Monacor Carpower HPB-250 Manual De Instrucciones página 8

protect the newly laid 12 V cable against short circuit,
GB
insert in any case an additional 25 A fuse very near to
the battery (fig. 3).
To stabilize the operating voltage for the booster
and the resulting power increase as well as sound im-
provement, a power capacitor is recommended (e. g.
CPS-500 or CPS-1000 by CARPOWER).
6.1.3 Terminal GND (7)
Connect the ground terminal GND via a cable of a
cross section of min. 10 mm
CARPOWER) to the ground of the car or directly to the
negative terminal of the car battery. To avoid ground
loops, the ground of the car radio must be placed at the
point where also the booster is grounded.
6.2 Inputs
Connect both inputs INPUT (6) via cables with phono
connectors to the corresponding line outputs of the car
radio. If no line outputs are provided on the car radio,
alternatively connect the speaker outputs of the car
radio via a corresponding transformer (e. g. FGA-20 by
CARPOWER) to the booster inputs.
6.3 Speakers
Full range speakers, satellite speakers or bass
speakers resp. a subwoofer can be used. The greatest
output power is obtained with the connection of 2 Ω
speakers or a speaker group with a total impedance of
2 Ω per channel (e. g. two 4 Ω speakers or four 8 Ω
speakers connected in parallel). However, individual
4 Ω or 8 Ω speakers may also be connected whereby
the output power is reduced.
Important! All speakers must be connected with
2 poles, i. e. without common ground
connection.
When choosing suitable speakers, pay in
any case attention to their mechanical
and electrical capability in connection
with the booster power applied (also see
specifications of the booster page 9).
6.3.1 Bass speakers or subwoofer
As the low frequencies cannot be located by the hu-
man ear, subwoofers operate in mono operation. For
the operation with bass speakers or a subwoofer, set
the sliding switch (4) to position LP/MO.
Connections of the speakers to the terminals
SPEAKER (11):
L+ = + left bass speaker or + subwoofer*
L- = - left bass speaker or - subwoofer*
R+ = + right bass speaker
R- = - right bass speaker
* Due to the different delay times of the sound waves from
the subwoofer and from the remaining speakers to the
place of hearing it may be necessary to change the polarity
of the subwoofer, i. e. to reverse the positive and the nega-
tive connections.
Adjust with the control LP (2) the crossover frequency
for the bass speakers or for the subwoofer in the range
30 – 350 Hz (the lower the upper limit frequency, the
more difficult the acoustic location of a subwoofer; the
8
2 (e. g. CPC-100/SW by
higher the limit frequency, the more powerful the bass
support). As a guidance observe the specifications of
the speakers used.
6.3.2 Full range speakers
For the operation with full range speakers set the
sliding switch (4) to position ST, and connect the
speakers to the terminals SPEAKER (11):
L+ = + left speaker
L- = - left speaker
R+ = + right speaker
R- = - right speaker
6.3.3 Satellite speakers
For the operation with satellite speakers set the sliding
switch (4) to position HP/ST, and connect the speakers
to the terminals SPEAKER (11):
L+ = + left speaker
L- = - left speaker
R+ = + right speaker
R- = - right speaker
With the control HP (1) adjust the crossover frequency
for the satellite speakers in the range 30 – 350 Hz.
Approx. the same value as for the subwoofer should
be adjusted. Otherwise, if the crossover frequency is
too high, the level will fall in a certain frequency range,
or if the crossover frequency is too low, the level will
increase too much in the overlapping range of sub-
woofer and satellite speakers. In both cases there will
be a sound discolouration.
7 Level Matching
Prior to switching on, the complete wiring of the car
HiFi booster should be checked once again for cor-
rect connection. Only then connect the negative ter-
minal of the car battery again.
Hint: To keep the interfering radiation by the electric
system of the car as low as possible, the output
level of the signal source should be min. 1.5 V.
1) Set the control INPUT LEVEL (5) counter-clockwise
to minimum.
2) Adjust the signal source, e. g. the car radio, to the
max. volume which is not distorted (mainly to ap-
3
prox. / of the maximum).
4
3) Turn up the control INPUT LEVEL (5) so that just no
distortions occur.
4) If the booster is used for the extension of the exist-
ing car HiFi system, reduce the levels of the chan-
nels which are too high to match the volumes of all
channels with each other. (In case the total volume
should not reach the desired level, insert more
powerful boosters into the channels which are too
poor.)