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03

JBL Power Series subwoofers 
are available in two different 
configurations: as a single 2-ohm
voice coil or as dual 2-ohm voice
coils. Depending on the amplifiers
you are using, you may use either 
single-voice coil or dual-voice coil
subwoofers in singles or multiples
to maximize the power available
from your amplifiers. To achieve 
the maximum amplifier output 
possible, you should design a
speaker system that provides 
the lowest impedance that 
your amplifier is rated to drive 
safely. When designing a 
subwoofer system, consider 
the following rules:

1. Don’t mix different subwoofer 

or enclosure types in the same
system (use all single-coil
woofers or all dual-coil woofers).

2. You may connect the coils of a

dual-voice coil woofer in series,
but we recommend that you
avoid connecting separate
woofers in series. Because the
amplifier-damping factor (the
amplifier’s ability to control 
the motion of the woofer) is
expressed as a ratio of terminal
impedance (the sum of speaker
impedance, wire resistance and
the D.C. resistance of any
crossover coil connected to the
woofer) to amplifier-output
impedance, connecting separate
woofers in series reduces the
damping factor of the amplifier 
to a value less than 1. This will
result in poor transient response.

3. You must use both coils of a

dual-voice coil woofer connected
either in series or in parallel.

4. Most amplifiers deliver exactly

the same amount of power
bridged into a 4-ohm load 
as they do running a 2-ohm 
stereo load.

To design a subwoofer system 
that maximizes available amplifier
power, keep the following rules 
in mind: 

1. The total system impedance of

woofers in parallel = 1/(1/w

1

+

1/w

2

+ 1/w

3

...), where w is the

nominal impedance of the
woofer. 

2. The total system impedance 

of voice coils (or woofers) in
series = w

1

+ w

2

+ w

3

...

The diagrams below and at right
show parallel and series speaker
connections.

Figure 1. Parallel connection

Figure 2. Series connection

POS ( + )

NEG ( – )

RED
STRIPE
POS ( + )

BLACK
STRIPE
NEG ( – )

POS ( + )

NEG ( – )

RED
STRIPE
POS ( + )

BLACK
STRIPE
NEG ( – )

Connecting Your Subwoofer to Your Amplifier 

JBL Power Series

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