System Design Using the
GTS100
Speakers
When used in the non-bridged mode,
the GTS100 can easily drive 2 ohm
speaker loads. When only one speaker
is connected to each channel, virtually
any common speaker may be used.
When two speakers are connected in
parallel to a given channel, each speaker
must have a minimum impedance of at
least 4 ohms to ensure that the com-
bined load does not drop below 2 ohms.
Although the amplifier will not be dam-
aged, load impedances lower than 2
ohms will eventually cause the amplifier
to overheat, activating the protection
circuits and causing the unit to shut off
until it cools down sufficiently.
6
(+)
(-)
(+)
(-)
Parallel Wiring
Series Wiring
2 Ohms
Nominal
Impedance
8 Ohms
Nominal
Impedance
4
Ohms
4
Ohms
4
Ohms
4
Ohms
When the GTS100 is in bridged mode,
the combined impedance of the speaker
(or speakers) connected to the bridged
channel should be at least 4 ohms. As
in the example above, sustained opera-
tion of the GTS100 in bridged mode
with less than 4-ohms will likely cause
overheating. If monaural operation is
desired, and two 4-ohm speakers are
used, it is best to connect each speaker
to an individual amplifier channel and
use the “L+R” mode on the input-mode
switch to provide monaural operation.
The GTS100 must not be used with
speakers that have either one of their
input terminals wired to the frame of
the speaker or to the chassis of the
vehicle.
Signal Sources
The low level preamp outputs of any
radio/tape deck, CD player or preamp/
equalizer so equipped can drive the
GTS100. The Gain control of the
GTS100 is used to match the amplifier
to the output voltage of the source.
This matching is important to keep
noise low and is explained in the Gain
Adjustments section of this manual
(page 20).
Thanks to Universal Interface circuitry,
the GTS100 can also be connected to
power amplifiers, radios or equalizers
that are equipped with only speaker
outputs by connecting them through the
speaker level input connector. Inside
the GTS100, the speaker-level and
preamp-level inputs are connected
through a mixing circuit, which allows
them to be used simultaneously.
Therefore a low level source, such as
a CD player equipped with preamp
JBL 1394 Manual 7/17/98 11:49 AM Page 6