Level Matching - Monacor CARPOWER HPB-350 Mounting Instructions

insert in any case an additional 40 A fuse very near to
GB
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 (8)
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 (7) 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 or satellite speakers and bass
speakers or 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
Connect a 2 Ω subwoofer (or two 4 Ω or four 8 Ω bass
speakers in parallel) to the terminals MONO SUB
CHANNELS (13) to support the main speakers in the
low pass range. As the low frequencies cannot be
located by the human ear, the bass channel works in
mono operation.
Important! The terminals MON SUB CHANNEL 1
and MONO SUB CHANNEL 2 (13) of the
bass channel are connected in parallel,
i. e. the total impedance of the speakers
connected to these terminals must not be
lower than 2 Ω.
Connections of the speakers to the lower terminal row
MONO SUB CHANNELS (13):
1+ = + left bass speaker or + subwoofer*
1- = - left bass speaker or - subwoofer*
2+ = + right bass speaker
2- = - 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
8
2 (e. g. CPC-100/SW by
of the subwoofer, i. e. to reverse the positive and the nega-
tive connections.
Adjust with the control LP SUB (1) the crossover fre-
quency for the bass speakers or for the subwoofer in
the range 30 – 350 Hz (the lower the upper limit fre-
quency, the more difficult the acoustic location of a
subwoofer; the 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 XOVER (4) to position OUT, and connect
the speakers to the upper terminal row (12):
CHANNEL 1 L+ = + left speaker
CHANNEL 1 L- = - left speaker
CHANNEL 2 R+ = + right speaker
CHANNEL 2 R- = - right speaker
6.3.3 Satellite speakers
For the operation with satellite speakers set the sliding
switch XOVER (4) to position IN, and connect the
speakers to the upper terminal row (12):
CHANNEL 1 L+ = + left satellite speaker
CHANNEL 1 L- = - left satellite speaker
CHANNEL 2 R+ = + right satellite speaker
CHANNEL 2 R- = - right satellite speaker
With the control HP L&R (5) adjust the crossover fre-
quency 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 fre-
quency is too high, the level will fall in a certain fre-
quency range, or if the crossover frequency is too low,
the level will increase too much in the overlapping
range of subwoofer 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 two controls INPUT LEVEL (2 + 6) counter-
clockwise to minimum.
2) Adjust the signal source, e. g. the car radio, to the
max. volume which is not distorted (e. g.
maximum).
3) Turn up the right control INPUT LEVEL (6) so that
just no distortions occur.
4) With the left control INPUT LEVEL (2) adjust the
subwoofer or the bass speakers to a natural or a
deliberately amplified bass reproduction.
5) If the booster is used for the extension of the existing
car HiFi system, reduce the levels of the channels
which are too high to match the volumes of all chan-
nels 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.)
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