Read JBL 408 GTi User Guide / Operation Manual online
Wiring
Use 2-conductor stranded type,
insulated wire to connect the 408 and
508GTi Woofer/Midrange and tweeter to
the included crossover, and the crossover
to the amplifier as shown in Figure K.
508GTi Woofer/Midrange and tweeter to
the included crossover, and the crossover
to the amplifier as shown in Figure K.
A minimum wire gauge of 18AWG is
recommended, with larger size suggested
for wire runs longer than 10 feet.
for wire runs longer than 10 feet.
The polarity (the positive / negative
orientation of the connections) for every
speaker and crossover to amplifier
connection must be consistent from left to
right channel to assure proper imaging and
optimum frequency response. This does not
mean that the woofer/midrange should
always be connected in the same polarity
as the tweeter however. It is possible, that
due to the difference in the distance the
sound travels from the woofer/midrange to
your ears compared to the distance from the
tweeters in a typical system, and the short
wavelengths of sound at the crossover
frequency, that a connection where the
tweeters are connected in reverse polarity
from the woofer/midrange drivers may
actually result in better sound. Because
there is no way to accurately predict this
before installation, we recommend that you
try the connection both ways, and leave it in
the polarity that gives the smoothest audible
transition between the woofer/midrange and
tweeter. When the tweeter and woofer/
midrange drivers are mounted close to
each other, the in-phase connection will
usually yield the best sound.
speaker and crossover to amplifier
connection must be consistent from left to
right channel to assure proper imaging and
optimum frequency response. This does not
mean that the woofer/midrange should
always be connected in the same polarity
as the tweeter however. It is possible, that
due to the difference in the distance the
sound travels from the woofer/midrange to
your ears compared to the distance from the
tweeters in a typical system, and the short
wavelengths of sound at the crossover
frequency, that a connection where the
tweeters are connected in reverse polarity
from the woofer/midrange drivers may
actually result in better sound. Because
there is no way to accurately predict this
before installation, we recommend that you
try the connection both ways, and leave it in
the polarity that gives the smoothest audible
transition between the woofer/midrange and
tweeter. When the tweeter and woofer/
midrange drivers are mounted close to
each other, the in-phase connection will
usually yield the best sound.
Crossover Tweeter Level
Adjustment
Adjustment
The Gti System Crossover allows you
to adjust the level of the GTi Systems
Tweeter. This adjustment is located under
the crossover cover. To remove this cover
simply press on the end of the cover
(as shown in Figure L) and lift off. The
adjustment of the tweeter level is done by
setting the switch on the crossover (see
Figure M) to the “0dB,” “–2dB” or “–4dB”
position. Set this switch in the position that
matches your personal preference. Both
crossovers should have this switch set in
the same position.
Tweeter. This adjustment is located under
the crossover cover. To remove this cover
simply press on the end of the cover
(as shown in Figure L) and lift off. The
adjustment of the tweeter level is done by
setting the switch on the crossover (see
Figure M) to the “0dB,” “–2dB” or “–4dB”
position. Set this switch in the position that
matches your personal preference. Both
crossovers should have this switch set in
the same position.
12
Figure K
LIFT
PRESS
Figure L
508 GTI Crossover
INPUT
WOOFER
TWEETER
INPUT
WOOFER
TWEETER
BLACK
(–)
RED
(+)
Connect to
White “W”
Terminal
Connect to
Red “W”
Terminal
408/508 MANUAL.QXP 7/17/98 11:21 AM Page 12
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