Specifications

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Car Audio Reference Guide
Common Car Audio Math
The following section provides a simple and easy
to use reference for some of the more commonly
utilized mathematical formulas in the car audio
industry.
Ohm's Law
Ohm's Law was named after Georg Ohm, a
mathematician and physicist, born in 1789 and
lived to be 65 while living in Bavaria. Mr. Ohm
created the foundation for the basic units of
electricity which are now accepted as a standard
worldwide. Ohm's Law describes the relationship
between Power, Voltage, Current and Resistant
in AC, DC and RF (Radio Frequency) circuits and
is the foundation for all electronic circuit design.
The above chart provides all the common for-
mulas related to Ohm's Law.
Voltage (measured in Volts) is a measurement
of electrical potential between two points. One
Volt is the potential difference required to move
one coulomb of charge between two points in a
circuit while using one Joule of energy.
Current (measured in Amps) describes the rate of
electron flow in a circuit. One amp is equivalent
to the flow of one coulomb (6.25x108 electrons)
per second.
Resistance (measured in Ohms) is the unit of
resistance to current flow. One Ohm of resist-
ance will allow one Amp of current to pass when
a voltage of one Volt is applied to the circuit.
The Greek letter Omega ( ) is universally used to
describe Ohms.
Power (measured in Watts) is a measurement of
electrical work being done. One Watt is equiva-
lent to one Joule of energy being transferred or
dissipated in one second.
Joules is the Metric unit of energy (replaces
Calorie) and is equivalent to the amount of work
needed to apply a force of one Newton over a
distance of 1 Meter. 1 Calorie = 4.184 Joules
These units are used to describe the function of
any electrical circuit. Using the Ohm's Law wheel
on the left side of this page, you can calculate any
third unit when you know two of them.