Earlier this year, we tested 54 2005 HDTV sets to learn how they process all the detail contained within 1080i high-definition signals. The results were disappointing. Slightly less than half of the models tested failed to properly deinterlace a 1080i high-definition signal, resulting in a loss of picture resolution. Thanks to our readers' response to dealers when shopping for high-definition TVs, a number of manufacturers took notice.
In the November 2007 issue, I tested 74 HDTVs for their ability to process 1080i signals, the highest resolution standard found on most of the broadcast and cable networks. A number of the remaining HDTVs to be introduced in 2007 arrived too late for our November issue. We decided to follow up with some more displays. Due to space constraints, this article will refer to previous articles more than we normally do. On the bright side, all the articles mentioned (including the November 2007 test) are available on this site.
The current top HDTV broadcast resolution is 1080i (interlaced). Most television and cable networks use it, including CBS, NBC, the WB, HBO, Showtime, HDNet, The Movie Channel, Starz HDTV, and others. What happens to this HDTV signal when one of the latest digital HDTVs processes it? Does it take the full 1,080 lines of transmitted resolution, change the signal from interlaced to progressive (called deinterlacing), detect and compensate for motion, and send it to the screen, as it should? Or does the display's processor cheat you out of seeing all the detail within the broadcast?
There’s more that goes into making a good display than accurate color, but it’s certainly one of the biggies. Color in a video display may seem like a relatively simple subject, but it’s not. In this Gear Works, I’ll outline the two most important factors in assessing and measuring the color accuracy of the HDTVs we review—color tracking and color gamut. I’ll also show you how we present this in the HT Labs Measures graphics that accompany our reviews. This article will shed some light on what these important measurements tell us about the color accuracy of the displays we test here at Home Theater.
Those of us who’ve spent a lot of time reviewing movies on video discs (from Blu-ray to DVD and, for some of us, even back to Laserdisc) understand that the process involves its share of both objective and subjective criteria. The exact balance varies depending on the content under review. Every movie—and every disc—is unique. Nonetheless, certain rules and standards hold true in most circumstances. While Blu-ray Discs provide vastly better quality than DVDs, and we in turn have gotten a lot savvier over the years in detecting the nuances of what makes a good or bad video image, the fundamental process has remained unchanged in the transition from standard definition to high definition. That is, until now. The introduction of 3D has thrown things for a pretty big loop. The more 3D content I’ve watched (on Blu-ray or other sources), the more questions I have about exactly how 3D should be evaluated. It turns out that reviewing 3D is a lot trickier than reviewing standard 2D.
We often get letters at Home Theater asking about our lab tests for audio products and why we perform them. In the simplist terms, our lab trials serve two key functions. The first is to warn you, the consumer, about any false or misleading claims that manufacturers might make about the performance of their products. The second is to add objective insights to the reviewer’s subjective observations about the sound of a product, and most important, create verifiable criteria on which to compare similar products. Our goal is to provide the most pertinent audio technical information and present the data in a consistent manner over time that allows for easy comparison, even over a wide range of model sizes and prices and over the span of many years. Here’s how we condense a day’s worth of measurement data into a few salient points in what we call the Audio Measurement Box.
In the continuing saga to explain our measurements charts, senior technical editor Mike Wood explores ground control for your home theater: the preamp/processor.
Launching the space shuttle requires the actions of thousands of control systems and hundreds of people all directed by, ultimately, one person. Technicians sit in front of dozens of monitors, checking systems, subsystems, weather patterns, and so on—all to make sure that, when the chief gives the order, the big hunk of steel sitting on the launch pad is able to take off without a glitch. You may not be igniting hundreds of thousands of pounds of rocket fuel when you press play on your DVD-player remote, but you are trying to launch your home theater system, and you usually want it to happen without too many hang-ups. The main component that controls this process is the pre/pro, or preamp/ processor. This is the subject of our latest Boot Camp in the series explaining the technical measurements that accompany our product reviews.
Last month, we explained our speaker measurements. Now, senior technical editor Mike Wood tackles the intricacies of video-display measurements.
It's only fitting that our video measurements be displayed in an obscure, almost-illegible triangle. Three-sided geometric shapes have always been somewhat mysterious objects, implying power or fear. Our measurements can do both. In this, our second attempt to explain to you, our faithful readers, what the ancillary boxes labeled "HT Labs Measures" mean, we'll discuss what our detractors call the triangle of death, why we use it in our display measurements, and what it means to you.
Wondering what those confusing charts in our gear reviews are really telling you about a product? Just ask senior technical editor Mike Wood. This month, he explains speaker measurements.
Unless you're looking at a powered speaker (with built-in amplification), the power-handling rating (which is often incorrectly referred to as the number of watts a speaker has) will tell you little about how the speaker integrates into your system, let alone how it sounds. This isn't to say that the spec is useless. After all, some people like to play music really loud—I'm talking head-near-the-speaker-stack-at-a-rock-concert loud. In those rare cases, this specification may be useful. However, for the rest of us, this is probably the least necessary information, even though it's usually the most common question we get about speakers.
As you can see in the box below, we have completely revamped our video-measurements box. Gone are the plain, boring, and hard-to-understand Excel-based charts. In their place are shiny, easy-to-understand, colorful graphs. Yep, party like it’s 1994.
In an ongoing effort to present the most comprehensive and accurate measurements possible, we’re revamping our video measurements and adding new test gear. In this first installment, I’ll look at the new gear. Next month, I’ll dive into a whole new measurement box, with several new measurements.
To test your display's performance, you'll need not only specialized test generators and measurement devices, but also actual video material. After all, just because a display measures well doesn't mean it's anything you want to look at. For that matter, there are no objective measurements for things like scaling and deinterlacing. For consistency, we try to use the same or similar test DVDs (and now HD DVDs) for our testing in each display review and in our video Face Offs. If you want to see how your TV stacks up—or you wonder what we're talking about every month—here are most of the test discs we use and why we use them.
THX is setting a new standard for picture quality and making shopping for HDTVs easier.
When you think of THX, you think of great sound, right? Those three letters have been synonymous with cinema and home audio for more than two decades. So, when THX launched a new certification program for high-definition video products at last year's CEDIA and helped introduce several new THX-certified projectors from Runco and Vidikron, it raised a few eyebrows in the consumer electronics community.
I'm sure many of you read over the measurement boxes in our video reviews, take what you need from them, and move on. But what does it all mean, really? Why do we do it the way we do? For those of you new to the magazine or video displays in general, what does any of it mean? These are excellent questions.