Audiophiles understand the importance of speakers in a home entertainment set-up. This is arguably the most important decision made when purchasing and assembling the audio components for the system. It is certainly one of the first features shown off when fellow audiophiles drop in for some aural sampling. When selecting speakers, consumers may find themselves confronted with the option of active speakers, passive speakers, powered speakers, or some combination. To make life more difficult, not all vendors and experts agree on the usage of those terms. We’ve attempted to clear up the confusion and spell out some of the strengths and weaknesses.
Defining Active, Passive, and Powered
The terms passive, active, powered, and unpowered are often confused and used incorrectly, or at least interchangeably. The confusion lies in what, specifically, is being addressed with regards to the speaker. When used, these terms are either in reference to speaker amplification or speaker crossover. Hence, active is sometimes used interchangeably with powered, and passive with unpowered. Here’s a quick breakdown:
In an active speaker, the word active commonly refers to the crossover components/system. The crossover components in an active speaker split the frequency band of the audio signal into smaller parts (low, high, and sometimes mid-range), which are then sent to individual speaker drivers designed to handle those frequencies.
Where an active speaker has electrical crossover components and powered amplifiers for each driver, these speakers are, themselves, “powered.” This is why active and powered are often used synonymously. So, when a speaker is referred to as active, it is nearly always referring to the crossover components, which by definition require amplifiers for each band, and separate power.
Incidentally, active speakers suitable for home entertainment and home theater solutions most commonly house the active crossover components and amplifiers within the speaker enclosure, but this is not always necessarily the case. In larger home theater settings, the crossover components and amps can be outside of the speaker. With an active speaker system, one will often see “active speaker” with “bi-amp” or “tri-amp” scenario, referring to active crossover and two or three separate amplifiers for the separate drivers.
Bart LoPiccolo, National Sales Manager for Genelec, Inc., takes the definition of active a few steps further, explaining that Genelec’s speakers are active because, “they have active electronic crossovers before the amps, they have dedicated amps for each driver, each channel has protection, and there are room response controls per driver.” Active speaker proponents like LoPiccolo believe that an active speaker system has certain advantages over a passive system due to the fact that the crossover components, amps, drivers, and speaker enclosures are all manufactured with one another in mind.
In contrast to the active speaker, passive speakers feature:
- passive crossover components, which split the audio signal and send each band directly to the loudspeaker drivers
- audio signals that are driven by a separate, individual amp
- components that are typically an arrangement of resistors, capacitors, and inductors, which split the signal and send each frequency part to the drivers
- a separate power amplifier that sends the full audio signal to the speaker(s)
Although high-end passive speakers can contain high-end crossover components, LoPiccolo says that, by nature, passive crossover components and passive speakers have some intrinsic drawbacks. “Passive crossover systems dissipate heat, and can lose as much as 30-percent of the amplifier’s power,” LoPiccolo states. “And as the crossover components heat up, the performance of the speaker changes. So a movie may sound differently toward the end than it did in the beginning,” he continues.
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