Car Audio Dictionary:
A: Attenuation, loss of dB. AC (Alternating Current): An electrical current that intermittently changes in amplitude and direction. Acoustic
Fiberglass: Thin fiberglass material used as damping material inside speaker enclosures.
Acoustics: The study of sound.
Air Gap: The space separating the top plate and the pole piece. This is where the voice coil sits.
Alignment: A class of enclosure parameters that gives optimum performance for a woofer with a given value of Q.
Alpha: In sealed enclosure designs, the ratio of Vas to Vb, where Vb is the volume of the box you will build.
Alternator: A device that is turned by a motor to produce AC voltage, which is then rectified (turned into DC) and used to supply voltage to the vehicle's electrical system.
Ampere (A): The unit of measurement for electrical current in coulombs per second. There is one ampere in a circuit that has a one ohm resistance when one volt is applied to the circuit.
Amplifier: An electrical circuit designed to boost the current, voltage, or power of an applied signal.
Amplitude: The relative strength (usually voltage of a signal). Amplitude can be expressed as either a negative or positive number, depending on the signals being compared.
Attenuation: The reduction, typically by some controlled amount, of an electrical signal.
Audio Frequency: The acoustic spectrum of human hearing, generally regarded to be between 20 Hz and 20 kHz. B: Magnet flux density in gap.
Baffle: A board or other plane surface used to mount a loudspeaker.
Balance: Same strength is provided to both left and right stereo channels.
Bandwidth: The range of frequencies covered by a driver or a network (crossover).
Band-Pass Enclosure: Type of enclosure used for subwoofers where the driver is completely inside the enclosure and all of the output emerges through a port(s) on one of the sides. They are challenging to calculate for optimum performance.
Band-Pass Filter: An electric circuit created to pass only a certain range of frequencies.
Basket: The metal frame of a speaker.
Bass Blockers: First order high-pass crossover (non-polarized capacitors), usually used on midbass or dash speakers to keep them from trying to reproduce deep bass that could damage them at high playing levels.
Bass Frequencies (Low Frequencies): The low end of the audio frequency spectrum. There are no real frequencies where bass is categorized, but it ranges from approximately below 20 Hz to 400 Hz.
Bi-amping: Means that instead of driving a speaker full-range with a single channel of amplification, through one set of speaker cables, you actually connect two sets of cables, with each set driven by a separate amplifier, or separate channels of a multi-channel amplifier. This way, low frequencies and high frequencies each receive dedicated amplification.
