Speaker Power Handling Specs

Speaker power handling specifications are usually meaningless. Typically, you just see a “maximum power” rating with no explanation as to how the spec was derived. Is it the maximum continuous level? Average level? Peak level? And for how long does it sustain, and with what type of material? These are also important questions. Different authorities released several, conflicting standards for measuring speaker power handling, published by the Audio Engineering Society, the Electronics Industries Association, and the International Electrotechnical Commission. It’s no wonder that the average person often ends up confused! On top of that, most of the manufacturers don’t actually follow these standards; they simply make an educated guess. Often, this decision is based on the power handling of the subwoofer. (Power handling specifications on raw speaker drivers, such as woofers and tweeters, are more standardized and meaningful than specs for complete speakers.) Sometimes a speaker power handling spec is based on marketing. You may even see a manufacturer give a more expensive speaker a higher power handling rating versus a lower-priced speaker, even though they both use the same woofer.

Volume Settings vs. Amplifier Power

In most situations, a 200-watt amp puts out exactly the same power as a 10-watt amp, because most listening occurs at average levels, where less than 1 watt is enough power for speakers. Into a given speaker load at a given volume setting, all amplifiers deliver exactly the same amount of power—as long as they’re capable of delivering that much power. So it’s really the volume setting that matters, not the amplifier power. If you never crank up your system to the level where the volume is uncomfortable, your amp may never actually put out more than 10 or 20 watts. Thus, you can safely connect a 1,000-watt amplifier into a little 2-inch speaker. Just don’t turn the volume up beyond what the speaker can handle. What you shouldn’t do is plug a low-powered amp—say, a 10- or 20-watt model—into a typical speaker and turn the volume very loud. The low-powered amp may clip (distort), and amplifier clipping is the most common cause of speaker failure. When your amplifier is clipping, it’s really outputting a high-level DC voltage straight into the speaker, which can burn out the speaker drivers’ voice coils almost instantly.

How to Calculate What Size Amp You Need

Confusing as all this may seem, it’s easy to calculate what size amp you need. And the best part is that you can do this in your head. It won’t be perfect, because you’ll be relying on the specifications from the speaker and amplifiers, which are often vague and sometimes exaggerated. But it’ll get you close enough. Here’s how to do it: So what you’ll need is an amplifier capable of delivering 32 watts. Of course, no one makes a 32-watt amp, but a 40- or 50-watt receiver or amplifier should do fine. If the amp or receiver you want puts out, say, 100 watts, don’t worry about it. Remember, at average listening levels with typical speakers, any amp is putting out only about 1 watt, anyway.