Question about Alpine MRP-M650 Car Audio Amplifier

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Ok i got an amp installed and would most of the time not have any sound. power is on(has the light). wat am i doing wrong?? also, when it does work my amp shuts off. and when i turn power on, light comes on and fades away immediately. are all these problems related?? pretty sure all cables are connected

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  • mista808 Jan 12, 2008

    amp is brand spankin new and i understand the remote wire prob but please explain the voltages to/at amp more. THX A LOT FOR REPLYING!:)

  • mista808 Jan 12, 2008

    wat if it does turn on but no sound? wat does dat meen?

  • mista808 Jan 13, 2008

    i changed the battery fuse. ok now!!! one last thing, if the rms power on my amp is 40watts rms x 4, wat setting will i hav the gain on?? i.e. full gain means the full 40?? or half the gain is the ful 40??



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Check voltages at the main power lead to/at the amp and also
at the sense wire which switches it on when the radio is on.
Might be the wiring is too thin and is switches off when current is drawn bigger than that needed to light up the light?
That or the switching power supply inside the amp is unstable/dead.

Posted on Jan 12, 2008

  • Anonymous Jan 12, 2008

    Voltages should be about the same as measured on the car battery and
    could drop a bit when the amp switches on. They will have to be around
    12 volts for the power supply in the amp to switch on and when <10v
    there is a wiring problem. If this is the case you should run thicker
    wiring from battery to amp and *do* run both + and - wiring. Never use
    only the red + and wire the black - to the car's chassis. As a test you
    could try connecting the amp close to the battery with short cables and
    see if it will turn on.

  • Anonymous Jan 13, 2008

    In theory you should be getting the full power when the volume control is turned all the way up. In practice the output voltage of your radio is more then needed to drive the amp to it's max so somewhere near the end you will already be getting full power.

    Volume controls work logarithmic to compensate for the sensitivity curve of our ears and most of the time you will only use a few watts of power for a decent listening experience. Only the peaks in the music will drive the amp to it's max as 4x40 real watt's is enough to deafen you when driven into good speakers :)



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