Watts what in audio!

Ampere: The fundamental unit used to measure electric current.

Amplifier: A component that boosts the level of an input signal by increasing its amplitude.

Amplitude: Magnitude or size of the signal voltage or current.

Bandwidth: The range of frequencies a component operates within.

Bass: A low-pitched sound or tone, often under 200 Hz.

Channel: A separate signal path, in reference to components and systems.

Clipping: Audible distortion that occurs when an amplifier is over-loaded; when current or voltage is increased beyond its limits.

Decibel or dB: Unit that measures the loudness of sound.

Diffusor: A device used to preserve sound energy by reflecting it evenly in multiple directions, as opposed to a flat surface, which focuses it in a single direction.

Digital audio player: A device that stores, organizes and plays digital music files.

Dolby Digital Sound System: 5.1-channel home theatre sound system, which comprises left and right surround speakers; right, left, front and centre speakers; and a low-frequency effects channel.

Equaliser: Electronic filters designed to alter the frequency balance of an audio signal. It may be graphic, parametric, or a combination of both.

Fidelity: The accuracy with which systems reproduce the sound or image of the input signal.

Filter: A device that removes unwanted frequencies or noise from a signal.

Frequency: The number of complete cycles that a sound wave goes through in each second expressed in Hertz or Hz.

Frequency response: The accuracy of sound reproduction measured in decibels (dB) ranging between 20 to 20,000 Hz.

Full-range speakers: A speaker designed to reproduce the full range (20 Hz to 20 kHz) of audio frequencies.

Home theatre system: An audio/video system designed and configured for the presentation of high-quality images and sound at home. Most home theatre systems include a DVD/VCR, stereo television or HDTV, receiver and DVD.

MIDI files (Musical Instrument Digital Interface): A standard protocol for interchanging musical information between musical instruments, synthesizers and computers.

Mid-range speaker: A loud speaker that normally produces frequency ranging between 300 to 5,000 Hertz.

MP3: A file extension for MPEG-1 Audio Layer-3. It is a compression scheme used to transfer audio files via the Internet and store in portable players and digital audio servers.

Mono: Sound transmission or recording or reproduction over a single channel.

SACD (Super Audio CD): A read-only optical audio disc that provides higher fidelity audio reproduction than the compact disc.

Satellite radio: A digital radio that receives signal broadcast by the communication satellite covering a much wider geographical range than normal radio signal.

Stereo: Reproducer in which two microphones feed two or more loudspeakers to give a three-dimensional effect to the sound.

Subwoofer/woofer: A speaker designed exclusively for low-frequency reproduction. They are designed to reproduce very low bass frequencies, usually those below about 80 Hz.

Surround sound: A sound system extracted from the stereo signal sent to smaller rear or side speakers used in a home theatres. It is designed to place the listener in the centre of the sound.

Tuner: An electronic device used to tune acoustic or electronic instruments to standard pitch.

Tweeter: A speaker driver designed to reproduce high frequencies often combined with a woofer or a woofer and mid-range system.

Voltage: Electrical pressure that forces current to flow expressed in volts.

Wattage: The unit of power used to rate the output of audio amplifiers.