Q&A # 20 - July 16, 1997
Staff
Q I recently purchased a good home theater system and began collecting old movies from the 60s. I noticed that a lot of them have a blue cast to them. I understand that the colors in the film have faded, but why don't all the colors fade the same amount?
A This has to do with the dye sensitivity. When the original three-strip Technicolor process was used, the image was gathered on three separate black and white camera negatives, each exposed through a different color filter. The release print was made using a dye transfer process, and color adjustments could be made. Even with really old three-strip Technicolor negatives, such as the Errol Flynn version of Robin Hood, the black and white negatives faded equally, so pretty accurate color restorations could be done from the negatives. When three-strip Technicolor became too expensive, color was shot on color film, producing one strip of negatives. The release prints have dyes which are sensitive to continued light exposure, and the red dyes absorb the blue light (and any ultraviolet) portion of the white projection light which has a higher energy than the red light being absorbed by the blue dyes. This light energy bleaches the dyes. So, over time, the release print has faded reds, leaving blues not so bleached, giving the blue cast. The films you bought were probably made from an old release print rather than from the original camera negative, because it is less expensive to do it this way.
Q I have a Harmon Kardon AVR-80 and a Panasonic DVD player. I have spent the last two nights trying to tape a DVD. Is there something to prevent it? I am very confused over input and output screens with the on-screen menu. It
seems that I can't get the VCR and the DVD player to communicate through the receiver.
A DVD has two forms of copy protection (Macrovision). You might be able to
copy a couple of titles, but most will not copy due to the protection. What
you will usually see when trying to copy a protected disc, is the picture
level changing from dark to light over and over again, making the image impossible to view properly. The brightness is changing, but the color is staying the same,
giving you a really unwatchable picture.
Q As a result of your advice I am now interested in a DVD player (Toshiba 3006). However, on a visit to an electronic shop (in Mexico City), the dealer told me that I need to buy the DVD player here in Mexico, because
they are configured in a different way in various parts of the world to read the
software, and if I buy the DVD player in the USA, I could not play either the
local Blockbuster's software (rental DVD videos) or play any DVDs purchased from my
local store. If this is true, I should not buy either the DVD player or
software in USA. I do not believe this, because many electronic components and software come from the USA to Mexico. What is the answer to this problem?
A Sad but true. The US and Canada are in Region 1 while Mexico is in Region
4. You will have to buy a player in Mexico if you want to watch movies
released in the area or rent from your local Blockbuster video. If you
wanted to watch films released in the US then you would have to purchase a
US player also. Not all DVDs will encoded with a Region ID, but most are
planned to be that way.
Q I was scanning through the Q&A #19 page, and after reading the answers to questions 1 & 2, became really confused. In the first answer, you said that Dolbly Digital and DTS both will play through the DVD's digital port to the
receivers digital port no problem. But, then, in the answer to question # 2,
you stated if you wanted to use DTS, you had to use the 5.1 jacks. What is
the right answer? I am getting ready to purchase the new Yamaha RX-V992
receiver this week and the new receiver does not have the 5.1 jacks any
more. Am I cutting myself out of the future?
A AC-3 and DTS are both digital bitstreams. They will play to the
digital port of a receiver, as long as the receiver has AC-3 and DTS
decoders built in. If the receiver has only AC-3 capability, then you
have to connect the digital out from a laserdisc player or CD player
or DVD player to the DTS decoder first. The analog outputs of the DTS
decoder have to be connected to a set of 5.1 inputs (RCA jacks) on the receiver.
This can be done with the Yamaha RX-V990, which has the set of 5.1
input jacks, but not on the RX-V992, which does not have a set of 5.1
input jacks. The 992 has AC-3 decoding built-in, but you would not be
able to use DTS with that receiver, unless you had someone like MSB
Technology (http://www.msbtech.com) put a DTS decoder board into the receiver. That would cost
about $700, which is roughly the cost of an outboard DTS decoder
anyway. The 990/992 series is one of the best receiver series Yamaha has
built (IMHO).
Q How long do I hang onto an older but adequate Processor? I have a Yamaha DSP A-1000, and I use External Amps thanks to the Yamaha's
Pre-out options. Is is feasible to utilize outboard AC-3 processors,
RF-demodulators, even DTS boxes..if & when....or is the wiser choice to just
move on and up to a New unit? And is separating RF from the Digital really
Critical, i.e., multiple boxes?
A You could probably have someone put in an AC-3 board and a DTS board to your existing receiver, but it would cost over $1,000. I would suggest retiring your A-1000 to the kitchen, and getting a new receiver with 5.1 input jacks and AC-3 built-in, or one with just the set of 5.1 input jacks (as well as pre-outs for a good five-channel power amplifier). Multiple boxes give you a a great deal of flexibility, in that you can use a combination of receiver, AC-3 decoder, and DTS decoder brands. The price is higher, and you need to have the knack for connecting lots of cables. Separating the RF from the digital decoding is not critical, but I have always felt it is best to keep the RF away from the preamplifier section of the receiver, so I use an outboard AC-3 RF demodulator/decoder.
Q I work in a audio-video store that does a lot of business in mid-fi audio. My question concerns the use of 4 ohm speakers with an AC-3
system. Specifically, I am referring to the use of of Kef Reference
threes up front, Twos in the rear and a 200C center. Would Adcom 5500
and 5300 amps have enough headroom to drive them well in AC-3? Would
the 7000 amp do well? I have a customer that is looking at said system, and
I want to make sure that she is getting something that would sound great and
justify the expense.
A Using 4 Ohm speakers is stressful to most amplifiers. MOSFET output devices are known for their musicality rather than their high current output capabilities. The 5500 puts out 200 watts per channel (two channel amplifier), while the 5300 delivers 80 watts per channel (two channel amplifier). AC-3 requires lots of power, if you really want to experience it right. The GFA-7000 uses bipolar output devices, which are good for high current, but it can clip with 4 Ohm speakers when the signal is high. I would suggest the 5503 (three channel amplifier with MOSFET output devices) for the front left/center/right, and the 5500 (also uses MOSFET output devices) for the rear. This will give your customer 200 watts per channel for all five channels. We used this particular combination with AC-3, and they were great. P.S. Don't forget the subwoofer!
Q In your Q&A #19, you claimed that DTS would work with first generation DVD players. DTS themselves, doesn't seem to be so certain. On June
20th, Karen from DTS wrote the following in alt.home-theatre.misc:
"Hello, Yes, DVD discs must contain Dolby Digital, but it can also
contain DTS. We are an approved alternate format for DVD. I know there has
been confusion if the first generation DVD players will work with DTS or
not. Engineering is working on that now and the final answer hasn't been
determined. I know last week the answer was no, we wouldn't work with the
first generation. But, that may change. I know this is frustrating, but,
please stay tuned. I'll post once I get the word. Thanks for the patience.
Karen at DTS"
A Thanks for the clarification. DTS CDs do work with the DVD players, as we mentioned, but it is apparent that DTS is still working on the capability for DVDs with DTS soundtracks to be played on the first generation of DVD players. I would imagine this is a top priority for DTS. I'm certainly not ready to ditch my brand new DVD player for another one so soon. Probably just about all of you feel the same way. I assume DTS understands this. On the other hand, I am very pleased with having a DVD player now, because the video quality is superb. If the S-Video connection is used rather than composite, DVD is much better than laserdisc (better color saturation, no dot crawl, better resolution). Component video connections are even better, but only a few DVD players and TVs have the outputs and inputs for this.
� Copyright 1997
Secrets of Home Theater & High Fidelity
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