JBL P1224 - Manual (Page 3)

JBL Power Series subwoofers
are available in two different
configurations: as dual 4-ohm voice
coils or as dual 2-ohm voice coils.
Depending on the amplifiers you are
using, you may use Power Series
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 dual 4-ohm
woofers or all dual 2-ohm
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.
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 1 1
+ + ...
w
1
w
2
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 to the right
show parallel and series
speaker connections.
Figure 1. Parallel connection
Figure 2. Series connection
3
CONNECTING YOUR SUBWOOFER TO YOUR AMPLIFIER
POS ( + ) NEG ( – )
POS ( + )
NEG ( – )
PARALLEL CONNECTION
SERIES CONNECTION
POS ( + )
NEG ( – )
POS ( + )
NEG ( – )
PARALLEL CONNECTION
SERIES CONNECTION