|The Digital TV Buyer's Guide|
“What do you mean a plasma TV needs to be recharged?” I asked a dim-witted salesperson at the local electronics warehouse. He stumbled, admitting that he didn’t know, which wasn’t surprising, particularly since it’s a complete lie. I walked out, mildly disgusted, but mostly amused that retail stores could expect to sell anything at all with such minimal training of their staff. It was only the first store I’d visited on my quest to buy a new TV and I quickly realized it would take dozens more for me to figure out which TV to buy. That was when Editor Mike Wood suggested I log my travels, so that others might shorten their journey when shopping for a big-screen TV.
I was looking to replace my old big-screen TV, which had finally faded away enough to justify giving it to my son to use for his video games, in turn so I could buy a new TV. My son didn’t seem to mind the almost 3-D-like image, as the TV’s internal red, green, and blue tubes had drifted apart from each other. These are some of the shortcomings of cathode-ray tube, or CRT, technology. Sure, I could hire a tech to reconverge the colors, but that costs money, and while the picture was good in its day, it was time for something new. Even though the few remaining models of CRT-based TVs don’t cost a lot and the picture looks good from most of them, my wife always hated the huge cabinet. Promising her something slimmer helped support my cause to get something that would support high-definition signals.
Acronym Soup Walking into our first retail store, my wife pointed to a plasma TV and said, “I want one of those.” At least, I think it was a plasma TV. It was flat and hung on a wall, but could have been an LCD. Both technologies can be used in flat displays. While large screen (50-inches or larger) flat-panel sets are coming down in price, look good, and support high definition, they never seem to offer all three at the same time. After an extensive search, we decided that we didn’t want to break the bank or compromise simply for aesthetic reasons, so we looked at what Carlos, one of the more knowledgeable salespeople at the local A/V hut, called digital rear-projection TVs (digital RPTVs).
This group, he exclaimed, includes large-screen TVs that are based on technologies like liquid crystal display (LCD), digital light processing (DLP), or liquid crystal on silicon (LCoS—this is also referred to as HD-ILA in JVC products and SXRD in Sony displays). Screen sizes range from 45 inches on up, and cabinet depths are half of that of our old TV. If you can accommodate the depth, we found you could get a lot more for your money than with a budget-priced plasma.
A couple salespeople described these as
“microdisplays.” The moniker seemed more than a bit outrageous given the large
screen sizes, but the part of the TV that generates the actual picture is about
the size of your thumbnail and is broken down into a grid of even
smaller elements called pixels.
An industrial-grade lightbulb illuminates the image and will eventually need to
be replaced. Longevity varies, with bulbs lasting 2,000 to 4,000 hours and
costing a few to several hundred dollars to replace. We had to decide what
technology we wanted first, though––as there are a few advantages and drawbacks
to each–– before looking into other features. Most of the salespeople I spoke to
could hardly describe the differences, let alone how each technology worked.
Fortunately, you don’t really need to know either, and can just look at the
LCD displays, for example, are the least expensive type of digital RPTV. The models I saw also seem to have more natural colors than other technologies, though none of the salespeople could explain why. The dots that make up the picture in an LCD TV are slightly more noticeable than with other technologies, which makes it look like you’re watching the image through a screen door. Black portions of the image also don’t get as dark as they do on DLP or CRT-based TVs, which makes shadows easier to see in bright rooms, but flattens or washes out the image in a dark room.
DLP technology, on the other hand, creates darker blacks than LCDs and has a similarly bright image, creating excellent contrast or depth to the image no matter what the room lighting. The DLP’s pixel structure is also more closely packed together than an LCD’s, rendering it nearly invisible. DLP TVs use color filter wheels to create the color in the image. This process can create rainbowlike trails of colors behind moving objects for a small percentage of viewers. It didn’t for me, but then color accuracy on less expensive DLP televisions didn’t seem as good to me as from LCD TVs. Some expensive DLPs, like RCA’s 7-inch deep model, looked outstanding.
Last but not least there’s LCoS. The salespeople were the least knowledgeable and most skeptical of LCoS technology, despite some of the great pictures I saw. My go-to guy, Carlos, explained that numerous manufacturers—including chip giant Intel—have tried and failed to make LCoS work economically, pulling products from the market as quickly as they introduce them. Others, such as Sony and JVC, have been more successful. LCoS is an advanced form of LCD that is similar in quality to DLP.
Having picked out a
few selections that fit our living room’s typical light levels, and numb from
all the technical explanations, we changed the direction of our search to focus
on some of the features found on current TVs. When I bought our last TV, the
only thing I had to worry about was if there were enough inputs on back to
accommodate our VCR and cable box. Now there are a few more things to consider.
Resolution (SD, ED, and HD) Fortunately, we didn’t have to worry about the resolution difference between what are known as standard-definition (SD), enhanced-definition (ED), or high-definition (HD) compatible TVs as nearly all digital RPTVs fall into the latter group.
There’s just no other choice. Some are theoretically more HD-capable than others, though. Most HD displays have a 720 line vertical resolution, which relates to the number of horizontal lines or rows of pixels—measured vertically—used to create the image, and this resolution corresponds to the same high-definition signal resolution broadcast by networks like ABC and Fox. But CBS, NBC, and many satellite and cable channels use a different high-definition signal called 1080i. When these signals are played back on a 720p display [and all processing issues aside—please see the 1080p feature on page 36], the TV only uses 720 of the 1080 pixels. Even when these signals lose a third of their vertical resolution, they still have enough left to be considered high definition and look great, but some new TVs are 1080p-capable and can play the full 1080 line signal. These sets are more expensive, though.
In most cases, I couldn’t tell the difference between the two. My ophthalmologist pointed out that the human eye could only resolve so much information. If you sit more than one and a half times the picture size (measured diagonally) away from the screen, your eye may not be able to see the difference between TVs with 720 and 1080 resolutions. Carlos effectively demonstrated a lack of image distortions and artifacts on a 1080p TV, but it was a subtle difference.
Integrated Televisions versus Monitors The resolution advantage of any high-definition television is lost if you don’t actually feed the TV a high-definition signal. For this you need a rooftop antenna, digital cable or satellite signal, and even then, only certain channels are available in high definition. Carlos turned me onto antennaweb.org and titantv.com, websites that can help you determine what HD signals you can get. We have digital cable, but the cable company only offers a couple of HD channels. Fortunately, here in Springfield, Mass., there are a few local broadcasters that transmit HD signals over the air, as well. I decided to reconnect our home’s dormant and neglected rooftop antenna so that we could receive the local signals.
salespeople seemed eager to sell us an integrated HDTV, pointing out that we’d
need the built-in HD tuner to receive and decode the off-air HD signals that
would come from my antenna. Integrated sets cost a couple hundred bucks more
than what are called monitors—sets that have the resolution to display HD
signals, but lack the internal tuner. Manufacturer terms for these sets range
from “HD-upgradeable” to “HD-compatible” but they all mean the same thing. If
you have cable or satellite, you probably already have a separate tuner and an
HD monitor is fine.
The integrated tuner’s added cost (and resulting commission) may have sparked the salespeople’s enthusiasm, but the built-in hard drive, or digital video recorder that many of these TVs include sparked mine. The DVR can record TV shows like a VCR but has many other advantages, too, like constantly recording live TV so that you can press pause when the phone rings.
Many integrated sets are also digital cable ready. I could get a CableCard from the cable company, plug the card and the cable line into the TV, and be rid of my cable box altogether. A quick call to my cable company, however, suggested that all would not be so ducky. The digital-cable-ready TVs don’t use the cable company’s on-screen channel guide, can’t access video on demand, and don’t always have dual tuners. This seemed somewhat useless. By law, the cable company is required to provide cards when asked, but the customer service rep mentioned that some TVs have problems accepting an area’s given CableCard—a fact I confirmed with a few neighbors. The cable company’s external dual-tuner, HD-DVR cable box has none of the same drawbacks as CableCard, but does cost a bit more per month.
If the cable company offered more local HD channels, all would be good. But mine doesn’t and its HD-DVR cable box wouldn’t decode off-air signals, which meant I’d still have to get an integrated TV and change inputs for cable versus off-air channels. I could just wait until more local channels were available on cable, but I hate waiting. Frustrated, I cancelled my cable service and signed up for Dish Network’s satellite service, instead. Their PVR-942 receiver not only includes an HD-DVR, but decodes off-air signals, too. The savings on the HD-monitor would offset the cost of the receiver somewhat, but the system would be simpler and my monthly bill would be lower.
Connections The only thing left to consider was the television’s
back-panel connections. Carlos suggested purchasing a TV with more connections
than I had components for. Since I route many signals through my audio/video
receiver, we could get by with fewer inputs. He helped me map out a connection
plan, which covered most of the basics.