Variable LP/HP Filter
Crossover components which provide adjustable cut-off frequencies, and levels.
VAS
Volume Acoustic Suspension. A volume of air in an enclosure that has the same resistance characteristic in acoustic terms as the speaker's suspension in mechanical terms. This is a factor taken into account when designing enclosures. It specifies the optimum internal volume of the enclosure.
Vas-Compliance
A measurement in liters or cubic feet of the volume of air that is equal to the compliance of the speaker's total suspension.
VCA (Voltage Controlled Amplifier)
An amplifier whose output is controlled by varying its voltage rather than by direct resistance (as with a potentiometer).
VCO (Voltage Controlled Oscillator)
An oscillator whose frequency output is controlled by varying its voltage rather than with a potentiometer.
VCF (Voltage Controlled Filter)
An audio filter whose effective frequency band is controlled by varying its voltage rather than with a potentiometer.
Vented (enclosure)
A type of speaker system also known as Tuned, Tuned Port, Ported, or Bass Reflex. They are basically Acoustic Suspension enclosures with the addition of a port or opening with a specific length. This allows a portion of the lower range to be coupled to the front wave produced by the woofer, in order to enhance the low frequency response. The portion of the range below the tuned point (Fb) is essentially a Free Air Driver that subjects the unloaded woofer to the possibility of severe, even catastrophic damage if the energy below this point is highly amplified. The best results for a vented speaker come when using woofers with a QTS in the range of .10 to .40.
Vented (speaker - see Bumped & Vented)
Vibrato
Expressive effect which producers a fluctuation of pitch. A rapid, slight variation in pitch in singing or playing some musical instruments, producing a stronger or richer tone. It is often used as an expressive device.
Voice Coil
The voice coil is the coil of wire fixed to a cylinder at the apex of the loudspeaker cone that interacts with a magnetic field. With the help of other speaker components, the voice coil is the active transducer that converts electrical signals from the amplifier or receiver into mechanical energy, which we hear as sound. The voice coil cylinder is the part of the speaker around which the voice coil is wound. More advanced speakers offer a heat-resistant voice coil to prolong speaker life.
Voltage
Voltage is an electrical charge, or potential difference, between two points, one being of higher relative voltage than the other is. A 1.5-volt 'C' battery has 1.5 volts of difference between the positive and negative terminals, for example. The unit of voltage is called the "volt," named after Allesandro Volta. Voltage can be thought of metaphorically as a pressure, such as water pressure in plumbing, that is available to initiate action or work. It, however, cannot do any work until a circuit is complete so that current (measured in amperes) can flow.
Voltage Drop
The amount of energy consumed when a device offers resistance in its circuit. The voltage (E) set up across a resistance (R) carrying a current (I). E=IR (Also see Volt).
Volume
Volume is obviously the most common word used to specify the control of relative loudness of sounds. It also pertains to the function on many electronic devices that is used to control the loudness.
Also - the measurment of the amount of space enclosed behind a speaker that functions as a resonance chamber.
VOM
Volt-Ohm-Meter, sometimes called a Volt-Ohm-Milliammeter. A multimeter that measures voltage, ohms, and milliamperes.
