Audio Systems/car audio


QUESTION: Hoping you can help. I want to install a second battery for my subs. Do I need to do the big 3 upgrade as well?

ANSWER: If the current needed to supply the subs when pumping out full bass then you should definitely be thinking of adding a battery.  Check out the specifications on your vehicle and see what the rating of the alternator is.  You will likely find it to be under powered which means you should also add a heavy duty, high output alternator.  Adding a big 1 or 2 farad capacitor will help smooth out the current draw and hold up the bass sounds a little as well.

So, if the subs are big pumpers and you want window shattering energy at 20Hz, you better do it all.  You can install the subs and experiment with bass output to be sure, but I am certain you will find it necessary to beef up the bass amplification system.

Let me know if you have more questions.  Best wishes.

---------- FOLLOW-UP ----------

QUESTION: Would it be necessary for 2 12 inch subs and 1200 watt amp? Or should I just get a capicter

A 1200W amp means that the audio system could draw in excess of 100 amps. Add to that other current requirements and the load on the electrical system may become as high as 120 amps during peak loads.  Check the rating of your alternator system. If it does not support at least 100 amps (many of American cars are rated only for 80 amps) then you should go for a high output alternator system.

Also, you must make sure the wiring that handles the high currents to the sub amp is big enough that loss of voltage is minimized.

Power caps can give some help, but once it has been determined that a higher output alternator will be required adding a big cap will not be a substitute solution.

Hope this gets you going the right direction.  

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Audio Design Engineer; systems, loudspeakers, cd/dvd players, etc. I am knowledgeable in all high end audio equipment and installations. MAKE SURE YOU GIVE A MAKE AND MODEL NUMBER AND CAR IF IT IS AN AUTO QUESTION. Note: I am getting some who ask good questions that take a lot of time to research but then the questioner fails to read the answer. Please don't ask questions unless you are seriously looking for an answer. If you find an answer to your question otherwise then let me know with your reply. Thank you.


Have been associated with audio design, standards, testing and component systems for over 40 years.

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