Acoustics - the science or study of sound.

Amplifier - a component designed to increase the power of an applied signal.

Attenuation - the reduction of an electrical signal typically by some controlled amount.

Audio frequency - the acoustic spectrum of human gearing, generally regarded to be between 20 Hz and 20,000 Hz.

Baffle - a piece of solid material, usually wood, inside an enclosure used to direct or block the movement of sound.

Balance - equal signal strength provided to both left and right stereo channels.

Bandpass filter - an electronic circuit designed to pass only a range of frequencies between two specified frequencies.

Bass - the low end of the audio frequency spectrum: approximately 20 Hz to about 1000 Hz.

Battens - small strips of wood placed inside a speaker enclosure to reinforce its mating corners or to provide a mounting surface for front and back panels.

Capacitor - is a component that stores current that is available for instant delivery when bass notes demand the power.

Channel - the left or right signals of a stereo audio system.

Circuit - a complete path that allows electrical current from one terminal of a voltage source to the other terminal.

Clipping - a distortion cause by cutting off the peaks of audio signals. Clipping usually occurs in the amplifier when its input signal is too high or when the volume control is turned up too high.

Crossover - a component that will divide the range of frequencies your source unit supplies and sends them to different amplifiers or speakers.

Decibel (dB) - a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale.

An increase of 3 B is a doubling of electrical (or signal) power; an increase of 10 dB is a doubling of perceived loudness.

Distortion - any undesirable change in the characteristics of an audio signal.

DVC - Dual Voice Coil

Dynamic-range - the range of sound levels which a system can reproduce without distortion.

Dynamic range - the range of sounds, expressed in decibels (dB's), between the softest and loudest portions.

Equalizer (EQ) - a component that allows the adjustment of frequency response to tailor the sound to match personal preference, room acoustics and speaker enclosure design.

Farad - the basic unit of capacitance. A capacitor has a value of one farad when it can store one coulomb of charge with one volt across it.

It is recommended that for every 1,000 watts of total amplification you have - you install 1 farad of capacitor.

Filter - an electrical circuit designed to prevent or reduce the passage of certain frequencies.

Flat response - the faithful reproduction of an audio signal; specifically, variations in output level of less than one decibel (dB) above or below a median level over the audio spectrum.

Frequency - the number of sound waves that pass a specific point in one second; expressed in hertz (Hz).

Frequency response - the range of frequencies that are faithfully reproduced by a given speaker or audio system.

Full range - a speaker designed to produce all or most of the sound spectrum.

Hertz (Hz) - a unit of frequency equal to one cycle per second, named after German physicist Heinrich Rudolf Hertz (185794).

High-pass filter - an electronic circuit designed to pass only frequencies above a specified frequency.

Hiss - audio noise that sounds like air escaping from a tire.

Impeance - the opposition of a circuit or speaker to an alternating current.

Low-pass filter - an electronic circuit designed to pass only frequencies below a specified frequency.

Midrange - a speaker designed to reproduce the middle frequencies of the sound spectrum, generally between about 1,000 Hz to 4,000 Hz.

Noise - any unwanted sound.

Ohm - the unit used to measure resistance to the passage of an electric current, named after German physicist Georg Simon Ohm (17891854).

Ohm's law - a basic law of electric circuits. It states that the current (I) in amperes in a circuit is equal to the voltage (E) in volts divided by the resistance (R) in Ohms; thus, I=E/R.

Parallel - Wiring two speakers in parallel with the same impedance causes the impedance to decrease by one-half.

To wire your speakers in parallel: connect the positive (+) leads of both speakers to the amplifiers positive (+) terminal, and the negative (-) leads of both speakers to the amps negative (-) terminal.

Polarity - the orientation of magnetic or electric fields. The polarity of the incoming audio signal determines the direction of movement of the speaker cone.

Root mean square (RMS) - the (RMS) value of an alternating current produces the same heating effect in a circuit as the same value of the direct current.

Series - Wiring two speakers in series with the same impedance causes the impedance to double.

To wire your speakers in series: connect the positive (+) leads of one speaker to the amplifiers positive (+) terminal, connect the negative (-) leads of that speaker to the positive (+) lead of the second speaker, and connect the negative (-) lead of the second speaker to the amplifiers negative (-) terminal.

Signal - the desired portion of electrical information.

Signal-to-noise (S/N) - the ratio, expressed in dB, between the signal and noise.

Sound pressure level (SPL) - the loudness of the sound reproduced by a speaker or stereo system.

Subwoofer - a speaker designed to reproduce the very low frequencies of the sound spectrum, generally 20 Hz to 100 Hz.

SVC - Single Voice Coil

Total harmonic distortion (THD) - the percentage, in relation to a pure input signal, of harmonically derived frequencies introduced in the sound reproducing circuitry and hi-fi equipment (including the speakers).

Treble - the upper end of the audio spectrum, usually reproduced by a tweeter.

Tweeter - a speaker designed to reproduce the high frequencies, generally about 4,000 Hz to 20,000 Hz.

Watt - a unit of electrical power.

Woofer - a speaker designed to reproduce the low frequencies of the sound spectrum, generally 100 Hz to 1,000 Hz.

Almost all the definitions were taken from - Building Speaker Systems by: Gordon McComb, Master Publishing, Inc., 1988.