Differences Between Passive, Powered and Active Speakers
The terms "powered" and "active" have been used interchangeably in regard to loudspeaker designs, however, a differentiation may be made between the terms:
- In a passive loudspeaker system the low-level audio signal is first amplified by an external power amplifier before being sent to the loudspeaker where the signal is split by a passive crossover into the appropriate frequency ranges before being sent to the individual drivers. This design is common in home audio as well as professional concert audio.
- A powered loudspeaker works the same way as a passive speaker but the power amplifier is built into the loudspeaker enclosure. This design is common in compact personal speakers such as those used to amplify portable digital music devices.
- In a fully active loudspeaker system each driver has its own dedicated power amplifier. The low-level audio signal is first sent through an active crossover to split the audio signal into the appropriate frequency ranges before being sent to the power amplifiers and then on to the drivers. This design is commonly seen in studio monitors and professional concert audio.
Hybrid active designs exist such as having three drivers powered by two internal amplifiers. In this case, an active 2-way crossover splits the audio signal, usually into low frequencies and mid-high frequencies. The low-frequency driver is driven by its own amplifier channel while the mid- and high-frequency drivers share an amplifier channel the output of which is split by a passive 2-way crossover.
Read more about this topic: Powered Speakers
Famous quotes containing the words differences, active and/or speakers:
“Quintilian [educational writer in Rome about A.D. 100] hoped that teachers would be sensitive to individual differences of temperament and ability. . . . Beating, he thought, was usually unnecessary. A teacher who had made the effort to understand his pupil’s individual needs and character could probably dispense with it: “I will content myself with saying that children are helpless and easily victimized, and that therefore no one should be given unlimited power over them.””
—C. John Sommerville (20th century)
“How often must I repeat, that I know or am conscious of my own being; and that I myself am not my ideas, but somewhat else, a thinking, active principle that perceives, knows, wills, and operates about ideas?”
—George Berkeley (1685–1753)
“What’s this, Aurora Leigh,
You write so of the poets and not laugh?
Those virtuous liars, dreamers after dark,
Exaggerators of the sun and moon,
And soothsayers in a tea-cup? I write so
Of the only truth-tellers, now left to God,—
The only speakers of essential truth,
Opposed to relative, comparative,
And temporal truths;...
The only teachers who instruct mankind,
From just a shadow on a charnel-wall.”
—Elizabeth Barrett Browning (1806–1861)