is under a dollar, and may be as small as zero
due to the fact that CD-RW compatibility is widely available and is
built into many of the chipsets.

And

How much more would my KIA CD player cost to make if it advanced and
reversed within a track.


Again, very-little-to-nothing... it's probably just a matter of
programming, rather than the need for any difference in the actual
electronics.

You might want to double-check - your KIA player *may* already have
this capability. My car CD player uses the same pair of buttons for
"track skip" and "track advance". A quick press-and-release jumps to
the beginning of the previous / next track, while a press-and-hold
will advance or replay through the current track.

BTW I thought this unit was broken so I
called the dealer for the replacement cost--$867. He said he was not
kidding.


That probably includes a "book standard" of 2 hours of labor for a
15-minute job to de-install the old radio and install a completely new
one (the old one is probably junked rather than repaired), plus retail
markup, plus the Dealer's Wife Needs A New Lexus fee, plus the Car
Owner Insists On Having Exactly The Same Model And Faceplate On Which
We Have An Exclusive Monopoly tax, plus the Owner Is Too Busy To Shop
Around surcharge, etc.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
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