Two Channel Audio (Stereo)
Two channel audio, stereo, 2.0 audio or any audio system comprised of two 'channel's of audio data is the term coined for most music systems.
Conventionally, a stereo is made up of a source (be it CD, a record, an iPod, computer or one of many other devices), a two channel amplifier, and two speakers (a pair). Stereo gets it's name from Stereophonic, which is a method of sound reproduction that creates an illusion of multi-directional audible perspective. By using two speakers, the recording and mastering engineers are able to create 'stereo imaging'. A technique that allows the stereo system to imitate certain sounds coming from certain directions.
For an example, by playing a saxophone recording solely on the left hand speaker, it would sound as though the saxophonist is playing to the left of centre stage.
A drummer could be played solely through the right speaker, as if audibly appearing to the right. The singer's voice can be played at equal levels through both speakers to appear as though his voice is coming from the centre of the stage. By tweaking these parameters, the engineers are able to create a full sound stage, and also create audible effects, such as albums like Dark Side of the Moon by Pink Floyd.
Multi Channel and 5.1
For more information on multichannel audio, please read this glossary entry.
Jumping to surround sound amplifiers, these essentially accomplish an extended version of what a stereo amp does. By using a 'centre' channel as well as a left and right, it can more accurately depict and centre focused sound stage.
Adding a surround left and right, situated generally slightly behind the listener, the sound stage can be extended to behind the music / movie listener. This is where you start to get the different formats. A single channel is called Mono, or 1.0 audio. Two channel, aka 2.0. 5 channel (5.0) and so on. What's the point(.1)?
Commonly, you will see a .1 or .2 added on. These are what's known as sub channels for
subwoofers producing low frequency sound. More commonly for home theatre and five or more channels, however quite commonly now, as the appeal of smaller speakers grow, a lot of people are using subwoofers for stereo listening, say as a 2.1 or 2.2 configuration.
Two channel audio (stereo) Two channel audio, or stereo, is a format that a good 99% of the music you listen to is recorded in. For playback, it is generally listened through a pair of speakers or headphones. read more
5.1 Channel Audio The most common surround sound setup. This includes a left, center and right speaker, two surround speakers and a subwoofer. read more
Asynchronous DAC A device which converts a digital audio signal to an analogue one. Often used for playing digital music through a traditional stereo. Asynchronous means that the DAC controls all of the timing information. read more
Atmos Dolby Atmos is the latest and greatest surround format from Dolby. It is based on a completely immersive speaker setup with overhead speakers. read more
Audio Resolution The resolution is the ability to accurately reproduce the small details of the sound. In digital audio it specifically refers to the bit depth, which refers to how small each digital increment can be. read more
Bass The low frequency part of a sound. This refers to everything from a low loud rumble through to a particularly deep voice. read more
Bi-Amp Bi-Amp means using two amplifiers to power your speakers. This can be either using a separate amplifier for the low and high frequencies, or a separate amplifier for each speaker. read more
Bi-Wire This refers to wiring separately for the low and high frequency drivers in your speakers. This requires two seperate sets of speaker cables but can improve the performance of some speakers. read more
Bitrate Bit-rate is the number of digital samples taken every second. This allows a digital signal to accurately track high frequency sounds. read more
Bluetooth Apt-X Buetooth Apt-X is a lossless transmission format for bluetooth audio. In good reception, the full resolution of CD is transmitted. read more
Bluetooth SBC SBC is the default codec used for audio over bluetooth. It is a lossy codec, which means that not all of the data from the music is transferred perfectly. The quality of SBC is easily surpassed by the newer apt-X bluetooth. read more
Bridged Power Bridging an amplifier combines the power output of two channels into one channel. There are two different ways of achieving this. read more
Clamping Voltage Clamping Voltage is the voltage above which a surge protector starts working, literally "clamping' the voltage and protecting from spikes above this number. read more
Class D Amplification A Class D amplifier is an integrated or power amplifier using a particular method for amplifying a signal. Class D is beneficial as it features a very, very efficient design compared to conventional amplifiers. read more
Clipping Clipping is a strong distortion caused when your amplifier exceeds it's power output. It can severely damage speakers. read more
Coaxial Cable (RG6) A cable with an inner core and an outer shield. Most commonly used in aerial systems due to it's low cost and high reliability. read more
Compression (Audio Files) A process of temporarily or permanently reducing audio data for more efficient storage or transmission. Common formats include MP3 and FLAC read more
Crossover The crossover is the part of a speaker system that seperates out the low and high frequencies and divides them to different speaker or drivers. It can either be in the speaker, receiver or both. read more
DAB DAB is a standard for digital radio transmission. Although it is very popular overseas, it is yet to catch on in a meaningful way in New Zealand. read more
Damping Factor Damping factor is a term used in regards to how quickly an amplifier can stop a speaker's driver from moving, when no signal is present. read more
Dark Chip A comparison of the different technologies available for DLP based projectors including DC, DC2, DC3, DC4 and including both 0.65" and 0.95" chipsets read more
DLNA A standard set to enable audio and video streaming between networked devices. Theoretically this should allow your device to connect relatively painlessly read more
Dolby Digital Dolby digital is one of the most popular formats for surround sound. It's used by DVD's and Netflix. It is a compressed format, so the newer uncompressed formats sound better. read more
Dolby Pro Logic Dolby's system for upsampling audio from a two channel source to a surround sound system. It is of basic quality and has since been trumped by newer standards. read more
Driver A driver is an individual transducer, which is the part of the speaker that turns electricity into actual sound. read more
DSD - Direct Stream Digital DSD stands for Direct Stream Digital, a method of encoding analog sound as digital informaton. It differs radically from a traditional CD; where a CD is 44,100 samples of 16 bits per second, DSD is 2,822,400 1 bit samples per second. read more
DSP DSP refers to algorithms which alter sound digitally. This can massively improve the sound with much less error that similar analogue methods. read more
DTS DTS is a company which licences codecs. They dominate the physical disc market with DTS5.1 and DTS Master Audio. read more
DTS Play-Fi A simple glossary article describing: What is DTS Play Fi? How do I stream music throughout my house and related questions. read more
DVD-Audio DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering high-fidelity audio content on a DVD. It contains no video information. It is an alternative to SACD, though neither has really gained wide spread acceptance. read more
Dynamic Range Dynamic Range is the difference between the quietest sounds on a recording to the loudest. This defines a systems ability to go smoothly from a whisper to a roar. read more
Electrostatic Speaker An Electrostatic Speaker is a driver made of a thin, electrically charged film. This frees it of traditional cabinets for a clear, focused, colour free sound. There are physical trade off's with this approach. read more
FLAC FLAC is a common codec for storing Music digitally. With a smaller file size but without any loss of quality. read more
Frequency Response The range of frequencies which a speaker is capable of reproducing. Low frequencies that we can hear start at 20Hz and go through to 20,000Hz read more
1080P Full HD 1080P is a set of standards for high resolution video. It typically involves 1080 lines of vertical resolution. It is the current resolution of most Blu-Ray Disc's read more
HDMI HDMI is short for High Definition Media Interface, a standard used for connecting many Digital Audio and Video Devices. It is the only way to get the best quality audio and video in consumer products. read more
Integrated Amplifier An Integrated Amplifier, Integrated Amp or just 'Amplifier' is what powers your speakers, and amplified the signal it is given, be it a CD player, Streamer, Turntable etc read more
Jitter Jitter is a common source of poor sound in digital systems. It is one of the main targets of improvement in nicer D/A converters. read more
kbps kbps stands for kilo bytes per second. It refers to how aggressively compressed music is. In general, the smaller the number the smaller the file size and the worse the sound. read more
Line Level Line Level is a standard volume for analogue sources to be plugged into an amplifier when using a standard RCA connector. read more
Lossless Compression Lossless compression means temporarily reducing the file size of an audio signal. This means you can fit more files on your hard drive without reducing audio quality. read more
MDC MDC is NAD's Modular Design Construction. It gives many of their new amplifiers the ability to be upgraded by adding a module to increase functionality; hence the name. read more
Media Server A device used to store digital media files as well as distribute them to devices throughout the local network. read more
Musiccast Yamaha MusicCast is Yamaha's system for easily controlling music and sound throughout your home from your iPad or Android device. Based on simple app control of their entire suite of products from mini systems through to home theater amplifiers. read more
NFC NFC is part of the Bluetooth protocol for easy pairing. read more
Phase Cancellation Phase cancellation is a phenomenon where a sound wave can be 'cancelled out' to varying degrees by an identical wave that is out of phase read more
Power Amplifier A power amplifier or power amp is the main 'driving' stage of an integrated amplifier or pre and power amp combo. It does exactly what it's prefix suggests which is powers the speaker, by pushing, or pulling the driver in and out to create sound. read more
Preamplifier The preamp's duty is to change the input as well as things like volume, balance, tone controls and any other adjustments. read more
SACD Super Audio CD (SACD) is a high-resolution CD for audio storage. Although the sound quality is very good, it is a difficult format to work with, so never gained widespread popularity outside audiophile circles. read more
Sonos Trueplay Sonos Trueplay takes advantage of the microphones in your iOS devices to perform a room correction for your Sonos units. read more
Sub Woofer A speaker designed to produce low frequency sound (sub bass). Generally this is done by using a large, single driver. read more
Tweeter A rundown on what a tweeter is, and what is does as well as the different types. read more
Woofer A Woofer is generally the larger driver in a loudspeaker and is used to produce bass or low frequency sound. This can generally be from anywhere between 200-1000Hz and below. read more