One of the questions most commonly asked of loudspeaker manufacturers concerns the matching of power amplifiers to loudspeakers.

Manufacturers will tell you that the majority of loudspeaker failures encountered by their service department are the result of improper power matching. It might seem logical to use a smaller amplifier as a safety measure; after all, it stands to reason that there won't be enough power to damage the loudspeaker.

Yet they see many more loudspeaker failures due to under powering than any other cause. When the amplifier exceeds its maximum voltage capability, it can "clip" the peaks off the electrical signal it is supplying.

Once the amplifier starts clipping, the average (or RMS) level rises, which can be extremely damaging to the loudspeaker. In layman's terms, for example, your 200-watt amplifier can approach delivery of 800 watts of power, but it will be volatile and heavily distorted, and thus potentially quite harmful to the loudspeaker.

However, using an amplifier that is much more powerful than the loudspeaker's rating can do just as much damage. Supplying the speaker with more power than it can handle will often result in thermal (heat) and/or mechanical damage.

Basically, any amplifier with a 20Hz - 20kHz power rating that matches other specifications of a given loudspeaker will safely drive that speaker at full output under most conditions. Therefore it's vital to understand the meaning and impact of the most important loudspeaker specifications as they relate to amplifiers.

First, there's power handling capacity, usually defined by terms such as "Continuous," "Program" and "Peak". Continuous is the level of long-term average power accepted by the loudspeaker; Program is based upon a test signal that simulates a "real-world" program signal; and Peak refers to the maximum amount of short-term power the loudspeaker will handle.

Based on these terms, then, what is the proper amplifier choice to capably and safely drive a loudspeaker rated at 100 watts continuous, 220 watts program, and 400 watts peak? The best choice would be an amplifier delivering about 200 (continuous) watts per channel. Plenty of power for normal full-range operation while also capable of meeting short-term peak demands without going into clip.