Looking to get seat-shaking rumble and thumping low bass from your car stereo? Not only will you need great speakers with lots of volume and a car receiver, but you will also need the one device that will give you that rumble: a subwoofer.
* Separate dedicated amps are required in order to power the subwoofers.
* Choosing between a powered or unpowered amp? Opt for a powered one which has fewer wires, more bass control, and more power left over for the other speakers.
* For simple installation, get an enclosed subwoofer system. That means you don't have to search for car subwoofer enclosures, which are sold separately from most subwoofers, and mess with installing them at all. Unless of course if you like that sort of thing, then go for it. While you are at it, you should build your own enclosures.
* If you want really clear sound then you might need a crossover. They filter out high-frequency noise, aka, shrills, thrills, and otherwise non-rumbling sound. Low-pass filters for your sub will do the trick if they are not already built into your amp. The only case for really having to buy one is if you have a multi-amp system.
* Keep in mind:
** Where you are going to place the subwoofer.
** The size of your vehicle.
** How much bass you want.
* Usually cars don't need more than two small subwoofers.
** For a small vehicle you could get enough power from just a 10" subwoofer and an amplifier.
** For larger vehicles, try either two 10" subs or one 12"-14" plus an amp.
* Always check the wattage, ie RMS, on your stereo or receiver. If your stereo doesn't have the power, then don't expect that your sub will get enough power to perform to its fullest. Most of the time you will need to purchase a separate amplifier.