Download Seg VR 4-HIFI Technical information

Crossover distortion A small discontinuity (or, at least, nonlinearity) in a signal
when a transistor-based amplifier circuit switches from positive to negative
operation. This is addressed by Class A and Class A/B designs. Sometimes
called 'zero cross distortion'.
Crossover frequency The frequency at which a signal is handed from one
component to another. This applies in loudspeaker crossover networks and base
management systems.
Crossover network The set of components in a loudspeaker that divides up the
incoming signal, sending the bass to the woofer, the treble to the tweeter and,
sometimes, the middle frequencies to a midrange driver. The crossover network
uses resisters, capacitors and inductors (coils) to divide up the signal. Some
systems use active crossover networks. In such cases, the division is made
before the signal is amplified, so a separate amplifier is required for each driver.
Crosstalk Where a signal (particularly audio) leaks from one channel to another.
Thus a voice may be intended to be entirely in the left channel of a stereo
recording, but some portion of it appears in the right, dragging the apparent
position of the voice somewhat towards the centre of the sound stage. Normally
specified by the inverse of crosstalk: separation.
Current The quantity of electrical charge moving through a circuit over a given
time. The unit for current is amps or amperes.
D
DAC Digital to Analogue Converter. A component, circuit or device that converts
a digital signal to an analogue one. Compare ADC which does the reverse.
Damping factor A specification for power amplifiers which suggests the degree of
control that the amplifier exercises over a connected loudspeaker. It is the ratio
of the nominal impedance of the speaker (and is typically quoted for eight ohms) to
the internal impedance of the output stage of the amplifier. A high internal
impedance for the amplifier means that its frequency response will vary with realworld speakers since their impedance varies across their frequency range. It also
means that the driver, which wants to do its own thing under the influence of air,
its suspension and so forth, rather than what the signal is telling it to do, will face
a relatively high impedance to the voltage it is generating back into the amplifier.
Consequently it will be freer to do its own thing, rather than what the amplifier is
telling it to do. However the damping factor quoted for amplifiers does not take