WAKTU DAN KETIKA

WAKTU DAN KETIKA

di suatu waktu
di suatu ketika
dulu...

aku disini
duduk menghitung waktu
pada jam usang tinggalan arwah tok ku

tik.. tik... tik...
apa yang mau kau isyaratkan?
sekian abad kau bergerak
mengapa kau masih enggan berbicara?





Rabu Sept 17, 2003 2:43 pm

Revolusi tv...

hitam putih
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Warna
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cembung
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skrin rata
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LCD
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Plasma
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3D
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Mana satu pilihan anda...?

Komunikasi semut

Penelitian ilmiah tentang semut menunjukkan adanya jaringan komunikasi yang luar biasa di antara makhluk ini. Dalam artikel di majalah National Geographic menjelaskan:

Semut berkomunikasi dengan mengeluarkan bebauan dari tubuhnya. Zat kimia yang dikeluarkan oleh semut dari koloni yang sama adalah berbeza dengan koloni yang lain. Itulah sebabnya jika dua semut bertemu akan saling menyentuh untuk saling "membaui" dan mengetahui asal-usul masing2. Jejak ini juga digunakan semut pekerja sebagai penanda tempat.

Semut juga memiliki metode komunikasi yang cukup berbeza daripada organ pancaindera mereka yang peka. Mereka menggunakan organ pancaindera ini setiap saat dalam hidup mereka, dari menemukan mangsa hingga saling mengikut sesamanya, dari membangun sarang hingga bertarung...

Al Quran memberi informasi menarik ketika kita membicarakan tentara Nabi Sulaiman as. dan menyebut adanya "sistem komunikasi" yang maju di antara semut. Ayat itu sebagai berikut:Hingga apabila mereka sampai di lembah semut, berkatalah seekor semut: "Hai semut-semut, masuklah ke dalam sarang-sarangmu, agar kamu tidak diinjak oleh Sulaiman dan tentaranya, sedangkan mereka tidak menyedari.

(Surat An-Naml: 18)

Anytime With Home Entertainment Theatre Systems

It is fun to go to the theatre to watch a movie with friends, but most people prefer to relax at home with home entertainment theatre systems. Watching movies at the theatre can run into mega bucks, if you decide to visit the concession stand. Drinks alone can run up a bill of over $20 if four people are watching the movie.

The cost of the movies seen on a home entertainment movie screen would cost about $4.00. People that value their time can value the simplistic approach to watching movies at home. Movie time is fun time with friends because movies can be seen at anytime.

Many people have upgraded their home televisions to include surround sound and when shopping for these systems, it is not improbable to find many of them on sale. During recent holiday shopping jaunts, shoppers found home entertainment systems and surround sound systems on sale. Retailers were hoping to entice customers to buy so that new inventories could be moved onto the showroom floor. These home entertainment systems were hot sellers during the past holiday season.

HDTV

High-definition television (or HDTV) is a digital television broadcasting system with higher resolution than traditional television systems (standard-definition TV, or SDTV). HDTV is digitally broadcast; the earliest implementations used analog broadcasting, but today digital television (DTV) signals are used, requiring less bandwidth due to digital video compression.

Plasma TV vsLCD

When choosing between LCD and plasma TVs, you're actually selecting between two competing technologies, both of which achieve similar features as bright, crystal-clear images, super color saturated pictures and come in similar packages .To complicate the decision-making process further, price and size are two previous considerations that are rapidly becoming non-issues as LCDs are now being made in larger sizes and at competing prices with plasma TVs.

Despite all these similarities, these technologies differ in how they process and display incoming video/computer signals. Plasma flat screen technology consists of hundreds of thousands of individual pixel cells, which allow electric pulses (stemming from electrodes) to excite rare natural gases-usually xenon and neon-causing them to glow and produce light. This light illuminates the proper balance of red, green, or blue phosphors contained in each cell to display the proper color sequence from the light. Each pixel cell is essentially an individual microscopic florescent light bulb, receiving instruction from software contained on the rear electrostatic silicon board. Look very closely at a plasma TV and you can actually see the individual pixel cell coloration of red, green, and blue bars. You can also see the black ribs which separate each.

Whether spread across a flat-panel screen or placed in the heart of a projector, all LCD displays come from the same technological background. A matrix of thin-film transistors (TFTs) supplies voltage to liquid-crystal-filled cells sandwiched between two sheets of glass. When hit with an electrical charge, the crystals untwist to an exact degree to filter white light generated by a lamp behind the screen (for flat-panel TVs) or one projecting through a small LCD chip (for projection TVs). LCD monitors reproduce colors through a process of subtraction: They block out particular color wavelengths from the spectrum of white light until they're left with just the right color. And, it's the intensity of light permitted to pass through this liquid-crystal matrix that enables LCD televisions to display images chock-full of colors-or gradations of them.

Dolby VS DTS

Perhaps the most controversial question asked in the context of DVDs is: does DTS sound better than Dolby Digital? As in so many debates, there is the strong position and the weak one. The strong position is that, yes, of course DTS sounds better. The weak one comes from those who have listened to both and, often shamefacedly, admit that they can't tell any difference.

Naturally, DTS advocates are in the winning position because they can say that they have heard a difference. The poor old Dolby Digital defenders look like they have cloth ears. But before we delve too deeply into the debate, let's look at what the two formats are, and where they came from.

Neither was developed for DVD. Both were intended to provide 5.1 discrete channels of digital sound in cinemas on 35mm film while remaining fully compatible with standard equipment. Dolby placed its digital sound track as optical marking on the edge of the film, between the sprocket holes. This left Dolby with a bandwidth of around 400 kilobits per second. Six channels of uncompressed CD-quality digital audio requires ten times this capacity, so Dolby developed AC-3, an MPEG-type 'lossy' audio compression system.

Turtle Beach ?

Wireless Xbox 360 Headphones with Improved Xbox Live Chat and Dolby 5.1 Surround Sound
The Ear Force® X4 wireless headphones push your Xbox 360™ gaming experience to a whole new level with the thrill and realism of Dolby® Digital 5.1-channel surround sound. Pump up the volume without disturbing friends, family, or neighbors. Freely move around as you play. Hear every nuance of the game—from an opponent sneaking up behind you to your teammate's voice right next to you. Trash-talk online. Block out distractions. Feel the game expand all around you and become a better player.

Features

• Enjoy Dolby Digital 5.1 surround sound with your favorite games and DVD movies
• Dolby Pro Logic® II provides surround sound from Pro Logic II encoded audio and also enhances stereo
• Hear Xbox Live® Chat plus stereo game sound
• Heart-thumping bass boost adds sonic realism
• Dynamic Talkback lets you hear chat even when the game gets louder
• Separate controls for game and chat volumes
• Eliminates game sounds picked up by chat mic
• Mic Monitor lets you hear what you're saying
  

Dolby Pro Logic

Dolby Pro Logic is a surround sound processing technology designed to decode soundtracks encoded with Dolby Surround. Dolby Surround Stereo was originally developed by Dolby Laboratories in 1976 for analog cinema sound systems. The format was adapted for home use in 1982 as Dolby Surround when HiFi capable consumer VCRs were earlier introduced and was then replaced by the newer and improved Pro Logic system in 1987. However, the term "Dolby Surround" is still used to describe the encoding technology or matrix-encoded soundtrack, whereas Pro Logic refers to the decoding technology/processor. It is the domestic equivalent of the theatrical Dolby Stereo technology used in movie cinemas in the 1970s and '80s. The two technologies are mostly identical but a change in marketing was needed so as not to confuse cinema stereo which is at least four channels of audio with home stereo which is only two. Thus Dolby Pro-Logic is the consumer version of theatrical Dolby stereo.

Dolby Surround/Pro Logic is based on basic matrix technology. When a Dolby Surround soundtrack is created, four channels of sound are matrix-encoded into an ordinary stereo (two channel) sound track by using phase shift techniques. A Pro Logic decoder/processor "unfolds" the sound into the original 4.0 surround—left and right, center, and a single limited frequency-range mono rear channel—while systems lacking the decoder play back the audio as standard Stereo.

Although Dolby Surround was introduced as an analog format, all Dolby Digital decoders incorporate a digitally implemented Dolby Surround Pro Logic decoder for digital stereo signals that carry matrix-encoded Dolby Surround.

Latest Home Theater

Klipsch and Circuit City have made a deal that would bring the Klipsch and Energy brands to 700 stores across the country. It would also make many of those selections available online.
For the Klipsch brand, the store will feature the Synergy Series, which includes floorstanding and bookshelf speaker models, as well as center-channel, surrounds, and subwoofers. Pricing ranges from $250 to $900 per pair. The company says that a five-speaker home theater set will also be available.

Don’t expect many Energy speakers; the store will only carry the six-piece Take Classic system, which will run for $600.

“They say a picture is worth a thousand words, but in a home theater, a picture can only be as good as it sounds,” said Philip J. Schoonover, chairman, president and CEO of Circuit City. “With the Klipsch and Energy brands, our customers will truly be investing in world-class audio to match their world-class home entertainment system,”

Home Theater system ; Dolby Digital, DTS

Delivers 5 audio channels and 1 LFE channel from a 6 channel source:

• Two channels for speakers at the front - left (L) and right (R).
• One channel for speaker at the center - center (C).
• Two channels for surround speakers at the rear - surround left (LS) and surround right (RS).
• One low-frequency channel using a sub-woofer (LFE).
• Describes the Dolby and DTS Surround systems. Source media, usually DVD and
• sometimes Laserdisc or satellite/digital cable is often branded with "Dolby Digital" and/or DTS logos.
• DTS uses a higher sampling rate than Dolby Digital, thus DTS uses less compression and achieves higher fidelity than Dolby Digital.
• Surround Sound speaker placement: (6 speakers in total) Surround Sound speaker placement is different for both music and movie content.

For music speakers are placed in a circle around the listener. The center channel has 0º offset, left and right are offset ± 30º, and the left/right surrounds are offset by ±110º. Also all speakers should be monopole, equidistant to the listener, and all delay (ms) calculations on the surround decoder should be turned off (0ms).

For movie surround, the front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a tv, and as close to ear high as possible. Rear channel speakers should be placed high on side walls, slightly behind the listening position, and should have a nomal hi quality monopolar construction.

Home Theater system ; 5.1 Surround (matrixed Prologic II)

Extracts 5 audio channels from a stereo source:

• Three for speakers at the front - left (L) and right (R) at 22-30°, and center (C).
• Two for surround speakers at 90-110° to the side or rear - stereo surround left (LS) and surround right (RS).
• One low-frequency channel using a sub-woofer (Sub).
• Describes the Dolby Prologic II matrixed Surround systems, with stereo rear surround channels.
• Surround Sound speaker placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a tv, and as close to ear high as possible. Rear channel speakers should be placed high on side walls, slightly behind the listening position, and should have a di-pole construction.

Home Theater system ; 4.1 Surround (matrixed Prologic)

4.1 Surround (matrixed Prologic)

Extracts 4 audio channels from a stereo source::

• Three for speakers at the front - left (L), center (C) and right (R).
• One for both surround speakers at the rear - mono surround channel (S).
• One low-frequency channel using a sub-woofer.
• Describes the Dolby Prologic matrixed Surround systems, with mono rear surround channels.
• Surround Sound speaker placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. The center speaker should be placed behind the screen (when using projection) or over or under a tv, and as close to ear high as possible. Rear channel speakers should be placed high on side walls, slightly behind the listening position, and can be of smaller size, due to the frequency limitations of the surround channel.

Home Theater system ; 4.0 Surround (matrixed Quadraphonic)

Extracts 4 audio channels from a stereo source:

• Two for speakers at the front - left (L) and right (R).
  
• Two for surround speakers at the rear - surround left (LS) and surround right (RS).
  
• Describes the early matrixed Surround Quadraphonic, Quadraphonic Stereo and other systems.
  
• Surround Sound speaker placement: The front speakers should be placed at the edges of the screen, toed in to face the central listening location, and the tweeters should be ear height. Rear channel speaker should be placed high on the back wall, slightly behind the listening position, and can be of smaller size, due to the frequency limitations of the surround channel.

Surround Sound Spec

Surround Sound is the concept of expanding the spatial imaging of audio playback from one dimension (mono/Left-Right) to two or three dimensions.

This is often performed for a more realistic audio environment, actively implemented in cinema sound systems, technical theatre, home entertainment, video arcades, computer gaming, and a growing number of other applications.

Many popular surround sound formats have evolved over the years. They include discrete 5.1 Surround sound on DVD-Audio (DVD-A) or SACD (Super Audio CD), ambisonics, quadraphonic, Dolby 5.1 Surround sound, DTS, DVD-Video (DVD-V), and MP3 Surround.

3.0 Surround (matrixed)

Extracts 3 audio channels from a stereo source:

* Two for speakers at the front - left (L) and right (R).
* One for surround speaker at the rear - surround (S).
* Describes the early matrixed Dolby Surround system.
* Surround Sound speaker placement: Three identical speakers placed equidistant around a central listening position.

More...

Dolby Pro Logic II

A much improved decoding system for Dolby Stereo encoded material and also caters to the decoding of non-encoded material such as regular two channel music. It differs from it predecessor by achieving a more intelligent extraction of the channels, so much so that instead of a single surround signal, Dolby Pro Logic II yields stereo left and right surrounds. For compatibility with movies and other Dolby Stereo encoded material, Pro Logic II has a Movie mode. Because non-encoded material such a music more often than not collapses to center (all the sound seems to come just from the center speaker), Pro Logic II also has a Music mode which works extremely well and can include user access to parameters to customize the sound field.

Surround EX
Dolby Digital Surround EX first appeared in movie theaters with Star Wars Episode I: The Phantom Menace. This system starts from a standard Dolby Digital 5.1 soundtrack but then applies a form of Pro Logic decoding to the two rear channels only, and derives a third surround channel, positioned between the other two. So from a 5.1 soundtrack, Dolby Digital Surround EX derives a 6.1 soundtrack.

This new system first became available to the home market on THX equipment as THX Surround EX because THX co-created the new system. It is now available on non-THX decoders as Dolby Digital EX. Ideally, a soundtrack needs to have been crafted for this system in order for it to sound right. The surround sound information of non-EX encoded tracks can come out predominantly from the center surround channel and lose spaciousness.

DTS ES and ES Discrete
DTS also delivered some 6.1 systems. The first, DTS ES, is in all practicality the same process as Dolby Digital EX in that the playback system applies a matrix decoder to the two surround channels to derive a third between them. DTS ES Discrete on the other hand actually added a sixth discrete main channel. Where as there are precious few Dolby Surround EX soundtracks on DVD, there are even fewer DTS ES and fewer still DTS ES Discrete. That sixth channel has just not been very successful.

Dolby Pro Logic IIx
Dolby Pro Logic IIx takes virtually any source track, be it two channel or 5.1, and yields up to seven channels of sound by employing the latest in matrix decoding technology.

Surround Sound Formats

Dolby Pro Logic
Dolby Pro Logic, like Dolby Stereo in the movie theater, converts two tracks of sound into four channels. In the days of Laserdisc and Stereo VHS it literally was the only thing going. While dated and overshadowed by newer technology, Dolby Pro Logic remains vital: It is used whenever the medium is limited to two channel and may even be used when technology permits more, in order to save space or preserve the artistry of an original audio work.

Dolby Digital

Dolby Digital (also known as the AC-3 Codec) was first made available to consumers on special Laserdiscs. It came into the mainstream when it was chosen as the multi-channel codec for the DVD Video format. It is an extremely flexible codec which can carry from 1 to 6 completely separate and independent channels of digital sound. The full six-channel configuration consists of the front left, center, front right, rear left and right, and the LFE channel (or Low Frequency Effects channel). The LFE channel has a restricted frequency range, while all the other channels are full range (8 Hz - 20 kHz), so the system is often called "5.1".

While two channel CD Audio has about a 1.5 mbps bitstream, Dolby Digital uses as little as 384 kbps in total for all six channels. Obviously, this requires considerable compression of the audio data (about 10:1). Dolby utilizes "Perceptual Encoding" for this process, putting only those sounds that the brain would pay attention to in the sound tracks. This necessitates very sophisticated algorithms (a series of mathematical formulas) to determine what to include and what to eliminate. In practice, the sound quality is spectacular. While initially a very expensive system for consumers, every surround sound decoder on the market now has Dolby Digital as part of the feature set.

DTS

Digital Theater Systems, or DTS, is another 5.1 digital surround sound format, first developed for movie theaters and then later appearing in homes on Laserdiscs. It is now technically an optional format for DVD. The system utilizes a completely different lossy compression codec from AC-3, and only manages a 5:1 compression. The term "Lossy" means that some of the data are lost during compression, and cannot be restored when the bitstream is decoded. This is contrasted to the term "Lossless", which means that the compression codec (the combination of algorithms used to compress and uncompress the digital data) does not throw away any data, and the original data are restored when they are decoded.

There are some who feel that the DTS codec results in better sound because it uses less compression, but because the two codecs are different, the bitrates cannot be compared at face value (i.e., it could simply be that DTS is less efficient than AC-3 as opposed to actually sounding better). We at Secrets have never been able to definitively show that DTS sounds any better than Dolby Digital. Whereas DTS used to come at a premium price, it is now found on virtually every surround sound decoder on the market.

Speakers Of Home Theater

You want to get the best home theater speakers for your money, so there are many things to consider before laying down your cash. Home theater speakers may sound great in the store, but when you get them home they may sound completely different. The best home theater speakers are the ones that sound great in your home.

How can you tell what will sound good at home? Choose the best home theater speakers is by comparison shopping. Listen closely to different home theater systems. If you already have a receiver, make sure you listen to speaker systems through the same kind of receiver, otherwise you may get a different sound when you take the speakers home.

Narrow your selection down to two or three sets of speakers and compare them while watching that DVD that you are familiar with. As the movie is playing, switch between the various sets so you can hear the difference between the speaker systems. This will allow you to pick the best home theater speakers the store has to offer.

Once you bring your speaker system home, consider the acoustic properties of your home theater room. Ideally, it should be acoustically “dead” -no echos or reverberations. This is pretty hard to achieve in a home environment, but if you install wall-to-wall carpeting and cover the windows with curtains, you will improve the acoustics and allow the best home theater speakers to reach their potential.

Projection Screen

Projection screens are installations consisting of blank surface and a support structure used for projecting an image for the view of an audience. Projection screens may be permanently installed as in a movie theater, painted on the wall, semi-permanent or mobile, as in a conference room or other non-dedicated viewing space.

Uniformly white or grey screens are used almost exclusively as to avoid any discoloration to the image, while the most desired brightness of the screen depends on a number of variables, such as the ambient light level and the luminous power of the image source.

Flat or curved screens may be used depending on the optics used to project the image and the desired geometrical accuracy of the image production, flat screens being the more common of the two. Screens can be further designed for front or back projection, the more common front projection systems having the image source situated on the same side of the screen as the audience.

Home theater projection screen displaying a high-definition television image.Different markets exist for screens targeted for use with digital projectors, movie projectors, overhead projectors and slide projectors, although the basic idea for each of them is very much the same: front projection screens work on diffusely reflecting the light projected on to them, whereas back projection screens work by diffusely transmitting the light through them.

Projector

A video projector takes a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for conference room presentations, classroom training, and home theater applications.

Video projectors may also be built into cabinets which use a rear projection screen to form a single unified display device, now popular for "home theater" applications.

The cost of a device is not only determined by its resolution, but also by its brightness. While most modern projectors will provide sufficient brightness at night or under controlled lighting such as in a basement with no windows, a projector with a higher lumens rating is required for a room with a higher amount of ambient light. A rating of 1000 to 1500 ANSI lumens or lower is suitable for smaller rooms with controlled lighting or low ambient light. Between 1500 to 3000 ANSI is suitable for medium sized rooms with some ambient light or dimmed light. Over 3000 ANSI is appropriate for very large screens in a large room with no lighting control (for example, a conference room). Projected image size is also important, as the total amount of light does not change, as size increases, brightness decreases. An increase in a widescreen image from 80 inches diagonal to 100 inches diagonal reduces the image brightness by 35 percent.