How to Power a Car Amp in Your Home

You could one day find it necessary or convenient to use a car audio amplifier to power your home speakers. Removing an amplifier from a car or purchasing an aftermarket car audio amplifier from an automotive custom audio shop is a starting place. It's not necessary for the amplifier to ever be or have been installed in a car. High-power car audio amplifiers can have operating specifications that rival even the most costly "designer" audio amplifiers. Providing proper DC electrical current (amperes) to a car audio amplifier in a home is necessary to ensure its peak performance.

Things You'll Need

• Car audio amplifier
• AC 110 volt to 12 volt DC regulated or switching power supply with binding posts (output meters optional)
• 10-gauge electrical wire (custom cut or in a retail cable kit)

Instructions

1. Decide on the total output wattage you want for your amplifier. This number is the amount of electrical power that the amplifier can produce at any speaker or combination of speakers.

2. Check the watts rating on particular or specific brand names of amplifiers. You can do this by reading information on the packaging of the amplifier or by reading the specifications information on websites. Often the name of the amplifier will provide the wattage. (A fictional example of a 1,000-watt amplifier could be Car Tech Extreme Car Amplifier P-1000.)

3. Acquire an AC-to-DC regulated or switching power supply with sufficient output amperes to power the amplifier to its stated output (1,000 watts). Alternatively, if there is a power supply already available, determine if it can power the amplifier to its rated output. (See the "Tips" section for help on how to calculate this requirement.)

4. Connect the power supply to the car amplifier using the 10-gauge wiring kit. Make certain the black wire is connected to the black or (-) binding post and the red wire is connected to the red or (+) binding post on both the power supply and the amplifier. Crossing these connections creates a risk of explosion or fire from the power supply and amplifier.

5. Connect the speakers to the amplifier before turning on either the power supply or the amplifier. Forgetting this step risks overloading the amplifier and causing it to burn out before ever getting to hear how it sounds in the home.

Tips & Warnings

• Although this article suggests an amplifier output power of 1,000 watts, any wattage can be used. However, the power supply must be able to provide "regulated" output power/amperes/voltage. Verify this specification by carefully reading the package, the specifications sheet or the specifications tab on a website. The ability of the power supply to provide the needed amperes to power the amplifier to its stated watt output is determined by Ohm's Law. First, divide the maximum wattage desired (that's the amplifier's rating) by the resistance of the speakers (usually 4, 8, 12 or 16 ohms). Next, use a calculator to determine the square root of the quotient. Don't let the electronic terms cause confusion; use watts, ohms and amperes to ensure the right numbers are in the right places. For example, 1,000 watts (amplifier) divided by 4 ohms (speaker resistance) equals 250. The square root of 250 is 15.811388, which is the value of amperes needed to drive your 1,000-watt amplifier. Power supplies are available that can be set to a value this precise, but they might carry attendant higher price tags. You can purchase a well-made, dependable regulated power supply capable of producing 15 amperes for between $100 and $150. This is sufficient to effectively power a 1,000-watt amplifier.

• AC and DC amperes at these levels can be lethal. Make certain when connecting the power leads to the amplifier that the power supply is unplugged from the AC wall socket. Incorrect connection of the leads at the power supply or amplifier can destroy the power supply and amplifier. An explosion or fire can be caused due to incorrect connections. Double check all connections before turning on the power supply. A measurement of loudness at the speakers known as "sound pressure" can cause hearing loss if it is too high for too long a period of time.