You've got a subwoofer, or you're thinking about getting one. Great idea. Whether your goal is to build a system with head-turning, ground-pounding bass, or to improve the sound of a low-powered factory system, a sub can do wonders.

Providing your sub with the right amount of power is key to getting it to perform properly. Let's take a look at what to consider when selecting an amp.

What's up with watts?
Even if you're a novice to car sound, you've probably heard people talk about watts. Watts are simply a way to measure power. In the same way that a car with more horsepower can accelerate more quickly and go faster, subwoofers and amps with higher watt ratings can offer you better sound quality and louder performance. If you're looking for real depth and clarity at any volume, look for high power.

Here's an important, often misunderstood point to remember. When we talk about power in amplifiers, we're referring to the power output of the amp. When we talk about subwoofers, we're discussing power handling — how much power can be sent to them.

This amp proudly displays "500 watts" on the front, but it's RMS power rating is actually only 350 watts.

RMS power vs. peak power
Don't be confused by "peak power" and "RMS power" ratings. Simply put, RMS wattage ratings are a measure of continuous power — while different manufacturers will use somewhat different methods to come up with these figures, it's usually a more "real-life" rating of your equipment's capabilities. Peak power, on the other hand, doesn't try to reflect realistic operation. It's simply a measure of how much power can be generated or handled for very short bursts.

Many manufacturers emphasize peak power ratings by stamping these ratings on their subwoofers and amplifiers. As we noted before, peak power ratings are not realistic measures of the true power capabilities of the equipment. By comparing the RMS power rating of the sub and the RMS power rating of the amp, you'll have the tools you need to pick the right equipment.