Constructing a home theater can be quite a daunting task. It entails such weighty decisions as choosing a particular home theater design, deciding on a home theater projector, plasma or LCD flat screen TV, and purchasing a surround sound system. The two most important aspects when considering your home theater installation are the picture and sound. If you are currently contemplating the decision to purchase a television, such as plasma or LCD flat screen TV, or a projector for your new home theater design, you should consider the pros and cons of each before making a final decision.

Both a plasma and LCD flat screen television are similar to the screen on your laptop computer. They both have wonderful picture quality. However, the level and crispness of blacks and whites are not the greatest. LCD TVs are limited in size, where you would be able to obtain a larger picture with both plasma and projection TVs. Available flat panel models vary greatly in size. You have sizes that range from handheld up to 84”. The average size falls within the 20-42” inch range with the most common sizes being 26”, 32” and 42”. Most, if not all models that are smaller than 42” are LCD flat screen TVs. On the low end of estimates, you can expect to pay approximately $1000 for a 32” model, between $1500 to $2000 for a 42” model and well over $2000 for models 50” and over.

The width of plasma and LCD flat screen TVs make it easy for them to be mounted on a wall or even over your fireplace mantel. They are also easy to move from room to room without much effort. One advantage of using a LCD flat screen TV in home theater design is it enables the home to combine its television activities with its online, computer activities. LCD flat screen televisions are specifically designed to provide computer interactivity while doubling as a television.

If you want to capture the true feel of a cinematic experience, purchasing a home theater projector would be best for your home theater design. One important consideration when deciding on a projector in your home theater is ambient light. If you are choosing to install your home theater in a room with a lot of windows it can cause problems, as the light would degrade the image on the screen. The ideal location for a home theater when using a home theater projector is one where you can control the lighting. This can be accomplished by the use of blackout curtains or having your home theater in a room where there are no windows such as a basement or interior room.

One particular advantage of a home theater projector is the size of the screen. Projectors can produce images of 81” or larger. This is not possible with plasma or LCD flat screen televisions. However, your home theater would have to be fairly spacious to project such a large image from the projector to the screen.

In addition to the projector, it is necessary to purchase a screen. The quality of the image is dependent not only on the quality of the projector, but also the surface onto which the image is projected. A quality high definition projector would be wasted if the image were to be projected on an inexpensive $20 screen or on a wall. An equally high quality screen that has a matte finish to diminish both glare and reflection would be optimal.

If you have the space and the appropriate lighting scenario, a home theater projector is the best option for a true visual cinematic experience.

            When an argument such as this is split down the middle, it can be difficult to make heads or tails of, especially when blind opinion looks quite a bit like its older, wiser cousin fact. Experience tells us that juries are usually hung for a reason: sometimes, there just isn’t a black and white answer to the question at hand. If you ask the wise, temperate video expert for his two cents on the subject, its very likely that he’ll say, “Which is better? Well, I know you don’t want to hear this, but that all depends.”

            If you want to know whether HDMI or component cable is better, you’ll have to look to a variety of factors, foremost of which are the source and output devices — the television and DVD, say — of the signal you’re transmitting. There may be some differences between the image quality transmitted by an HDMI and an analog component cable, but the nature of these differences are not inherent in the cable type and will depend on your television and DVD player.

            The HDMI and component cables themselves are actually very similar in design and function. Both HDMI and component cables split data being transferred into 3 color component parts: red, blue, and yellow. The fundamental difference between the two is the form of the data they transfer. HDMI cables deliver the data signal digitally, while component cables deliver the data in analog. That is, component cables send the signal as a series of voltages, rather than a digital bitstream.

            Followers of HDMI assert that component cables suffer data loss — thus delivering a poorer image — because they must convert digital data from your DVD into analog before they send it to your HD television, where the data is converted back to digital. While this is arguable, many experts are willing to admit that in many cases the data loss could be negligible. Additionally, the distance component cables will run in the typical home is probably not enough to give one reason to expect that there would be any loss at all.

            Supporters of HDMI are quick to argue that HMDI cables deliver digital data from a DVD to a digitally capable television without ever converting the data to analog. What is left out of this equation is the fact that high-definition televisions have a native resolution — say, 1080i — and that the television usually must up-scale or downscale, depending on the resolution of the data being conveyed. This process can also degrade the picture quality on your television, but the degradation is — as with component cables — likely to be negligible. It is also heavily dependant on the DVD player you use, the television you watch, and the data running through your cables. There is no way to guarantee that digital-to-digital transfer will result in better signal quality.

            Many experts argue that though component cables are quite robust — and have great control over impedance — HDMI cables suffer when run over significant distances. Up to a certain length, the HDMI cable will transfer the signal without problem. But due to poor control over impedance, a signal run through a long HMDI cable may bounce off the display end of the cable, resulting in interference of the signal. When the length is too great, the television will fail to render an image.

            There just isn’t any easy way to predict the results you’ll have with HDMI or component cables. As high-definition technologies evolve and the options become more varied, some video enthusiasts choose one cable over the other for an obscure, sometimes simple reason. Some choose HDMI because component cannot transfer 1280p signals or because HDMI cables are so easy to connect. Others choose component because the cables come with the television they purchase. If you still have a difficult cable choice to make, the best thing you can do is to forget what you’ve heard, get out there and experiment.

It is important to understand how interlacing works, and what it is. It is, essentially, just as its name implies. It is a video image made up of interlaced lines. Motion pictures are not truly in motion, but instead are made up of many still images flashed quickly to give the illusion of movement. These images are flashed at a rate of 24 frames per second (fps). When looking at interlaced video the idea of frames per second is replaced with fields per second. Each field is made up of lines drawn on the CRT face from left to right and top to bottom. The fields are alternated, odd and even. To get the whole picture the fields must be interlaced. This gives 60 unique fields per second.

When the image is still, the alternating fields complement each other and the resultant image is clear, although some flicker and scan lines may be seen. Since most video consists of movement, interlace artifact becomes an issue. “Combing” (or “feathering“) and “line twitter” are two common artifacts that effect image quality in interlaced signals.

As stated, when an image is still the two fields interlace nicely and the image appears smooth. However, when the image is in motion the object in the field will be in a slightly different position so the images will not complement each other. This leads to some “bleeding” of the image and since the two fields are alternating odd and even lines the edges will appear jagged. When looking at a smaller display or when further back from the image this artifact, along with others, is less noticeable. Increased bit rate decreases this artifact as well. To get a clearer picture of this, get up close to an interlaced television and watch the edges of objects in motion.

Line twitter comes into effect with finer lines and images with greater detail. If a fine detail appears only in the even lines, when the odd lines are alternated the detail will disappear. So half the time it will be there and the other half it will not. It will “twitter” in an out. This artifact can be present even in still images. Due to this artifact many finer details are filtered out before encoded for delivery by an interlaced device.

Now, going back to the motion picture. It is shot in 24 fps. It is difficult to get a nice even 60 fields from 24 frames, since 24 doesn’t go nice and neatly into 60. To do this a little math is required. Breaking this down to its simplest numbers we see that 4 frames must be made into 10 fields. To do this a “3-2 pull down” is used. Simply put, three fields are created from the first frame and then two from the second, three from the third and finally two from the fourth. The drawback to this is that the artifacts mentioned above are a part of these images as well. When a field is made from a different frame, where movement has occurred, the potential for “combing” and “line twitter” exists.

So, how does progressive scan deal with these issues? Progressive scan takes a “scan” of the CRT after the lines have been interlaced. Instead of showing 60 alternating half fields, the progressive scan shows 60 complete fields, or frames, per second. This eliminates the flicker associated with interlaced pictures. It also makes the scan lines less visible and helps eliminate the other artifacts associated with interlaced signals.

Since truly progressive devices are difficult to come by, the video from many sources must be deinterlaced to be shown as a progressive scan. This involves coupling two interlaced fields to create one progressive frame. This would reduce the overall number of frames, but since progressive scan devices still operate at 60 frames per second they must get back to the same rate as the interlaced. This is accomplished by alternately doubling and tripling the frames and showing them for 1/30^th and 1/20^th of a second. This unfortunately does lead to some “judder”, or hitching, in the playback.

The actual quality of the picture from a progressive scan device will depend on the deinterlacing chip. Due to limitations in digital video equipment, very few videos, television shows, and other media are produced in progressive format, so some deinterlacing is required.

Progressive signals can eliminate some of the flicker, scan lines, and artifact associated with interlaced signals. Currently, it must rely on deinterlacing to do this. As more devices are produced to record and copy in progressive format this will eliminate the need for much of the deinterlacing, and lead to truly progressive scans.

HDMI is the Digital Rights Management (DRM) answer to the common analog standards of coaxial cable, S-video, component video, composite video and SCART.  It also covers the digital standard of Digital Video Interface (DVI.)  The versatility, ability to handle many different formats, makes the High Definition Multimedia Interface attractive to high end video users.  It can handle any TV or PC video input, including high definition video.  Since MPEG movie data streams are passed off to a decoder in HDMI, it is independent of the standards that limit DVI.  This data is encoded into Transition Minimized Differential Signaling (TMDS) and then transmits it digitally over the HDMI.

HDMI also supports 8-channel uncompressed digital audio.  It is backward-compatible with DVI that is commonly found on computer monitors and graphics cards.  As the technology continues to grow the bandwidth sample rates will increase as well.

So, if HDMI supports all of these formats then everything must be perfect, right?  Not quite.  Because HDMI is a DRM technology the sending and receiveing units must be connected by the recognized HDMI.  When switching from one source to another with a direct connection the change must be made manually.  The cable handling the data must be changed in order to deliver the information. 

Most modern HDTVs can handle a direct HDMI connection from a DVD.  To switch to another input, such as a laptop, or audio inputs, the cable input must be changed.  This might require changing the cable or, with the old switching units, manually flipping a switch on the reciever.  This requires getting up off the couch and making the switch.  In today’s world of convenience and automatic switching recievers nobody wants the hassle. 

An automatic switching reciever with multiple ports for incoming HDMI and one output (to an HDTV or projector) allows various sources to be plugged in and, using a remote, switched back and forth without every leaving the couch.  The need for manually switching between components is eliminated.  As the technology moves forward the switching has become truly automatic and switching occurs at the reciever without the need for user input, such as when one component is turned on or off.  Convenience is a major benefit of switching at the reciever.

When a direct connection between the DVD and TV is in place the other components are limited.  The one HDMI port on the television is used up and other feeds are no longer available.  Cable with high definition feeds can not be plugged in.  The limitations make that HDTV very one dimensional in its uses.  A reciever with multiple inputs also allows components with different formats to feed through to the reciever and on to the TV or projector.  Audio, video, computer, and gaming consoles can all be plugged in to a reciever and sent to the receiving unit through the single output.  This eliminates the need for plugging in and unplugging components as they are needed, or manually switching between input sources.  This also reduces the number of remote controls needed.  One remote can control and switch between the various components.

The bacward-compatible nature also allows the HDMI and DVI inputs and outputs to work together without having to make a switch.  Since DVI can manage an HDMI monitor, without the audio and remote control features, this source could could allow for multiple feeds into the HDTV or computer monitor, even with DVI inputs.  The HDMI can control the DVI reciever as well.  If the receiving unit (televisions or computer monitor) has a DVI input and the sending units are HDMI, the reciever can act as an adapter.  This changing of formats does require some adapters and appropriate matches on each end but can be accomplished with switching at the reciever.  Direct connections would not be available. 

Convenience, not having to get off the couch, when switching is one of the major benefits associated with HDMI switching at a reciever, when compared to direct connections between the sources and TV.  The ability to connect multiple input sources, possibly of different formats, is another benefit.  When looking at various recievers the real question is not whether it is needed, but how many ports for input are needed.

But what are the details of this war being played out in labs, corporate offices, and the living rooms and dens of the curious few who have ventured to take a chance and buy a technology that may soon be obsolete? What are the differences between the competing technologies, and which of these differences will slowly lead one product to utterly dominate the home entertainment market?

It isn’t as though we haven’t seen this type of situation before. For those who stayed current with the technology trends in the 80’s, who had the best cassette player with the newest Marky Mark or George Michael tape spinning round and round in the deck, this scenario is disconcertingly familiar. Back then, Beta and VHS vied bitterly for the greatest chunk of the consumer market, and VHS surprised many by winning out, though it was technically the inferior technology. What consumers and experts learned from the 80’s was that “better” is in the eye of the beholder. While Beta had an image quality that was vastly superior to VHS, VHS was capable of containing a greater volume of data content, thus securing it a spot as the more attractive choice to corporate movie studios and consumers alike.

This example from two decades past carries with it some themes that are not so different to the competition we see playing out between Blu-ray and HD-DVD. Blu-ray wins undisputedly in the data capacity category. Because Blu-ray uses a narrower track pitch (the single thread of data that winds around from the inside out across the disc surface), its discs are able to hold more content. Supporters of Blu-ray have boasted of its double-layer disc’s capability of holding 50 gigabytes of content. The HD-DVD disc holds 15 gigabytes at most. Some consumers worry that the lesser data capacity of the HD-DVD would limit what movies could be released for this technology. Experts say a three-hour movie could easily exceed this size.

From the issue of disc capacity emerges the next major factor in the battle of technologies: the almighty dollar. In order to manufacture a disc with such tremendous storage capability, the makers of Blu-ray have strayed far from the manufacturing technologies that have been used for years in the production of standard-definition DVDs. And that means added cost. Factories have been built or modified, adding considerable overhead cost to their production. HD-DVD, on the other hand, uses a very similar manufacturing process to that of traditional standard-definition DVDs. Thus the old factories can be recycled for the new technology, saving the companies who produce these discs an enormous sum of money. This savings is passed on to the consumer.

With huge differences in manufacture and storage capability, it may surprise you to hear that any difference in image-quality between the technologies is negligible. A sales-expert at a popular electronics super-chain put it well when he said, “I don’t know which one is better, and 99% of people out there will see no difference.” As a testament to this statement, even the fiercest supporters of either technology have had little to say about difference in image quality. The most we can get out of either camp on this is a purported 5-second advantage in disc-loading time from the Blu-ray.

So where do the Blu-ray and HD-DVD stand today? According to the latest sales numbers from Nielsen Videoscan, Blu-ray discs recently passed HD-DVD in sales by 24%. Twentieth Century Fox said at the 2007 Consumer Electronics Show that it expects to launch 10 Blu-ray titles per month this year. Lionsgate has released 10 titles so far and has another 40 or 50 titles in the works for the coming year. Sony, who is quite possibly Blu-ray’s greatest corporate ally, has a whopping 100 titles planned for this year. Representatives for Sony said at CES 2007 that they have seen a 700% increase in software sales thanks to BD players like the Playstation 3.

It is too soon, though, to make any strong prediction. Numbers have not been made available concerning hardware high-def players, and most experts are willing to admit that the game is too close to call. Until the day of comes when one technology rules the market, it will be a hard-fought battle between storage capability, price, and the strength of corporate alliances.