Amongst the many heated arguments that play out daily in chat rooms, on showroom floors, and around the water-cooler over what high-definition format is best, none is so riddled with misinformation as the argument between followers of the HDMI cable and those faithful to component. Visit any forum frequented by lovers of video, and the scenario is likely to be the same: these videophiles over here know HDMI is best, and those over there know they are wrong.
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.
Before discussing the benefits of High Definition Multimedia Interface (HDMI) switching over a direct connection, it is important to understand the benefits of HDMI. This technology first arrived on scene in early 2006. It was used in HDTV camcorders and digital still cameras. The HDMI technology helps producers of digital format videos and audio protect their products and allows for transfer of data at high rates.
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.