New Car and Power Question

Discussion in 'Automotive Electrical' started by 09GalantDriver, Jan 22, 2012.

  1. 09GalantDriver

    09GalantDriver New Member

    Im looking at picking up a new vehicle here in the next few months. I dont feel like paying the rediculous price tag for the upgraded sound system only to get moderate performance. With that being said and the fact that the car will be brand new, I want to do as little to void any warranties as possible. So if I can avoid it I dont want to do the big 3, or install a 2nd battery, or upgrade to a HO alternator.

    However, Im looking to probably replace the headunit, doors w/ some descent components, add some woofers.

    Im a 1/2 descent installer but am not perticularly well versed in the eletrical so im looking for some advice here.

    Im looking to install a alpine mrp-500 (500watt) w/ 2x 12'' alpine type e's


    a alpine mrx-m100 (1000watt) w/ 2x 12'' alpine type r's

    So if I follow the logic here the car has a 140 amp alternator. Assuming the car will take a normal 20% amp draw that leaves: 12v X 112 amp = 1344 watts.

    Id obviously want to go with the type r's if its possible.
    So, theoretically that leaves the alt with 344 watts if I go with the 1k watt amp and the type r's.

    Is this enough to regularly charge the battery? Should I be concerned? Will I be able to run the stereo for long with the car off? Opinions on Caps? (1/2 the reviews I read say their useless 1/2 say there important) Or should I just go for the type e's with less draw and call it a day?
  2. steve

    steve Full Member

    forget the caps, get a deep-cycle battery and you should be fine.. by the way ......Here is a simple way to determine average current draw on the electrical system
    (total rms continous watts * .50 / amplifier effeciency / cars voltage = average current
    draw on cars electrical system).this is intended for musical signals not tone generators.
    the reason for multipling by .50 is that .50 represents a musical signal driven to the
    point of distortion.for bass reproduction you may use (.60).if there is more than one
    amplifier used,simply combine the results of all amplifiers.