Anonymous asked in Cars & TransportationCar Audio · 1 decade ago

Another question about my speaker & amplifier setup?

Having a 800 watt Rockford Fosgate 2 Channel Amp, hooked up to one 12 inch Kicker L7 Solobaric in bridged mode, I decided to purchase one of those capacitors to help ease the strain on the battery. I purchased a Legacy 2.4 Farad Cap but it dosen't seem to have an affect as my lights still dim when I crank up the volume. I assume that I didn't get the right cap because not too long ago my battery still went dead(the battery is not old , I just got it about 5 months ago). I've seen a couple of people in photos install a extra battery in their vehicles, with the amps hooked up to them. I would like to know if I'd be better off investing in another battery and hooking it up, or just getting a stronger cap? Which farad should I get for the setup I have right now?

I appreciate the help!

4 Answers

  • 1 decade ago
    Favorite Answer

    Lightning caps are generally considered in the sound world as a band-aid when you really need stitches. The amp already has capacitors in it.

    Second point: a 2.4 farad cap should technically power over 2000 watts. In your case a 1 farad cap should've been more than plenty.

    Probably the best thing you could do for your sound setup is get a heavy duty alternator. At 800 watts, it's not that much, so if it's dimming your lights, the alternator isn't strong enough.

    The second best thing is as you mentioned is to install a second battery. You'll need very heavy (0 guage) wiring to do this, and the time spent mounting it and running wires is probably equal to an alternator, while being less safe.

    This goes without saying but I'll say it anyway - running 800 watts with the car off is a great way to kill your battery very quickly regardless of what setup you have.

    • Commenter avatarLogin to reply the answers
  • Anonymous
    1 decade ago

    Depending on the amperes of your alternator, you might need to upgrade. A second battery is never the answer and is only a band-aid to a problem that will come back.

    If your alternator is 35 amps (compact cars), then you will need to upgrade. Most standard sized cars are 65-75 amps and SUV's are around 145 amperes. Allow 40% of the amperage of the alternator to power the vehicle.

    To calculate the approximate average power consumption, multiply the total watts RMS of the amplifier(s) by two and divide by the voltage of the car when running (13.8 volts). Divide this number by three for inefficiency.

    Assuming it's 800 watts RMS...

    800 * 2

    1600 / 13.8 = 115.94

    115.94 / 3 = 38.64 ampres

    This is an average approximation and can go higher. So I would gather between 39 and 58 amperes for this system.

    Source(s): 25 year electronics technciain, audio guru
    • Commenter avatarLogin to reply the answers
  • 4 years ago

    basically to enable u understand your 12L7 is 1500watts cuz that's twin voice coals that's 750 a voice coil i had 2 12L7 u can run it off the punch 800 bridge basically makes confident the sub is broke in extremely good beforehand u crank it up or you'll blow your sub. solobarics are sum of the superb subs available i had 2 L7 12's operating off a 300watt amp and that i damn close to blow my decrease back window out. have relaxing i'm upgrading to the solo X!!!!!!!

    • Commenter avatarLogin to reply the answers
  • 1 decade ago

    the wire that feeds your amp power is probably to small,check this out..speaker wire size also??

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.