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Built-in
Crossovers |
Often
used to keep high-frequencies from reaching a subwoofer.
A low-pass crossover allows only low frequencies to be
amplified. A high-pass crossover allows only high frequencies
to be amplified. It keeps low bass away from small speakers,
so they can play more efficiently.
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Bridged
Power |
Bridging
a car amplifier, combines the power output of two channels
into one channel. Bridging allows the car amplifier
to drive one speaker with more power than the amp could
produce for two speakers. Because of this high power output,
bridging is the best way to drive a single subwoofer.
Bridging an amplifier, combines the power output of two
channels into one channel.
Bridging allows the car amplifier to drive one speaker
with more power than the amp could produce for two speakers.
Because of this high power output, bridging is the best
way to drive a single subwoofer. If the amp is bridgeable,
the owner's manual will have directions that tell you
how.
Also, keep in mind that most car amplifiers need to see
a 4-ohm load when bridged to mono operation. If you want
to bridge your amp, you should use one 4-ohm speaker or,
if you prefer multiple woofers, wire two 8-ohm speakers
in parallel. (Consult your manual before operating your
amp in bridged mode.)
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Discrete
Output Devices |
There
are 2-3 basic types of output devices found on car audio
amplifiers 1). integrated circuits, 2) bipolar transistors,
or MOSFETs. An integrated circuit (or IC) is found only
on relatively low-wattage (20 watts RMS per channel or
less) car amplifiers called "bridged transformerless"
amps. An IC can not pass enough current to work on a more
powerful car amp and is not considered a discrete output
device. Bipolar transistors and MOSFETs are found on the
output stages of high powered car amplifiers. They are
fast enough and can handle enough current to send wattage
greater than 20 watts per channel to your speakers. Both
of these types of transistors are considered discrete
output devices. Usually there are two per channel, but
some amps feature as many as four per channel.
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Mono
Car Amplifiers |
Mono
(or monaural) car amplifiers are single channel amps,
well-suited for low-frequency applications. Mono car
amplifiers are stable to 2-ohms so you can connect them
safely to two 4-ohm woofers wired in parallel.
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MOSFET
|
(Metal
Oxide Semiconductor Field Effect Transistor) A type of
large output transistor used in the final stages of many
power amplifiers, and commonly found in most car amplifiers
today. Mosfet transistors are most often discrete devices,
used with smaller driver transistors and other devices,
to convert a small signal to a large one. They are
highly stable and efficient, compared to the bipolar types
that preceded them.
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Ohm |
The
measurement of electrical resistance and system impedance.
It is a measure of the degree to which electrons are limited
in both velocity and quantity in passing through a circuit.
In Impedance measurements, this takes into account, the
mechanical resistance inherent in the motion of transducers.
The standard is usually 4 ohms for car audio.
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Parametric
|
A
type of equalization that permits the center frequency,
the filter shape, and the amplitude of each band to be
varied. This gives you extremely precise control of the
tonal balance in your vehicle. (More versitile than graphic
equalizers)
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Preamp
output |
This
is the first stage of amplification in which the amplitude
of a very low-level audio signal is increased. The first
stage of amplification in which the amplitude of a very
low-level audio signal is increased.
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RMS
Power |
The
higher the RMS figure, the louder and cleaner your music
sounds. The RMS rating is the maximum the car amplifier
can put out all day long without distorting. The RMS rating
is very important.
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Peak
Power |
The
peak power rating tells you the maximum wattage a car
amplifier can deliver as a brief burst The RMS rating
is more important.
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Signal-to-Noise
Ratio |
A
measurement of noise level in a device compared to the
level of the signal. Higher numbers signify a greater
difference, which is better.
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Speaker
input |
Speaker
inputs let you connect an amp to a receiver that lacks
RCA preamp outputs.
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Total
Harmonic Distortion (THD) |
The
THD is usually expressed in dB. the ratio of (a) the sum
of the powers of all harmonic frequencies above the fundamental
frequency to (b) the power of the fundamental frequency
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Tri-Way
Output |
Car
Amplifier setup that powers a pair of stereo speakers
and one subwoofer simultaneously from the outputs of a
single 2-channel car amplifier. |
