Blaupunkt MPA680 Install Manual page 7

I & C
NPUTS ONTROLS
The inputs and controls for this amplifier are explained in the summaries below and reference the numbered call-outs above.
1.) LOW-PASS CROSSOVER CONTROL (ch 3 & 4) - Once the "crossover
frequency setting" is set to "LOW-PASS", this control adjusts the frequency
for which all signals BELOW this setting are passed on to the speakers.
2.) HIGH LEVEL INPUTS (ch 3 & 4) - Should RCA cables not be available from the
radio you are able to tap onto the audio signal from the high level speaker
outputs of the radio. This is most commonly used when the amp is an add-
on device such as for a subwoofer system.
3.) CROSSOVER FREQUENCY SETTING (ch 3 & 4) - The internal crossover
frequency control setting of the amplifier can be switched to either the "flat"
frequency response position or in low-pass mode. On this amplifier, the
choice is for either 50-250 Hz in LOW-PASS mode or "flat" mode.
4.) INPUT GAIN CONTROL (ch 3 & 4) - This controls the gain setting on the input
of the amplifier. For high gain settings ( 0.3 volts), this says that it takes
ONLY 0.3 volts to drive the amp to full output. For low gain settings (near 4
volts), this says that it takes nearly 4 volts to drive the amp to full output. If
the amp is often going into distortion at only moderate volume settings on
the radio, rotate this control towards the 4 volts setting to reduce the
distortion.
5.) LOW LEVEL INPUTS - The more commonly used inputs, these are connected
to the standard RCA outputs available on nearly all aftermarket radios today.
These lines are dedicated to left and right outputs of the radio, be it for front
or rear speaker installations. The input gain settings of the amplifier (0.3 - 4
volts) are referenced to these inputs.
6.) INPUT GAIN CONTROL (ch 1 & 2) - This controls the gain setting on the input
of the amplifier. For high gain settings ( 0.3 volts), this says that it takes
ONLY 0.3 volts to drive the amp to full output.
7.) POWER "ON" LED - This light will turn on when the amplifier receives a +12
volt turn on signal from the radio in the vehicle. The input line to the "trigger"
connection must be properly connected to the radio's trigger line which is
often also the power antenna line. If the amp is properly wired, but the light
does not turn on, verify the trigger line is properly connected, is receiving +12
volts, and the speaker outputs are not shorted to themselves or ground in
any way.
8.) CROSSOVER FREQUENCY SETTING (ch 1 & 2) - The internal crossover
frequency control setting of the amplifier can be switched to either the "flat"
frequency response position or in high-pass mode, 50-500 Hz.
9.) HIGH LEVEL INPUTS (ch 1 & 2) - Should RCA cables not be available from the radio you are able to tap onto the audio signal from the high
level speaker outputs of the radio. This is most commonly used when the amp is an add-on device such as for a subwoofer system.
10.) HI-PASS CROSSOVER CONTROL (ch 1 & 2) - Once the "crossover frequency setting" is set to "HI-PASS", this control adjusts the
frequency for which all signals ABOVE this setting are passed on to the speakers.
1 2 3 4 5 6 7 8 9 10
"Floating Ground" Radio Outputs
RADIO CHASSIS GROUND -OR-
COMMON SPEAKER GROUND
High Level (Speaker Input) Wiring
– 7 –
P U T
V E L – IN
H IG H - L E
G A IN
R
+
-
-
+
L
M A X
M IN
GREEN
LEFT (+)
GREEN-BLACK
LEFT (–)
(NOT USED)
GREY-BLACK
RIGHT (–)
RIGHT (+)
GREY
P U T
V E L – IN
H IG H - L E
G A IN
R
- +
-
+
L
M A X
M IN
GREEN
LEFT (+)
GREEN-BLACK
(NOT USED)
GREY-BLACK
(NOT USED)
RIGHT (+)
GREY