Acoustic suspension A type of speaker enclosure that uses a sealed box to provide tight, accurate bass response. It gives up some efficiency to provide bass that is more accurate and controlled, so compared to a bass reflex design, it may require more amplifier power to play at the same volume level.
Active Containing tubes or transistors that require an external source of power, and typically provide amplification.
Active Crossover A powered electronic network that divides up the frequency constituents of an audio signal (bass, midrange, and treble) before it is amplified and sent to the various drivers in a speaker system. While active crossovers are often contained within sub-woofer enclosures along with the bass driver(s), those that work with multiway systems may also be outboard mounted.
Amp Short for amplifier, and also the abbreviation of Ampere, the unit for electrical current. Electrical current is sent through the speaker input terminals to make the speaker produce sound. A good 120 watt amplifier can momentarily send a peak current of 80 amps through a speaker, which will really rattle your windows; maximum sustained average current at 120 watts, which is also very loud, is around 4 amps.
Amplifier A device (sometimes called an "amp") for boosting the amplitude of a given electrical signal; ideally, without affecting its quality.
Analog Signal The exact electrical or mechanical replica of any particular audio or video input to a system. Any signal originally produced by non-digital recording equipment, even though the finished item may be a digital audio disc or a digitally compressed video signal. Note that no matter what the recording medium, the sound or picture we ultimately experience is analog. We live in a subjectively analog world.
Audiophile A person who has an enduring interest in audio.
Home Audio Glossary of Terms created to inform and educate individuals interested in creating a home theater environment. This page defines all audio terms beginning in the letter A, such as but not limited to Acoustic suspension, active, active crossover, amp, amplifier, audiophile.