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Does Having A Subwoofer Drain Your Car Battery

Some people want to add enhancements to their music players so that they can have a different feel or experience to it. Car owners are not left out of this. The sound system of their vehicle might not be able to give them the sound they really want so they opt for enhancements like a subwoofer for more depth. Alas! This additional feature now makes you wonder if having a subwoofer drains your car battery. We will be answering some of those questions in a bit. Just stay tuned.

Does Having A Subwoofer Drain Your Car Battery

Without mincing words, yes! a subwoofer drains your car battery. This happens especially when you have your sound powered on, and the ignition of the car is powered off. This makes the woofer reliant on the charge of the battery. And because of the strength of the woofer and its amplifier, it could drain the battery quickly.

It could even get worse when the engine of the car is shut off and the subwoofer has to rely on the car battery for power. This would take a massive toll on the car battery and make it drain faster. A car battery gets charged by the alternator of the vehicle when the engine is running.

Apart from your car battery, a subwoofer can have adverse effects on other parts of your vehicle, especially if not managed properly. Listed below are some of the effects of having a subwoofer in your car.

Other Effects of a Subwoofer On a Car


The low frequencies of a subwoofer can cause a car to vibrate noticeably. This can occur when the resonance frequency of the vehicle is attained and exceeded. Resonance by the way, is the internal vibration frequency of a body.

Subwoofers are notorious for making cars vibrate unevenly. If the subwoofer works directly into the body of the vehicle, which is mostly made of iron frames, it ends up trapping sound and releasing it as echo.

The best way to notice this effect is when we feel a buzzing sound that’s in sync with the woofer’s sound. The windows and car frame also follow suit. This however, can be mitigated by having dampening materials to counter the effects of the uneven vibration.

Loosen car fasteners

Having a woofer in your car and playing it at very loud levels can make objects like bolts and nuts loose. This is possible by the vibrations made from the subwoofer. These bolts and nuts are used to hold the panels of the vehicle to its chassis and framework.

But excessive sound from the woofer can make the panel to vibrate excessively and hit against the chassis of the vehicle. If this continues to occur, over time, nuts, bolts and crews begin to loosen. The vehicle part most affected by this is the door panels. So if your woofer is large, it can pose a threat to your car.

Causes the trunk to sag

Subwoofers for vehicles come in different weight and sizes. These very between 8 to 12 inches. And normally, we feel that the bigger the woofer, the better sound it can produce. But the downside to this is that the bigger the subwoofer, the more weight it impacts on the trunk, because that’s the only place big enough to house it usually.

This extra weight will make the trunk of the car sag. When driving through uneven roads with hilly topography, the rear bumper of the vehicle might be grazing the road. This might in turn affect it and make it pull off. This happens mostly to smaller vehicles than bigger ones.

Effects on the alternator

An alternator is a device on the vehicle engine that converts mechanical energy to electrical energy which is used to power the electrical components of the vehicle and charge the car battery too. A woofer alone might not be able to damage the alternator of the vehicle, but when you add high power devices like an amplifier to it, because of the amount of energy required to power it, might cause the alternator to overheat, and might end up damaging it.

Therefore, the point we are trying to make here is that you should try and consider the power rating of your woofer and corresponding amplifier before installing it in your vehicle. So that it does not end up being a burden on your alternator.

Shatter car windows

Yes! This is possible though it is less likely to happen. The car window is a highly tempered glass, but if there is a crack on it already, the loud volume of the woofer and its strong vibrations can shatter it. Remember what we said about resonance.

The car window has this also, and once this vibration level is exceeded, it isn’t good for the window. However, though this is possible, it is less likely to happen because the power rating required to shatter tempered glass is very high and hard to come by.

Types of Car Subwoofers

There are lots of woofers for cars these days, but the idea here is to get one that won’t pose a threat to the electrical system of your vehicle, especially the battery. Some of these subwoofers are as follows:

Kicker 44DCWC122 12″ 1200W Car Audio Subwoofer

Kicker has been in existence since 1973, in Oklahoma, USA. So you can be rest assured that they have had years of solid experience producing quality subwoofers. This unit houses two cabinets with anti-vibration and reinforced bracings. Its body frame it quite large, measuring about 36x24x18 inches in dimensions. It weighs about 60 pounds. At peak load, these woofers have power of 1200 watts. The woofer cones are made of polyurethane which is necessary to reduce distortion.

Kicker 44DCWC122 12″ 1200W Car Audio Subwoofer

Rockville RWS12CA

This is a very portable woofer that does not take up much space in the trunk of your car. It has a sealed, slim unit, protected by aviation graded carpet. It weighs just about 30 pounds and measures 25x15x4 inches. The Rockville RWS12CA is equipped with Kevlar reinforcements to dampen excessive vibrations from its 1200-watt power drawl. The size of this woofer makes it mobile and easy to carry around. It won’t bear much weight at the trunk of your car.

Rockville RWS12CA

Alpine Type R 12

This woofer is the high-powered type we talked about earlier. At peak load, it has a wattage of about 2250. It has a 12-inch subwoofer cone that announces itself with every sound. However, with all of these, the Kevlar insulation makes it difficult to transfer large vibrations to the panel and framework of the vehicle.

Alpine Type R 12

This subwoofer weighs about 26 pounds with 14.5×14.5×9 inches in length, breadth and depth. The Alpine Type R 12 has very deep aggressive bass sound, but worry not. It has enough insulation to dampen its high frequencies.

Kenwood KSC-SW11 150W

For people who don’t want anything extraordinary but just a decent upgrade to their already existing sound system, then this subwoofer is definitely for you. In the game of sound gears and equipment, Kenwood is a household name. In fact, in 2008, they partnered with another power house called JVC.

We are going through all these to make you know that because this woofer might not be as noticeable as the others mentioned above, you are still getting good value for your money. It weighs about 10 pounds with 16.2×9.8×4.2 inches. It is easy to carry about and fits in just nicely in the trunk of your car.

JBL BassPro Micro Dockable Powered Subwoofer System

For people who have little space in the trunk of their car and don’t want anything making it look saggy, this 18 pounds 7x16x10 inch subwoofer is just enough to go by. It is very beautiful to behold with a chrome rim and a matte black finishing. It also has a peak load of 140 watts.


Surround sound is nice and enjoyable, but we must make sure that it does not pose any threat to the car, its electrical system and ultimately the car battery.