A device that outputs a stronger signal than that which it received. In terms of audio, this signal is output over all or a portion of the audio range of 20 Hz to 20,000 Hz.

The audio signal fed into a system or the jack through which the audio signal is fed into a system.

An additional jack allowing the blending of a second audio signal into your speaker system.

A channel used to localize sound between the front left and front right speakers.

The frequency at which an audio signal starts to transfer from one output to another. For example, a crossover circuit would be used to filter out high frequencies from the signal sent to the subwoofer.

In terms of audio signals, the production or conversion of an analog signal into binary notation.

Audio signals which have been translated into binary notation.

An undesirable or unintentional change to an audio signal.

The manufacturer (and trademark) of audio noise reduction systems and other systems that improve the performance and fidelity of audio recording, transmission, and playback.

The standard implementation for Dolby AC3 encoding is a 5.1 channel arrangement: Five full bandwidth channels (left, center, right, left surround, right surround) plus a low frequency subwoofer channel. AC-3 is also known as Dolby Digital.

Used to record audio products while using Dolby AC-3 compression -- a high quality multi-channel digital audio code developed by Dolby that combines many channels as a single entity to enable much lower data rates than other types of multi-channel coders, yet, with no sacrifice in quality.

The actual loudspeaker, which vibrates to reproduce sound.

 A user-adjustable device or circuit that modifies the frequency response of a signal passing through it.

The range where a consistent or constant level (in decibels) is found after testing a speaker system with sine waves. Also, the statement of the results of this measurement, expressed in decibels of the change in amplitude within the constant frequency amplitude range, for example: +/- 2 dB from 60 Hz to 20 kHz. Generally, a wide range with low variation in amplitude in that range is desirable.

In Altec Lansing systems, the level of sine wave input signal (in Volts RMS) which, when applied to the input terminals of the amplifier of the system, will produce the targeted system output power (in Watts RMS) at the rated THD (Total Harmonic Distortion) %.

The jack or receptacle that receives and decodes digital audio signals transmitted through a fiber optic connection.

The greatest amount of wattage that a power amplifier can send to its loudspeaker.

 A loudspeaker unit (driver and surrounding cabinet) designed to operate with a separate subwoofer.

Measured in decibels, this is the difference between the signal strength a system reproduces compared to the strength or amplitude of its background noise.

Sound pressure level. The measurement of the amplitude (loudness) of sound. The unit of measurement is the decibel.

A separate loudspeaker unit that reproduces very low bass.

Total harmonic distortion. A measurement of the total of all the harmonics introduced by nonlinear (uneven levels of) distortion in a device. This measurement is indicated as a percentage of the strength of the fundamental (lowest level).

The technology for its speaker systems using a USB interface for audio signal transmission, as opposed to the traditional method of connection to a computer sound card. The chips that enabled reception of digital audio signaling through a USB port in conformance with Microsoft plug-and-play standards.

Short for Universal Serial Bus, USB is a standard for connecting computers to peripheral devices. It supports data transfer rates of 480 Mbps (480 million bits per second). Most new computers sold since 1999 come equipped with at least one USB port. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, keyboards and speaker systems, making USB a very flexible and appealing device interface.

The unit used to measure power.