Everyone I talk to seems to be getting really excited about the upcoming deals at most major retailers this Friday (known as Black Friday). I am no exception to this excitement. But at the same time I can’t deny that I become saddened when I think about how many people are going to get a bargain basement price on a technology gadget this Friday that in reality is a piece of junk.I’m not saying that everything with a bargain basement price is a piece of junk. What I am saying is that some of them are. And my fear stems from the fact that noobies usually can’t tell them apart.For instance, do you know that an DVD player that upconverts to high definition is not the same as a Blu-ray high definition DVD player? Most noobies don’t. But a $60 or $70 price tag on a DVD player with the words “HD” on it sure looks like a deal! In this particular example an upconverting DVD player is not necessarily a piece of junk. In fact, they actually do a nice job of making standard DVDs look nicer on high definition televisions. But they aren’t Blu-ray, which is true 1080p high definition quality and the idea that most people think they just bought an high definition DVD player upsets me.Easy to hide inadequacies on computers and laptopsDeals on computers and laptops are another notorious rip-off. If you think you’re getting a good computer or laptop for $200 this Friday, you’re not. It may look nice on the outside but most techies would know to look for things such as how much memory it has, what the processor speed is and what kind of graphics card it has inside. A $200 laptop would fail all three of these tests.I could go on and on but I think you get the idea. But I will give you one last word of caution. Occasionally you really will find a great deal on a great technology product. But beware of the bait and switch. Most stores only carry one or two of these in their inventory. And when they run out you can bet they won’t tell you to come back another day. No, instead they will sell you on the “other” technology products still available that coincidentally aren’t all that good of a deal.So my parting advice to you is this. Trust your gut just like you would anything else. If it sounds too good to be true, it probably is. Either that or look for a good return policy.
The CEA is the preeminent trade association promoting growth in the $172 billion US consumer electronics industry. More than 2000 companies are members of the CEA, including legislative advocacy, market research, technical training and education, industry promotion, and the fostering of business and strategic relationships.
At recent CEA Industry Forums (2009), the focus has been on consumer electronics retail trends (e.g., changes in channel dynamics), 3DTV technology, green technology, and social media. CEA takes the (tentative) position that the 3DTV technology is demonstrating clear success at movie theaters and will gradually evolve into other facets of consumers’ viewing habits. But the guidance is that the industry needs to have reasonable expectations for 3DTV. 3DTV is gaining momentum, as covered in this text, but may not completely reach critical mass for several years. CEA recently observed that the top trends and technologies likely to prominently feature at upcoming international CES events are as follows: interactive TV topped the list as a trend to watch with a variety of partnerships, widgets, menus, and new ways to manage content across screens likely to generate “buzz” at upcoming CES trade shows; and 3DTV also will be a big trend, with the question of whether 3D glasses or an alternative solution will emerge as the most viable option. E-books and Netbooks were also highlighted as top 2010-and-beyond CES trends .
CEA is developing standards for the interface for an uncompressed digital interface between (say) the STB (called source) and the 3D display (called sink); these standards will need to include signaling details, 3D format support, and other interoperability requirements between sources and sinks. In 2008 CEA started standards work aimed at enabling home systems to play stereoscopic 3DTV. The group’s first step was to upgrade the interconnect standard used in the High-Definition Multimedia Interface (HDMI) to enable the cable/interface to carry stereo 3D data. Specifically this entailed an upgrade of the CEA 861 standard (A DTV Profile for Uncompressed High-Speed Digital Interfaces, March 2008) that defines an uncompressed video interconnect for HDMI. The standard defines video timing requirements, discovery structures, and a data transfer structure (InfoPacket) that is used for building uncompressed, baseband, digital
interfaces on DTVs or DTV monitors. A single physical interface is not specified, but any interface implemented must use Video Electronics Standards Association Enhanced Extended Display Identification Data (VESA E-EDID) for format discovery. CEA-861-E establishes protocols, requirements, and recommendations for the utilization of uncompressed digital interfaces by consumer electronics devices such as DTVs, digital cable, satellite or terrestrial STBs, and related peripheral devices including, but not limited to DVD players/recorders, and other related sources or sinks. CEA-861-E is applicable to a variety of standard DTVrelated high-speed digital physical interfaces such as Digital Visual Interface
(DVI) 1.0, Open Low Voltage Differential Signaling Display Interface (LDI), and HDMI specifications. Protocols, requirements, and recommendations that are defined include video formats and waveforms; colorimetry and quantization; transport of compressed and uncompressed, as well as Linear Pulse Code Modulation (LPCM), audio; carriage of auxiliary data; and implementations of the VESA E-EDID, that is used by sinks to declare display capabilities and characteristics.
At press time, CEA was also working on creating standards for 3DTV active and passive eyeglasses, metadata, on-screen displays, and user controls. A CEA group set up in 2009 was working on a standard for infrared signals used to control active shutter glasses; the group developed a requirements document and published a broad call for proposals in early 2010. The CEA also has a task group studying how to place captions in 3D space; the group was expected to issue a call for proposals in early 2010.
There is a need for a single mastering standard for viewing stereo 3D content on TVs, PCs, and mobile phones, where the content could originate from optical disks, broadcast networks, or the Internet. To that end, SMPTE formed a 3D Home Entertainment Task Force in 2008 to work the issue and a standards effort was launched in 2009 via an SMPTE 3D Standards Working Group to define a content format for stereo 3D. The SMPTE 3D Standards Working Group had about 200 participants at press time; the Home Master standard was expected to become available in mid-2010. The group is in favor of a mastering standard for the Home Master specification based on 1920 × 1080 pixel resolution at 60 fps/eye. The specification is expected to support an option for falling back to a 2D image. The standard is also expected to support hybrid products, such as BDs that can support either 2D or stereo 3D displays.
SMPTE’s 3D Home Master defines high-level image formatting requirements that impact 3DTV designs, but the larger bulk of the 3DTV standards for hardware are expected to come from other organizations, such as CEA. Studios or game publishers would deliver the master as source material for uses ranging from DVD and BD players to terrestrial and satellite broadcasts and Internet downloadable or streaming files
As we have seen throughout this text, 3DTV systems must support multiple delivery channels, multiple coding techniques, and multiple display technologies. Digital cinema, for example, is addressed with a relatively simple left–right sequence approach; residential TV displays involve a greater variety of technologies necessitating more complex encoding. Content transmission and delivery is also supported by a variety of physical media such as BDs as well as broadcasting, satellite, and cable delivery. The SMPTE 3D Group has been considering what kind of compression should be supported. One of the key goals of the standardization process is defining and/or identifying schemes that minimize the total bandwidth required to support the service; the MVC extension to MPEG- 4/H.264 discussed earlier is being considered by the group. Preliminary studies have shown, however, that relatively little bandwidth may be saved when compared to simulcast because high-quality images require 75–100% overhead and images of medium quality require 65–98% overhead. In addition to defining the representation and encoding standards (which clearly drive the amount of channel bandwidth for the additional image stream), 3DTV service entails other requirements; for example, there is the issue of graphics overlay, captions and subtitles, and metadata. 3D programming guides have to be rethought, according to industry observers; the goal is to avoid floating the guide in front of the action and instead, to push the guide behind the screen and let the action play over it because practical research shows that people found it jarring when the programming guide is brought to the forefront of 3DV images . The SMPTE Group is also looking at format wrappers, such as Material eXchange Format (MXF; a container format for professional digital video and audio media defined by a set of SMPTE standards), whether an electrical interface should be specified, and if depth representation is needed for an early version of the 3DTV service, among other factors . As we have noted earlier in the text, 3DTV has the added consideration of physiological effects because disjoint stereoscopic images can adversely impact the viewer.
An eBrochure is similar to a paper brochure. It contains all of the information you want your target market to read.
An iBrochure is similar to the eBrochure except that it implements elements of macromedia flash and page-turning capability. The iBrochures also use a simple point-and-click format, as if you were turning the pages of a brochure or magazine.
These iBrochures can be developed by you or you can have a professional develop them. There are free online sites like Issuu (http://www.issuu.com) where you can upload any pdf file and they turn it into an iBrochure within seconds. Madden Media is one of the leaders in the travel industry, developing amazing iBrochures.
Madden Media’s iBrochure for Tucson, AZ, featured in Figure 17.4, is an excellent example of how to get the most out of an iBrochure. There is the option of clicking on the specific parts of the iBrochure you are interested in reading, or you can flip through and read all pages. They have also integrated other Internet marketing techniques into their iBrochures as well, such as viral marketing with their “tell a friend” button. They have integrated the reservation software with the “book a room” button so that those who are ready to purchase do not have to go to a separate Web site. They have also used the call to action “bookmark this site” element we talked about earlier in this book. They are also giving something away for free with their “free visitor info” button.
Some iBrochures use interactive maps and calendars. Most eBrochures and iBrochures may, depending on the file size, easily be downloaded from your site, sent to customers or prospective customers via email, or handed out on CD or DVD. Both complement your existing Web site and branding strategy and open up a whole new way of communicating with existing and prospective customers. Both eBrochures and iBrochures have the advantage of easily being updated or corrected.
For the purpose of this discussion we define a mastering method as the mechanism used for representing a 3D scene in the video stream that will be compressed, stored, and/or transmitted. Mastering standards are typically used in this process.
As alluded to earlier, a 3D mastering standard called “3D Master” is being defined by SMPTE. The high-resolution 3D master file is one that is used to generate other files appropriate for various channels; for example, theater release, media (DVD, Blu-ray Disc) release, and broadcast (e.g., satellite, terrestrial broadcast, cable TV, IPTV, and/or Internet distribution). The 3D Master is comprised of two uncompressed files (left- and right-eye files), each of which has the same file size as a 2D video stream. Formatting and encoding procedures have been developed to be used in conjunction with already-established techniques, to deliver 3D programming to the home over a number of distribution channels.
In addition to normal video encoding, 3D mastering/transmission requires additional encoding/compression, particularly when attempting to use legacy delivery channels. Additional encoding schemes for CSV include the following : (i) spatial compression and (ii) temporal multiplexing.
Frame Mastering for Conventional Stereo Video (CSV)
CSV is the most well-developed and the simplest 3D video representation. This approach deals only with (color) pixels of the video frames captured by the two cameras. The video signals are intended to be directly displayed using a 3D display system. Figure 3.5 shows an example of a stereo image pair: the same scene is visible from slightly different viewpoints. The 3D display system ensures that a viewer sees only the left view with the left eye and the right view with the right eye to create a 3D depth impression. Compared to the other 3D video formats, the algorithms associated with CSV are the least complex.
A straightforward way to utilize existing video codecs (and infrastructure) for stereo video transmission is to apply one of the interleaving approaches illustrated in Fig. 3.6. A practical challenge is that there is no de facto industry standard
available (so that any downstream decoder knows what kind of interleaving was used by the encoder). However, there is an industry movement toward using an over/under approach (also called top/bottom spatial compression).
Spatial Compression. When an operator seeks to deliver 3D content over a standard video distribution infrastructure, spatial compression is a common solution. Spatial compression allows the operator to deliver a stereo 3D signal (now called frame-compatible) over a 2D HD video signal making use of the same amount of channel bandwidth. Clearly, this entails a loss of resolution (for both the left and the right eye). The approach is to pack two images into a single frame of video; the receiving device (e.g., set-top box) will, in turn, display the content in such a manner that a 3D effect is perceived (these images cannot be viewed in a standard 2D TV monitor). There are a number of ways of combining two frames; the two most common are the side-by-side combination and the over/under combination. As can be seen there, the two images are reformatted at the compression/mastering point to fit into that standard frame. The combined frame is then compressed by standard methods and delivered to a 3D-compatible TV, where it is reformatted/rendered for 3D viewing.
The question is how to take two frames, a left frame and a right frame, and reformat them to fit side-by-side or over/under in a single standard HD frame. Sampling is involved, but as noted, with some loss of resolution (50% to be
exact). One approach is to take alternative columns of pixels from each image and then pack the remaining columns in the side-by-side format. Another approach is to take alternative rows of pixels from each image and then pack the remaining rows in the above/under format (Fig. 3.7).
Studies have shown that the eye is less sensitive to loss of resolution along a diagonal direction in an image than in the horizontal or vertical direction. This allows the development of encoders that optimize subjective quality by sampling
each image in a diagonal direction. Other encoding schemes are also being developed to attempt to retain as much of the perceived/real resolution as possible. One approach that has been studied for 3D is quincunx filtering. A quincunx is a geometric pattern comprised of five coplanar points, four of them forming a square (or rectangle) and a point fifth at its center, like a checkerboard. Quincunx filter banks are 2D two-channel nonseparable filter banks that have been shown to be an effective tool for image coding applications. In such applications, it is desirable for the filter banks to have perfect reconstruction, linear phase, high coding gain, good frequency selectivity, and certain vanishing-moment properties
[7–12]. Almost all hardware devices for digital image acquisition and output use square pixel grids. For this reason and for the ease of computations, all current image compression algorithms (with the exception of mosaic image compression for single-sensor cameras) operate on square pixel grids. It turns out that the optimal sampling scheme in the two-dimensional image space is claimed to be the hexagonal lattice; unfortunately, a hexagonal lattice is not straightforward in terms of hardware and software implementations. A compromise, therefore, is to use the quincunx lattice; this is a sublattice of the square lattice, as illustrated in Fig. 3.7. The quincunx lattice has a diamond tessellation that is closer to optimal hexagon tessellation than square lattice, and it can be easily generated by down-sampling conventional digital images without any hardware change. Because of this, quincunx lattice is widely adopted by single-sensor digital cameras to sample the green channel; also, quincunx partition of an image
was recently studied as a means of multiple-description coding . When using quincunx filtering, the higher-quality sampled images are encoded and packaged in a standard video frame (either with the side-by-side or over/under arrangement). The encoded and reformatted images are compressed and distributed to the home using traditional means (cable, satellite, terrestrial broadcast, and so on).
Temporal Multiplexing. Temporal (time) multiplexing doubles the frame rate to 120 Hz to allow the sequential repetitive presentation of the left eye and right eye images in the normal 60-Hz time frame. This approach retains full resolution for each eye, but requires a doubling of the bandwidth and storage capacity. In some cases spatial compression is combined with time multiplexing; however, this is more typical of an in-home format and not a transmit/broadcast format. For example, Mitsubishi’s 3D DLP TV uses quincunx sampled (spatially compressed) images that are clocked at 120 Hz as input.
Compression for Conventional Stereo Video (CSV)
Typically, the algorithms to compress act to separately encode and decode the multiple video signals, as shown in Fig. 3.8a. This is also called simulcast. The drawback is the fact that the amount of data is increased compared to 2D video; however, reduction of resolution can be used as needed, to mitigate this requirement. Table 3.1 summarizes the available methods.
It turns out that the MPEG-2 standard includes an MPEG-2 Multi-View Profile (MVP) Coding that allows efficiency to be increased by combining temporal/inter-view prediction as illustrated in Fig. 3.6b.H.264/AVC was enhanced a few years ago with a stereo Supplemental Enhancement Information (SEI) message that can also be used to implement a prediction as illustrated in Fig. 3.8b. Although not designed for stereo-view video coding, the H.264 coding tools can be arranged to take advantage of the correlations between the pair of views of a stereo-view video, and provide very reliable and efficient compression performance as well as stereo/mono-view scalability .
For more than two views, the approach can be extended to Multi-view Video Coding (MVC) as illustrated in Fig. 3.9 ; MVC uses inter-view prediction by referring to the pictures obtained from the neighboring views. MVC has been standardized in the Joint Video Team (JVT) of the ITU-T Video Coding Experts Group (VCEG) and ISO/IEC MPEG. MVC enables efficient encoding of sequences captured simultaneously from multiple cameras using a single video stream. MVC is currently the most efficient way for stereo and MVC; for two views, the performance achieved by H.264/AVC stereo SEI message and MVC are similar . MVC is also expected to become a new MPEG video coding standard for the realization of future video applications such as 3D Video (3DV) and Free Viewpoint Video (FVV). The MVC group in the JVT has chosen the
H.264/AVC-based MVC method as the MVC reference model, since this method showed better coding efficiency than H.264/AVC simulcast coding and the other methods that were submitted in response to the call for proposals made by the MPEG [15, 17–20].
Some new approaches are also emerging and have been proposed to improve efficiency, especially for bandwidth-limited environments. A new approach uses binocular suppression theory that employs disparate image quality in left- and right-eye views. Viewer tests have shown that (within reason), if one of the images of a stereo pair is degraded, the perceived overall quality of the stereo video will be dominated by the higher-quality image [16, 21, 22]. This concept
is illustrated in Fig. 3.10. Applying this concept, one could code the right-eye image with less than the full resolution of the left eye; for example, downsampling it to half or quarter resolution (Fig. 3.11). Some call this asymmetrical
quality. Studies have shown that asymmetrical coding with cross-switching at scene cuts (namely alternating the eye that gets the more blurry image) is a viable method for bandwidth savings . In principle this should provide comparable
overall subjective stereo video quality, while reducing the bitrate: if one were to adopt this approach, the 3D video functionality could be added by an overhead of say 25%–30% to the 2D video for coding the right view at quarter resolution.
The past decade has been an amazing time for home theater enthusiasts. Improved manufacturing techniques and global
market competition has brought high-end A/V equipment into the mainstream. Competition among flat panel TV manufacturers has been particularly fierce. However, to keep costs down to a minimum, many of these products are shipped with near useless user manuals and throwaway A/V cables.
A quick glance at the back of a typical HDTV can be quite intimidating. There will often be 10 or more types of connections, many of which appear redundant. So what type of connection yields the best picture or sound quality?
What kind of cable is required? We created the Amphenol Cables on Demand Home Theater Cable Guide to answer these A/V questions.
The HDMI or High Definition Multimedia Interface is the A/V connection of choice on the latest generation of home theater equipment. HDMI supports high resolution digital video with resolutions up to 1920×1080 (1080p) as well as multichannel digital surround sound over a single low-profile cable. Since HDMI is a digital interface, interference problems such as ghosting, snow, and hum are eliminated entirely. If you have HDMI inputs on your HDTV, you must use an HDMI compatible signal source to take advantage of them. All new HDTV compatible cable and satellite set-top-boxes come standard with HDMI; as do the new HD-DVD and Blu-ray Disc Players.
HDMI cables must be built to extremely tight tolerances in order to support the bandwidth requirements of today’s video sources. We use our 70+ years of interconnect manufacturing experience to ensure these strict tolerances are met. Amphenol HDMI cables are designed to the latest specification: HDMI 1.3. For those running 1080p, we recommend our Premium 1080p Certified HDMI cable series.
Now that the personal computer has become the centerpiece for storing movies, music, and pictures, it’s no surprise that the SVGA connection has migrated over to the average HDTV. Now, with a simple cable, you can play PC based video games or browse the web on the big screen. Amphenol SVGA cables feature precision-terminated HD15 connectors and double-shielded coax; perfect for high-bandwidth 1080p HDTV signals. We recommend SVGA cables with Ferrites for commercial installations.
The Y’PbPr analog component video connection made its major debut with the release of the DVD player in the mid 90s. Shortly thereafter, component video became standard equipment on nearly every HDTV and home theater projector.
Although component video does not quite meet the performance level offered by HDMI, it still reliably supports 1080p true high definition video content. We recommend component video cables for use with DVD players whenever possible to support the Progressive Scan feature. RCA audio cables are not suitable for component video use. Proper component video cables are color coded in red, blue, and green.
The S-Video or “separate video” connection splits the analog video signal into a color component and a brightness component. S-Video is the preferred connection method for use with standard definition (480i) content. S-Video connections were often considered a premium on older tube TV’s, as they delivered a sharper picture from sources like S-VHS VCR’s, cable boxes, and satellite receivers. S-Video has the distinction of eliminating the problem of dot crawl, which consists of animated checkerboard patterns that appear along vertical color transitions. All Amphenol S-Video
cables are fully molded and shielded for exemplary performance and reliability. Premium Gold version available.
Composite video is perhaps the most widely used analog video interface found on consumer electronic equipment. A composite video connector can easily be located by its yellow color. It is called composite video because the color, sync, and brightness information is all combined into a single signal. Composite video is convenient and easy to work with since it demands minimal bandwidth and can be used over common 75 ohm coaxial cable. Composite video is always recommended for use with laser disc players, but is generally a lesser choice for other equipment if an S-Video,
component, or HDMI connection is available.
RF Audio / Video
An RF signal combines both video and audio and modulates it onto a TV channel. If you have to turn the TV to channel 3 or 4 in order to watch your cable box or VCR, you are likely using an RF connection. We do not recommend using the RF connection on new A/V equipment unless absolutely necessary. If you simply need to hook up a VCR to a spare TV, this connection will work fine. Our special thin-line RF cables feature low-profile F connectors for maximum installation flexibility.
The TOSLINK interface was initially developed by Toshiba as a low cost method of digitally linking CD players and stereo receivers. As digital surround sound entered the home market, TOSLINK was adapted to handle the new format. TOSLINK ports were soon added to cable/satellite boxes, DVD players, and game consoles. The audio delivered via TOSLINK offers superior fidelity and is completely immune to interference due to its fiber optic design. We recommend using a digital connection like TOSLINK whenever possible. TOSLINK ports are easily recognized by their distinctive
Analog Stereo RCA audio connections are widely implemented. Nearly every piece of home theater equipment on the market is equipped with one or more sets of Stereo RCA jacks. Stereo RCA connections are an ideal choice for use with devices that do not support digital surround sound such as CD players and VCR’s. To fully capture the multi-track digital surround sound embedded on most DVD’s and HDTV shows, a digital connection such as TOSLINK is required. Amphenol Stereo RCA cables are properly impedance matched for flawless audio reproduction.
The 3.5mm Mini-Stereo connection, often called the headphone jack, is commonly installed on portable electronic devices such as MP3 players and handheld games. Many home and car stereos now come equipped with a 3.5mm Mini-Stereo auxiliary input jack. Our 3.5mm male / male cable is perfect for connecting your portable device to this input jack. If you need to extend a pair of headphones or another cable, use our 3.5mm male / female cable.
The first multitouch system designed for human input was developed in 1982 by Nimish Mehta of the University of Toronto. Bell Labs, followed by other research labs, soon picked up on Mehta’s idea. Apple’s 2007 launch of the iPhone, which is still the point of reference today for multitouch experiences and gestures, popularized a new form of user interaction.
More recently, Microsoft launched Windows 7, Adobe added multitouch and gesture capability to Flash Player and AIR, and a range of smartphones, tablets, and laptops that include multitouch sensing capability have become available or are just entering the market. Common devices such as ATMs, DVD rental kiosks, and even maps at the local mall are increasingly equipped with touch screens.
For an in-depth chronology, please read Bill Buxton’s article at http://www.billbuxton.com/multitouchOverview.html.
Exploring the use of alternate input devices in computing is often referred to as physical computing. For the past 20 years, this research has advanced considerably, but only recently has it been reserved for exhibitions or isolated equipment installations. These advances are now starting to crop up in many consumer electronics devices, such as the Nintendo Wii, Microsoft Xbox, and Sony PlayStation Move.
A playful example of a human–computer interface is the Mud Tub. Created by Tom Gerhardt in an effort to close the gap between our bodies and the digital world, the Mud Tub uses mud to control a computer. For more information, go to http://tomgerhardt.com/mudtub/.
For our purposes, we will only use clean fingers and fairly predictable touch sensors.
A home theater system is ultimate in home entertainment. A treat for movie buffs and just about anyone, home theater systems get pulses racing by bringing the cinematic experience, right into our homes. Most home theater systems, or home theaters in a box, include a DVD or up-scaling DVD player, an A/V Receiver, five — but in some sets seven – speakers, and a Sub-woofer. These speakers are strategically placed around the listener – creating an immersive theatrical experience. A home theater experience is the next best thing to the movie theater’s sound system. It’s true that the sound effects, dialogue, and ambient sounds from movie sound tracks can be heard as they were intended when played through these systems, but the true essence of a home theater system is, convenience. Their greatest draw is their ability to streamline
shopping. Unless you’re a serious audiophile, or looking to get the cops called for disturbing the peace, you won’t want to build a system from components purchased separately, and you’ll find the sound output quality from HTiBs to be outstanding.
- With or without a DVD player: Some systems include only a receiver and matching speakers, matching in look as well as in power handling.
- Player types: Many systems include up-scaling players that process and reformat DVDs to High Definition. Blu-ray home theater systems are a relatively new offering and prices are becoming very reasonable. Players integrated into the receiver are also available for those that prefer a cleaner look.
- Wireless speakers or multi-room audio: Rear channel wireless speakers eliminate the need for wire running form the front to the back of the room. On some systems all the speakers are wireless. A few systems offer transmitters that can send the audio signal from your receiver to other compatible wireless speaker situated in other rooms of
- iPod dock, WiFi connectivity: iPod docks allow you to easily interface your iPod with the sound system, as well as charge its battery. WiFi connectivity is a feature that allows the home theater system to interface with your computer’s HDD, any media files can then be accessed for play thru
- The speakers: Speakers come in different shapes and sizes, micro speakers that either sit on a shelf or mount to the wall or stand are a popular option, but, Increasing speakers styling has emulated TV designs by going thinner and taller, or being framed in piano black or silver. It is the speakers that distinguish a home theater system from any
audio entertainment system. The mandatory speakers that a package must have to be considered a home theater system are:
- Center channel speaker: This speaker directly faces the viewer and can be placed either under the television or above it. This speaker emits the main dialog and sound effects.
- Left and right front speakers: These speakers could also be placed at approximately a 45 degree angle on either side of the television or preferably at the two front corners of the room with the sound waves converging on the center of the rear wall of the room These are the primary pair of speakers in the system, providing the first level of sound output. If the sound jars, these speakers should be placed directly facing the viewer.
- Left and right rear satellite surround sound speakers: These speakers should be ideally placed in either corner of the rear wall. It is these speakers that are responsible for the viewer getting the feeling of actually being ‘into’ the scene of the movie. Any audio related to occurrences at the corners of the screen, such as a character talking towards one side of the screen or a vehicle driving past or approaching the camera, is transmitted to these speakers, on the same side as the action on the screen.
- Subwoofer: This speaker is responsible for the low frequency bass sounds. Great for viewing a rock concert, this speaker adds to the feel of the home theater system.
- Audio/Video receiver: Almost no home theater system is complete without this component. The receiver controls the video display on the screen and the sound output from all the speakers. The receiver has the audio/video inputs for the DVD player or the VCR, a surround sound decoder, a preamplifier, power amplifiers for each sound
channel, as well as outputs to the speakers and the television or projector. The decoder can be either analog or digital, this device being responsible for the picture on the screen and sound from the speakers. The video output is sent to the display device and the sound output is sent to the decoder which separates sound input with respect to the relevant sound channels, the relevant outputs being sent to the correct speaker.
What to look for in a home theater system
Considering the various components of a home theater system and the many surround sound speakers available in the market, purchasing the system of your choice may not always be easy. Below we have listed a few pointers which would help at the time of purchase:
- Surround sound format: This requirement ensures proper sound. The home theater receiver should be able to split sound signals from all audio formats, such as DTS, (Digital Theater System), Dolby Digital, Dolby Pro Logic, and Dolby Pro Logic-II (an encoding system that digitally compresses 5 to 7 unique audio channels). A 5.1 speaker
system includes 5 speakers and one subwoofer. This is the most common configuration for home theater system speakers.
- Wide spectrum speaker system: The speaker system should encompass the whole audible audio frequency range. Thus, reproduction of even the faintest sound effects is possible with almost negligible phase and time distortion. The audible frequency range in humans varies from 20 to 20,000 Hz.
- Recording format compatibility: This point is concerned with the DVD player. The DVD player of your home theater system should be compatible with all disc formats that include DVD-Audio, DVD-Video, DVD-RW, DVD-R, +RW, +R, CD, CD-R/RW, SVCD/VCD, MP3/WMA/JPEG Digital Still (CD-R/RW, DVD-R/RW), MPEG-4 (ASP)/DivX (CD-R/RW, DVD-R/RW). MPEG-4 and DivX are especially important today where movies in these formats are increasingly becoming available.
- Video Up-sampling: This has to do with improving video quality by increasing the signal bandwidth. The system should have an up-sampling rate of 4x.
- Digital to Analog converter (DAC): Before display on the screen, all digital signals of a video transmission need to be converted to analog signals. The DAC ensures that this task is carried out. Higher the bit range used by the DAC, better the signal quality. The home theater system should have a minimum 24 bit DAC converter.
- Signal to Noise ratio: This represents the ratio of the audio signals to the noise output, measured in decibels. Higher the S/N ratio the better the sound quality.
- Progressive scan: Earlier technologies created images on the display screen line-wise, with odd lines being drawn first and then, even lines, resulting in a picture that was not all that clear. However, in progressive scan technology, both lines are displayed together, making for a sharper picture.
- Aspect ratio: This is the ratio of image width to image height. While analog television pictures have an aspect ratio of 4:3, High Definition TVs (HDTVs) have an aspect ratio of 16:9.
- Impedance: This implies the total resistance offered by a conductor to the flow of alternating current across a circuit at a certain frequency. Low impedance translates into more efficient distribution of power.