Wednesday, March 7, 2007

Consumer Reports - Receivers

The receiver is the brain of an audio/video system. It provides AM and FM tuners, amplifiers, surround sound, and switching capabilities. It’s also the heart of the setup--most of the devices in a home-entertainment system connect to it, including audio components such as speakers, a CD player, cassette deck, and turntable, as well as video sources such as a TV, DVD player, VCR, and cable and satellite boxes. Even as receivers take on a bigger role in home entertainment, they’re losing some audio-related features that were common years back, such as tape monitors and phono inputs. Manufacturers say they must eliminate those less-used features to make room for others.

WHAT'S AVAILABLE

Sony is by far the biggest-selling brand. Other top-selling brands include Denon, JVC, Kenwood, Onkyo, Panasonic, Pioneer, RCA, and Yamaha. Most models now are digital, designed for the six-channel surround-sound formats encoded in most DVDs and some TV fare, such as high-definition (HD) programming. Here are the types you’ll see, from least to most expensive:

Stereo. Basic receivers accept the analog stereo signals from a tape deck, CD player, or turntable. They provide two channels that power a pair of stereo speakers. For a simple music setup, add a DVD or CD player to play CDs, or a cassette deck for tapes. For rudimentary home theater, add a TV and DVD player or VCR. Power typically runs 50 to 100 watts per channel.

Price range: $125 to $250.

Dolby Pro Logic. Dolby Pro Logic, Pro Logic II, and Pro Logic IIx are the analog home-theater surround-sound standard. Receivers that support it can take a Dolby-encoded two-channel stereo source from your TV, DVD player, or hi-fi VCR and output them to four to six speakers--three in front, and one to three in back. Power for Dolby Pro Logic models is typically 60 to 150 watts per channel.

Price range: $150 to $300 or more.

Dolby Digital. Currently the prevailing digital surround-sound standard, a Dolby Digital 5.1 receiver has a built-in decoder for six-channel audio capability--front left and right, front center, two rear with discrete wide-band signals, and a powered subwoofer for low-frequency, or bass, effects (that’s where the “.1” comes in). Dolby Digital is the sound format for most DVDs, HDTV, digital cable TV, and some satellite-TV broadcast systems. Newer versions of Dolby Digital, 6.1 and 7.1, add one or two back surround channels for a total of seven-channel and eight-channel sound, respectively. To take advantage of true surround-sound capability, you’ll need speakers that do a good job of reproducing full-spectrum sound. Receivers with digital decoding capability can also accept a signal that has been digitized, or sampled, at a given rate per second and converted to digital form. Dolby Digital is backward-compatible and supports earlier versions of Dolby such as Pro Logic. Power for Dolby Digital receivers is typically 75 to 150 watts per channel.

Price range: $200 to $500 or more.

DTS. A rival to Dolby Digital 5.1, Digital Theater Systems also offers six channels. It’s a less common form of digital surround sound that is used in some movie tracks. Both DTS and Dolby Digital are often found on the same receivers. Power for DTS models is typically 75 to 150 watts per channel.

Price range: $200 to $500 or more.

THX-certified. The high-end receivers that meet this quality standard include full support for Dolby Pro Logic, Dolby Digital, and DTS. THX Select is the standard for components designed for small and average-sized rooms; THX Ultra is for larger rooms. Power for THX models is typically 100 to 170 watts per channel.

Price range: $500 to $2,500 and up.

IMPORTANT FEATURES

Controls should be easy to use. Look for a front panel with displays and controls clearly labeled and grouped by function. Onscreen display lets you control the receiver via a TV screen, a squint-free alternative to using the receiver’s tiny LED or LCD display. Switched AC outlets (expect one or two) let you plug in other components and turn the whole system on and off with one button.

Remote controls are most useful when they have clear labels and buttons that light up for use in dim rooms. It’s best if the buttons have different shapes and are color-coded and grouped by function--a goal seldom achieved in receiver remotes. A learning remote can receive programming data for other devices via their remotes’ infrared signal; on some remotes, the necessary codes for other manufacturers’ devices are built-in.

Input/output jacks matter more on a receiver than on any other component of your home theater. Clear labeling, color-coding, and logical groupings of the many jacks on the rear panel can help avert glitches during setup such as reversed speaker polarities and mixed-up inputs and outputs. Input jacks situated on the front panel make for easy connections to camcorders, video games, MP3 players, digital cameras, MiniDisc players, and PDAs.

A stereo receiver will give you a few audio inputs and no video jacks. Digital-ready receivers with Dolby Pro Logic will have several types of video inputs, including composite and S-video and sometimes component-video. S-video and component-video jacks allow you to route signals from DVD players and other high-quality video sources through the receiver to the TV. Digital-ready receivers also have analog 5.1 audio inputs. These accept input from a DVD player with its own built-in Dolby Digital decoder, an outboard decoder, or other components with multichannel analog signals, such as a DVD-Audio or SACD player. This enables the receiver to convey up to six channels of sound or music to your speakers. Dolby Digital and DTS receivers have the most complete array of audio and video inputs, often with several of a given type to accommodate multiple components.

Tone controls adjust bass and treble, allowing you to correct room acoustics and satisfy your personal preferences. A graphic equalizer breaks the sound spectrum into three or more sections, giving you slightly more control over the full audio spectrum. Instead of tone controls, some receivers come with tone presets such as Jazz, Classical, or Rock, each accentuating a different frequency pattern; often you can craft your own styles.

DSP (digital signal processor) modes use a computer chip to duplicate the sound characteristics of a concert hall and other listening environments. A bass-boost switch amplifies the deepest sounds, and midnight mode reduces loud sounds and amplifies quiet ones in music or soundtracks.

Sometimes called “one touch,” a settings memory lets you store settings for each source to minimize differences in volume, tone, and other settings when switching between sources. A similar feature, loudness memory, is limited to volume settings alone.

Tape monitor lets you either listen to one source as you record a second on a tape deck or listen to the recording as it’s being made. Automatic radio tuning includes such features as seek (automatic searching for the next in-range station) and 20 to 40 presets to call up your favorite stations.

To catch stations too weak for the seek mode, most receivers also have a manual stepping knob or buttons, best in one-channel increments. But most models creep in half- or quarter-steps, meaning unnecessary button tapping to find the frequency you want. Direct tuning of frequencies lets you tune a radio station by entering its frequency on a keypad.

HOW TO CHOOSE

First, don’t assume that pricey brands outperform less costly ones. We’ve found fine performers at all prices. Points to consider:

How many devices do you want to connect? Even low-end receivers generally have enough video and audio inputs for a CD or DVD player, a VCR, and a cable box or satellite receiver. Mid- and high-priced models usually have more inputs, so you can connect additional devices, such as a camcorder, a personal video recorder, or a game system.

The number of inputs isn’t the only issue; the type also matters. Composite-video inputs, the most basic type, can be used with everything from an older VCR to a new DVD player. S-video and component-video inputs are used mostly by digital devices such as DVD players and satellite receivers. If you have such digital devices or may add them, get a receiver with a few S-video and/or component-video inputs. Both can provide better video quality than composite-video.

All these video inputs require a companion audio input. The basic left/right audio inputs can be used with almost any device to provide stereo sound. A turntable requires a phono input, which is available on fewer models than in years past.

To get multichannel sound from DVD players, digital-cable boxes, and satellite receivers, you generally use a digital-audio input. With this input, encoded multichannel sound is relayed on one cable to the receiver, which decodes it into separate channels. The input on the receiver must be the same type--either optical, the more common type, or coaxial--as the output on the other device. You usually must buy cables, about $10 and up, for digital-audio, S-video, and component-video connections.

What kind of sound do you want from movies? All new digital receivers support Dolby Digital and DTS, the surround-sound formats used on most movies. Both provide 5.1 channels. Most receivers also support Dolby Pro Logic, Pro Logic II, and sometimes Pro Logic IIx. If you want the latest type of surround sound, look for a receiver that supports Dolby Digital EX and DTS-ES. These offer 6.1 or 7.1 channels, subtly enhancing the rear surround. Fairly few movies using these formats are available, but offerings should increase.

What kind of music do you like? Any receiver can reproduce stereo from regular CDs. Most models have digital signal processing (DSP) modes that process a CD’s two channels to simulate a sound environment such as a concert hall. DSP modes feed a stereo signal through all the speakers to simulate surround. For multichannel music from SACD or DVD-Audio discs, get a receiver with 5.1 analog inputs.

How big is your room? Make sure a receiver has the oomph to provide adequate volume: at least 50 watts per channel in a typical 12-by-20-foot living room, or 85 watts for a 15-by-25-foot space. A huge room, plush furnishings, or a noisy setting all call for more power.

Is the receiver compatible with your speakers? If you like to blast music for hours on end, get a receiver rated to handle your front speakers’ impedance. Most receivers are rated for 6-ohm and 8-ohm speakers. If used with 4-ohm speakers, such a receiver could overheat and shut down.

Is it easy to use? Most receivers have legible displays and well-labeled function buttons. Some add an onscreen menu, which displays settings on your TV screen. An auto-calibration feature adjusts sound levels and balance to improve the surround effect. Models with a test-tone function for setting speaker levels help you balance the sound yourself.

Two tips: When deciding where to place your receiver, allow 4 inches or so of space behind it for cables and at least 2 inches on top for venting to prevent overheating. If setting up a home theater is more than you want to tackle, consider calling in a professional installer. Retailers often offer an installation service or can refer you to one.

Copyright © 2002-2006 Consumers Union of U.S., Inc.

For the latest information on this and many other products and services, visit http://www.ConsumerReports.org



How Does a CD Player Work

Today there is a wide range of CD players available for the consumer and choosing the right CD player can feel like an arduous task. Style, quality, design och technical solutions vary greatly between the different players. Some players are portable; others are included in larger sound systems. Some players can only handle one disc at the time; others can easily skip between 50 discs or more. Some CD players are very cheap, others are highly expensive. The list goes on and on. Regardless of which CD player you choose it will however consist of three basic parts that are found in all moderns CD players: a drive motor, a tracking device and a laser and lens system. Another thing that all CD players have in common is that they interpret data that has been stored in the form of elongated bumps on a CD (compact disc).

The drive motor in your CD player is the part that makes the disc spin round and round at a correct pace. The drive motor will gradually adjust the speed, since the correct pace depends on which part of the disc that is currently being interpreted. At some spots, the pace will be no higher than 200 rpm, while at other spots the pace needs to be increased up to 500 rpm. As the disc is rotated round and round by the drive motor, the tracking mechanism will adjust the laser assembly and make it possible for the laser and lens system to focus on the miniscule bumps where data has been stored. The laser is constantly being pushed from the centre and outward over the disc by the tracking mechanism.

The data interpreted by the laser and lens system has been stored in the form of elongated bumps on the surface of the CD. One single bump is very small and no wider than 0.5 microns. The height is greater than 125 nanometres and the length is 0.83 microns or slightly more. All these bumps are very neatly organised at the surface of the CD in the form of a 5 kilometre (3.5 miles) long spiral.

The CD itself is made up by several different layers, including a polycarbonate layer and an aluminium layer. When the laser tries to interpret data that has been stored on the CD, it will first penetrate the polycarbonate layer. The aluminium layer will then reflect the laser beam, and the light alterations will be detected by a special optoelectronic mechanism in the CD player. Since the bumps in which data has been stored reflects light in a different way compared to the areas between the bumps (commonly referred to as “lands”), the CD player can determine exactly which parts of the disc that is made up by bumps and which parts that are not.

If a CD is scratched or injured in any other way, it can be impossible for the CD player to interpret it. Sometimes only a minor part of the data will be skipped, but larger damages can render the entire CD useless. Always store your CD’s in a protective casing to decrease the risk of scratches. When you clean your CD’s, carefully move your hand from the centre and outwards to the edge rather than just swabbing around. Scratches that occur from a radial movement tend to be less damaging than other scratches.

The information you just read about CD players can be applied to most types of optic drives and can not only help you pick out a CD player for you home but also other types of optic drives such as car CD players and car DVD players.

Article Source: http://EzineArticles.com/?expert=William_Berg

The iPod Guide for Newbies and Not-so-Newbies

Unless you've been living under a rock you've at least heard the following terms: "iPod", "iPod Nano", "iPod Shuffle", "mp3 player", "iTunes", "podcast", "ripping".

While you may have heard the terms, you may not be 100% clear as to what these terms actually mean. Or, you may have seen people carrying around these small devices with headphones and wondered what exactly they were and what the big deal is.

So what are these devices and why are they so popular? This article is an overview of the mp3 player device, it's evolution, glossary of related terminology and options you have when buying an mp3 player, specifically an iPod.

Specifically, this article covers:

* Glossary of commonly-used terms (what is an iPod, iPod Nano, mp3 player, etc.)
* Comparison of the iPod to other audio-listening devices
* Other major brands of mp3 players on the market
* How can I use an iPod?
* The iPod's Battery and Battery life

Glossary of commonly-used terms (iPod, iPod Nano, mp3 player, etc.)

iPod a brandname of a portable media player that was created by a company called "Apple Computer".

The iPod was first launched in 1991.

The term iPod is also referred to as a digital audio player, which is basically a device that stores, organizes and plays digital music files (ex: mp3 files). It is more commonly referred to as an "MP3 player". The iPod can

The iPod can serve also as an external data storage device (i.e., files other than audio and video) but Apple has made a strategic decision to focus it's development and marketing on the iPod's simple UI (user interface) and ease of use rather than on it's technical capability.

CD players are one of the well-known precursors to digital audio players.

By far, the iPod is the best-selling digital audio player in the world and has gone mainstream which makes it one of the most popular consumer brands. I've seen a wide demographic use these things, from 8-year old kids to 80- year old grandmothers.

Digital Audio Player (DAP)

a name for a device that stores, organizes and plays digital music files (ex: mp3 files). It is more commonly referred to as an "MP3 player".

For the most part, DAPs are portable and use internal or replaceable batteries and headphones. Accessories are available that allow users to connect players to both car and home stereos. Some DAPs include features such as FM radio and microphones for voice recording. This technology continues to evolve at an ever-increasing rate. There are now DAPs that are available on sunglasses (Oakley's "Thump" model offers introduces the world’s first digital audio eyewear for a mere $229).

Portable Media Player (PMP)

a name for a versatile device which can store and play files that are in one or more media formats, such as video, audio and digital images / photos. Some models are capable of video and audio recording.

The best part is that it's portable, as it's name suggests.

mp3

a name for a type of 'audio file'. According to Wikipedia (which is a free online encyclopedia: http://en.wikipedia.org/), it's a digital audio format.

To get more info on this and to view the history of mp3 files, view the full Wikipedia definition by clicking on the following link: http://en.wikipedia.org/wiki/Mp3

mp3 player

another way to describe a DAP (see dap for definition).

Ripping

a termed used to describe the process of copying audio and/or video data from one media form, such as DVD (i.e., digital versatile disk) or CD (compact disk), to a hard disk.

Ripping can also refer to copying other media (referred to as "analog" media) such as VHS video or vinyl records to a digital format.

To conserve storage space, the copied data is usually encoded in a compressed format such as MP3, WMA or Ogg Vorbis for audio, or MPEG-2, MPEG-4, DivX, XviD or Ogg Theora for video.

When dealing with digital content, ripping has numerous uses and purposes, which includes:

Because digital camcorders can now write directly to a DVD, you then "rip" (i.e., extract) that content onto a computer where you store it and can edit, duplicate or back it up. You can rip (extract) songs from various CD's, albums, DVD's, etc. to your computer or DAP. You can then take all of that music and create your own playlists where you can organize your songs in many different ways (ex: rock / jazz / hip hop, etc.).

You can also rip those songs onto a DAP (PMP).

You use CD ripping software / programs to rip files from one device to another.

CD Ripping Programs / Software

also referred to as "CD ripper", "CD grabber" or "CD extractor". Basically, CD ripping is a software program that's designed to extract digital audio from a CD to a file or other output.

Examples include:

MS Windows Operating System:

o Exact Audio Copy: Free for private use. Many enthusiasts choose this CD ripping program because of its features and extraction quality in comparison to most other digital audio extraction programs.
o Amazing CD Ripper: (Windows XP and Vista). A powerful and user-friendly software for ripping audio CD tracks and saving them into audio formats (MP3 ,WAV ,WMA, etc. Priced from $19.95 USD.
o iTunes (Mac OS or Windows): iTunes is a digital media player application used to play and organize digital audio (music) and video files. iTunes also manages the content on iPods. In addition, Tunes can connect to Apple Computer's online iTunes Store where you can purchase digital music, music videos, TV shows, iPod games and even feature-length films

Linux Operating System:

o ABCDE (A Better CD Encoder): a CD ripper that's operated entirely from the command line.
o Grip: a cd player and cd ripping program. Free (a GNOME project).
o Sound Juicer: extracts audio from CDs and converts it into audio files that PCs or DAPs can play.

Podcast

a multimedia file that is distributed (paid or unpaid) over the Internet for playback on mobile devices and PC's. Podcasting is a way to listen to or watch radio-like programs or TV-like video feeds. You basically download a podcast feed into a DAP or PC and play it at your convenience.

It's important to repeat that you don't need a DAP to view / listen to a podcast. Your PC will work fine.

Many hours of podcasts can be stored on even low-capacity DAPs.

Flash Memory

a form of non-volatile computer memory that can be electrically erased and re-programmed. Non-volatile memory is computer memory that can retain the stored information even when not powered, like hard disks and floppy disks.

In addition to its use in DAPs, flash memory is also used in digital cameras (memory cards), mobile phones and USB flash drives (which are used for general storage and transfer of data between computers). It has also gained some popularity in the gaming mark

How the iPod (and DAPs in general) compare to other audio-listening devices:

Basically, the iPod is superior to all of the items listed below for the following reasons:

* CDs (Compact Discs):
o CDs can get scratched and skip, mp3 files don't
o mp3 players consume less power
o small size and, therefore, ease of portability - the smallest digital audio player is about 1/20th the size of a portable cd player.
o user interface - with CD's you must know what songs are on each track if trying to select a specific song whereas on some mp3 players you see the song title, artist and even album title on a list.
o higher storage capacity - you can store thousands of audio files on an mp3 player. CD players typically play 1 CD at a time.

* Cassette Tape (anyone still using these??):
o tapes get old and brittle
o tapes can jam in a cassette player

* Radio:
o No static
o Listen to only the songs you want to hear
o No commercials

Major brands of DAPs on the market: Even though the iPod is the most popular DAP on the market today, other brands do actually exist, such as:

* Apple Computer: iPod **
* Creative Technology: Creative NOMAD, MuVo, Creative Zen **
* Sony: Walkman, PlayStation Portable
* Toshiba: Gigabeat
* Microsoft: Zune **
* Samsung: Yepp
* Sandisk: Sansa
* Cowon: iAudio

** - Indicates that this DAP brand requires unique software in order to load content onto it.

How can I use an iPod? As time passes, new uses of DAPs can be found. You can now purchase iPods that allow you to:

* Listen to Music
* Listen to / View podcasts
* Play games
* View feature-length movies
* Watch home videos
* Image and other file storage
* Audio and video recording

The iPod's Battery and Battery Life The battery in all iPods is non-replaceable and is not designed to be removed or replaced by the user. Some users have been able to pry the case open to replace the battery, as some online stores sell them. Initially, Apple would not replace worn-out batteries. Their official policy was that the customer should buy a refurbished replacement iPod, at a cost almost equivalent to a brand new one. All lithium-ion batteries eventually lose capacity during their lifetime and this situation led to a small market for third-party battery replacement kits.

In 2003, Apple announced a battery replacement program. The initial cost was US$99, but it was eventually lowered to US$59 in 2005. One week later Apple offered an extended iPod warranty for US$59.

Third-party companies offer cheaper battery replacement kits that often use higher capacity batteries (ex: www.iPodBatteryDepot.com). For the iPod nano, soldering tools are needed because the battery is soldered onto the main board. On the fifth generation iPod, the battery is held onto the backplate with adhesive.

Apple states that their 30GB 5G iPod provides up to 14 hours of audio playback. This gives you can idea of how long your device will play tunes on a single charge...in the best-case scenario. However, for real-world use, many users report battery lives of less than 8 hours with the 30 GB video iPod.

If you've been wondering if you should take the leap and get one. I say the time is now!

Paula Wozniak is an IT Consultant and entrepreneur. Visit http://iPod.TopInfo4All.com for more information on iPod Models and comparisons.

Article Source: http://EzineArticles.com/?expert=Paula_Wozniak

CD Car Stereos

CD Car stereos have now become an indispensable accessory in cars. CD car stereos can play your favorite CDs, and these players are provided with a radio. Some of the CD car stereos are capable of playing MP3s. A CD car stereo system may consist of a stereo, a pair of speakers, satellite radios, subwoofers, amplifiers and navigation units. CD car stereos have many advantages. They allow you to access travel information such as congested areas easily and offer latest news and favorite sporting events.

There are several aspects to consider while buying a CD car stereo. One of the important features one should look for is the power of the stereo. The power output of the stereo is stated in watts, which decides the number of speakers it can run. For example, a car stereo listed as 4 x 52W can produce 52 watts of power and drive four speakers. Another important feature one should look for is a detachable front panel. This is an anti-theft device provided to ensure the security of your CD player. Nowadays, the detachable front panels come in stunning designs.

The main part of a CD Car stereo is the CD player. CD players should be compatible with both CD-R and CD-RW discs. CD changers are also important. They facilitate the user to hear up to 120 discs or more in whatever order they wish to program them or to skip from one track to another, or from one disc to another. The other audio products that you can buy to support your car stereo are in-built radio, speakers and subwoofer.

Car Stereos provides detailed information on Car Stereos, Car Stereo Systems, Car Stereo Installations, Car Stereo Speakers and more.

Article Source: http://EzineArticles.com/?expert=Jason_Gluckman