Specifications

184
Car Audio Reference Guide
Resistance Circuit Calculations
Two formulas are required for calculating the
net resistance of multiple resistive devices wired
together.
Series Circuits
When multiple devices are wired in Series then
use the following formula:
Rtotal = R1 + R2 + R3 + R...
The total resistance is the sum of each resist-
ance.
Example:
A circuit with four 2-Ohm loads wired in Series
has a total resistance of: 2 + 2 + 2 + 2 = 8 Ohms
Parallel Circuits
When multiple resistive devices are wired in par-
allel, the formula is slightly more complex:
1/Rtotal = 1/R1 + 1/R2 + 1/R3 + 1/R...
This is know as calculating the sum of reciprocal
resistances.
Example:
A circuit with four 8-Ohm loads wired
in parallel has a total resistance of:
1 / ((1/8)+(1/8)+(1/8)+(1/8) = 2 Ohms
Circuit wiring Descriptions
So how do you wire a device (most commonly
a speaker) in series or parallel? The drawings
below described each method.
Series
The example above shows a Dual Voice Coil
subwoofer with both voice coils wired in series.
If this were a PXW1051 with dual 2 Ohm voice
coils, the net load would be 4 Ohms. If this was
a PXW1051, with dual 4 Ohm voice coils, the net
load would be 8 Ohms.
Parallel
The example above shows a Dual Voice Coil
subwoofer with both voice coils wired in paral-
lel. The two positive connections are both con-
nected to the positive terminal of the amplifier
and both negative connections are connected to
the negative terminal of the amplifier. If this were
a PXW1051 with dual 2 Ohm voice coils, the load
would be 1 Ohm, if this was a PXW1052 with
duial 4 Ohm voice coils the net load would be 2
Ohms.
Series Parallel
This example is more complex. When multiple
drivers are in use, you can wire each driver using
series or parallel, then wire the set of drivers in
either series or parallel. When multiple drivers
are being used, Clarion recommends wiring each
speaker in series with the other. In the unlikely
event of a speaker failure, this provides the most
protection against further damage.
In this example, if we are using two PXW1051
subwoofers, the net load would be 2 Ohms. If
these were PXW1052 subwoofer, the load would