Total system power is a term often used in audio electronics to rate the power of an audio system. Total system power refers to the total power consumption of the unit, rather than the power handling of the speakers or the power output of the amplifier. This can be viewed as a somewhat deceptive marketing ploy, as the total power consumption of the unit will of course be greater than any of its other power ratings, except for, perhaps, the peak power of the amplifier, which is essentially an exaggerated value anyway. Shelf stereos and surround sound receivers are often rated using total system power.
One way to use total system power to get a more accurate estimate of power is to consider the amplifier class which would give an educated guess of the power output by considering the efficiency of the class. For example, class AB amplifiers are around 25 or 50% efficiency while Class D amps are much higher; around 80% or more efficiency. A very exceptional efficiency for a specific Class D amp, the ROHM BD5421efs, operates at 90% efficiency.
In some cases, an audio device may be measured by the total system power of all its loudspeakers by adding all their peak power ratings. Many home theater in a box systems are rated this way. Often low-end home theater systems' power ratings are taken at a high level of harmonic distortion as well; as high as 10%, which would be painfully noticeable.
Famous quotes containing the words total, system and/or power:
“Of lower states, of acts of routine and sense, we can tell somewhat; but the masterpieces of God, the total growths and universal movements of the soul, he hideth; they are incalculable. I can know that truth is divine and helpful; but how it shall help me I can have no guess, for so to be is the sole inlet of so to know.”
—Ralph Waldo Emerson (1803–1882)
“A person, seasoned with a just sense of the imperfections of natural reason, will fly to revealed truth with the greatest avidity: while the haughty Dogmatist, persuaded that he can erect a compleat system of Theology by the mere help of philosophy, disdains any further aid, and rejects this adventitious instructor.”
—David Hume (1711–1776)
“We have heard all of our lives how, after the Civil War was over, the South went back to straighten itself out and make a living again. It was for many years a voiceless part of the government. The balance of power moved away from it—to the north and the east. The problems of the north and the east became the big problem of the country and nobody paid much attention to the economic unbalance the South had left as its only choice.”
—Lyndon Baines Johnson (1908–1973)