If the total loudspeaker impedance is too high, the power delivered to the loudspeakers will be reduced. Audio amplifiers are commonly designed to work with 4, 8 or 16 ohms of resistance, and optimum system performance can be obtained if the total ohm load of the loudspeakers is exactly correct for the amplifier.

It may surprise you to learn that low power can result in damage to your speaker or system.

If budget restraints or legacy equipment force you to use an amplifier with less power, extreme care should be taken to see that the amplifier is not driven into clipping. For these applications, use an amplifier that can deliver two- to four-times more power than the speaker’s program power rating. In some applications, such as critical listening in a studio environment, it is important to maintain peak transient capability. Consult the amplifier manufacturer or owner’s manual to learn more. In this case select a model with an output power rating equal to the program power rating of the speaker. These amps can cleanly reproduce transient peaks that exceed their rated power. Music has wide variations in dynamic range without enough headroom, you’ll find your gear clipping (distorting) far too frequently! Some professional amplifiers are designed so they have additional headroom. Headroom is the difference between the normal operating level of an amplifier, and the maximum level that the amp can pass without distorting. Using an amp with some extra “headroom” will help assure that only clean, undistorted power gets to your speakers. A quality professional loudspeaker can handle transient peaks above its power rating if they occur. For a stereo pair of speakers, the amplifier should be rated at 700 watts per channel into 8 ohms. This means a speaker with a “nominal impedance” of 8 ohms and a program power rating of 350 watts will require an amplifier that can produce 700 watts into an 8-ohm load. When you’re matching a power amp to a PA speaker setup, a good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker’s program rating.

Power amplifier pa