Inductance. The property of an electrical circuit by which a varying current in it produces a varying magnetic field that introduces voltages in the same circuit or in a nearby circuit. It is measured in henrys.
Inductor. A device designed primarily to introduce induc- tance into an electrical circuit. Sometimes called a choke or coil.
Linearity. The extent to which any signal handling process is accomplished without amplitude distortion.
Midrange. The middle frequencies where the ear is the most sensitive.
Passive crossover. Uses no active components (transistors, IC’s, tubes) and needs no power supply (AC, DC, battery) to operate. The crossover in a typical loudspeaker is of the passive variety. Passive crossovers consist of capacitors, inductors and resistors.
Phase. The amount by which one sine wave leads or lags a second wave of the same frequency. The difference is described by the term phase angle. Sine waves in phase reinforce each other; those out of phase cancel.
Pink noise. A random noise used in measurements, as it has the same amount of energy in each octave.
Polarity. The condition of being positive or negative with respect to some reference point or object.
RMS. Abbreviation for root mean square. The effective value of a given waveform is its RMS value. Acoustic power is proportional to the square of the RMS sound pressure.
Resistance. That property of a conductor by which it opposes the flow of electric current, resulting in the generation of heat in the conducting material, usually expressed in ohms.
Resistor. A device used in a circuit to provide resistance.
Resonance. The effect produced when the natural vibra- tion frequency of a body is greatly amplified by reinforcing vibrations at the same or nearly the same frequency from another body.
Sensitivity. The volume of sound delivered for a given electrical input.
Stator. The fixed part forming the reference for the moving diaphragm in a planar speaker.
THD. The abbreviation for total harmonic distortion. (See Distortion)
TIM. The abbreviation for transient intermodulation distortion.
Transducer. Any of various devices that transmit energy from one system to another, sometimes one that converts the energy in form. Loudspeaker transducers convert elec- trical energy into mechanical motion.
Transient. Applies to that which lasts or stays but a short time. A change from one
Tweeter. A small drive unit designed to reproduce only high frequencies.
Wavelength. The distance measured in the direction of progression of a wave, from any given point characterized by the same phase.
White noise. A random noise used in measurements, as it has the same amount of energy at each frequency.
Woofer. A drive unit operating in the bass frequencies only. Drive units in