The GT5-12 subwoofer has a single
4-ohm voice coil. Be sure to consider
your amplifier’s optimum load when
designing a subwoofer system. Many
bridgeable 2-channel amplifiers are
optimized to drive a single 4-ohm
woofer in bridged mode. If you will
use multiple woofers, be sure to
configure them to extract all the
power available from your amplifier.
When designing a subwoofer system,
consider the following rules:
1. Do not mix different subwoofers
or enclosure types in the same
system. Subwoofers being used in
the same enclosure or powered
by the same amplifier should
be identical models. Mismatched
woofers and enclosures can
result in poor system performance.
2. Most amplifiers deliver exactly
the same amount of power
bridged into a 4-ohm load
as they do driving a 2-ohm
stereo load.
3. If you are designing a multiple-
woofer system, be sure to configure
the woofers so that they each
receive the same amount of
power from the amplifier. Never
connect two identical woofers in
series and then connect that pair
to another woofer in parallel. If
your system will include an odd
number of woofers, be sure to
connect
all
the woofers in
either
series or parallel according to
the rules that follow, in order to
maximize the power available
from your amplifier:
a. The total system impedance
of voice coils (or woofers) in
series can be calculated using
the formula:
Impedance = w
1
+ w
2
+ w
3
...
b. The total system impedance
of woofers in parallel can be
calculated using the formula:
Impedance =
1
1
+
1
+
1 ...
w
1
w
2
w
3
where w is the nominal
impedance of the woofer.
The diagrams at right show series
and parallel speaker connections.
Figure 1. Connecting two woofers
in series to the amplifier (8 ohms)
Figure 2. Connecting two woofers in
parallel to the amplifier (2 ohms)
3
3
CONNECTING YOUR SUBWOOFER TO YOUR AMPLIFIER
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
Series connection of two woofers (8 ohms)
Parallel Connection of two woofers (2 ohms)
Connection of single woofer (4 ohms)
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
Series connection of two woofers (8 ohms)
Parallel Connection of two woofers (2 ohms)
Connection of single woofer (4 ohms)
