Letters to the Editor - July 2002
Progressive-scan DVD
July 24, 2002
To Wes Marshall,
I recently read your
review of the NAD T571 DVD changer, and I wonder if you could answer a couple of
questions for me. In my research of DVD players, I see that most new ones feature a
10-bit/54MHz D/A converter for the video. However, Sony's new players have a 12-bit/108MHz
converter. Not being a techie, does this mean the Sony should produce a better picture
than the NAD? Are these converters just for the progressive-scan picture? I want a DVD
player that has excellent sound quality for CD as well as a good picture. Sony's new
changer sells for only $249. I assume that the mass-market Sony does not use
audiophile-quality parts as does the NAD, but I'm wondering if there's really that big a
difference in sound quality.
In regard to the video, Cambridge Audio makes a DVD player
without progressive scan. They claim that you get a better picture with less artifacts by
using the component output with a TV with its own line doubler. They claim feeding a
progressive-scan image into a TV with its own line doubler is not a good thing. Any
opinion on this? Any help you can provide is greatly appreciated. I find a lot of this
quite confusing. Thank you.
Walt Bromby
The answers to all your questions depend on your
equipment. The 12-bit/108MHz converter, in theory, gives the DVD player greater control
over the luminance and color. If you have been following the development of DACs over the
years, you'll remember that increased bits or speed have not always been a direct line to
improvement. A lot will depend on the implementation. Sony puts out some wonderful stuff,
but I think NAD, in general, will be a bigger stickler for proper implementation.
One of my concerns about the Sony implementation actually
answers another of your questions. Sony goes into great detail about why their progressive
scan is better than anyone else's. If you check their website, they show a blurry picture
and say it's interlaced and a sharp picture that is progressive. Does that mean their
non-progressive players are blurry?
The truth is, it all depends on what you're watching. If
your display has high-quality processing, DCDi for instance, I would prefer to let the
display do the processing rather than the DVD player. If you had an older
presentation-type LCD projector, then yes, the Sony might look better. Might. If you have
something with good processing on board, maybe not.
I just finished an extensive review of the Boxlight Studio
Experience 12SF. That projector has the DCDi chipset from Faroudja. The best picture I got
was using the NAD's component outs set for interlaced into the 12SF. This allowed the DCDi
to convert the signal to progressive. My guess is that Cambridge is probably assuming a
high-quality display with good internal processing. That would make the issue of
progressive scan in a DVD player moot.
One of the worst pieces of equipment I've ever owned is the
Pioneer 434, one of the first progressive-scan players under $1000. Yes, it had
progressive scan, but no 32 pulldown. The result was a mess. But it had those magic words
"progressive scan." If I put a supercharged 454 engine in a Corolla, the wheels
will spin and the first corner I hit will give new meaning to understeer. Implementation
is the key to everything.
Finally, regarding sound quality, I can only point you to
my review. The Sony you are looking at, the C655P, lacks HDCD decoding, a potential issue
if you have many HDCD CDs.
Most of the mass marketers will allow you a free return in
under 30 days, and most NAD dealers will allow you to take a demo home for a night or two.
Why not do your own review and check for yourself?...Wes Marshall
Meridian
July 23, 2002
Editor,
Whilst we are still slightly behind on the home-theater
side of things, the UK still builds some great equipment. Take, for example, the Meridian
861 processor. I wondered if anyone has published a review comparing the best
surround-sound processors -- to my ears the best processor is the 861. I have compared
against a Theta Casablanca II with all the bells and whistles, barring the new extreme
DACs. I managed to do this comparison by covert means, as in the UK it seems that the two
are always exclusive of each other. It would be interesting to hear what the views of
yourself and your team are.
Will Loyal
While I have not heard the big Meridian in my system, I
have heard it extensively in a system of high pedigree. You're right -- it's a fantastic
piece of gear, likely one of the best available. It also has some flexibility with the new
DVD-Audio format that no one else has managed to match. I'd like to hear it at home.
Perhaps we can talk with Bob Stuart and arrange a review....Jeff Fritz
Piega speakers
July 22, 2002
Editor,
I found your
review of the Piega speaker system especially useful. I'm considering that very system
for my apartment, and your review told me basically everything I needed to know. I'm sold
on the speakers, but I am worried that I'll have to send them back to Switzerland if
service is ever required. Do you know if that is the case?
Robert Folger
The North American importer, Steve Davis of Sanibel
Sound, is prepared to provide service here in the US and Canada. I would not suspect that
replacing a driver would be a problem should the need arise. I'd feel confident that
service would not be an issue....Jeff Fritz
Mixing and matching
July 16, 2002
Editor,
I have planned to buy the following components for my
home-theater system. Can you please guide me and tell me if these products would do well
together?
Amplifier: Denon AVR-1602
DVD player: Sansui DV2000
Speakers: Definitive Technology PRO 80
Thanks and regards,
Tome Desouza
In most instances, modern-day home-theater equipment is
surprisingly easy to match. Most receivers will work with most DVD players, for instance.
The trick usually comes when you're matching speakers from different manufacturers. This
can be tricky, and it's why we typically recommend that folks buy all their speakers from
the same maker. Let the manufacturer do the work! The other consideration when mixing gear
is control. It's not really an issue with learning remotes, but many prefer a standard
system remote designed to work with components from a single manufacturer.
Beyond those issues, I don't see any problem with what
you have chosen and would expect it to work fine....Jeff Fritz
Center-channel height
July 10, 2002
To Roger Kanno
I read your very interesting article on
speaker placement. Great work!
I need a suggestion before I buy an entertainment center
I'm looking at. I like it very much, but I am concerned about its height. It is six feet
tall. For my unipolar center-channel speaker, would it be too high if I place it on the
top of this entertainment center? I might also buy a Mirage Omnipolar center-channel very
soon. How would this six-foot entertainment center fit? I will be about nine feet from the
entertainment center. Please advise. Thanks.
Kiran
Yes, six feet does sound a little high for a
center-channel speaker, but it also depends on how high your left and right speakers are.
What you want to avoid is having the tweeters of these speakers being at drastically
different heights, which will make the sound seem like it is coming from different
positions instead of from a continuous left-to-right soundfield. Having all three front
speakers a little high or a little low is better than having the center-channel a lot
higher or a lot lower than the mains.
The Omnipolar center-channel may not work out too well if
it is placed in an enclosed or semi-enclosed entertainment center. Omnipolars radiate
sound forward and backward, so if the speaker is placed in a unit with sides and a back,
the sound will not be able to radiate properly from the rear drivers. Height should not be
any more of a problem for Omnipolars than any other type of loudspeaker....Roger Kanno
Transzorbs explained
July 4, 2002
To Doug Schneider,
I read your review of the PS Audio Ultimate Outlet, and I noticed that you
mentioned the use of Transzorbs as the device of choice for surge protection, and that you
hadn't heard of them before.
I am currently working in commercial communications for
Nortel Networks, but I used to be in aerospace. I worked as an electromagnetic
interference/compatibility engineer on a lot of programs for Lockheed-Martin. My degree is
in physics with a specialty in electromagnetic theory. Our group was also responsible for
electromagnetic pulse/lightning protection/electrostatic-discharge-effects protection on
programs. I worked there from 1986 to 1993.
In short, Transzorbs, as you mentioned, are a proprietary
surge protector made by General Semiconductor. The typical devices we used for surge
protection were gas-filled discharge tubes, MOVs, and Transzorbs. The general
characteristics in using these devices in a design were:
Gas-filled discharge tubes: very high current/energy
handling, but slow reaction/clamping time, fairly expensive devices;
MOVs: significantly faster reaction/clamping time than GFDT
above, but not as much current/energy handling capacity, very cheap.
Transzorbs: by far the fastest reaction/clamping time,
current/energy handling comparable to MOVs, a little more expensive than MOVs.
In an electronic design, multiple MOVs/Transzorbs can be
used in parallel to obtain increased current/energy handling. In any real quality design,
however, we never used MOVs and always used Transzorbs; we never used gas-filled discharge
tubes except in the most extreme cases. The bottom line was that Transzorbs were the best
semiconductor device available. Ever since I worked at Lockheed-Martin, I consider any
surge-protection device that uses MOVs as its primary protective device as a marginal
product. Old technology, but cheap.
I'm surprised it took so long for someone in the commercial
world to pick up on Transzorbs. They've actually been around for a long time.
Charlie Martin |
