A passive speaker is one that is not powered. It is powered by a cable from a separate amp. This is how it usually goes. :
Sound source –> Pre-Amplifier (abbreviated to ‘preamp’) –> Power Amplifier (abbreviated to ‘amplifier’ or simply ‘amp’) –> Crossover –> Speaker
Sound Source: This can be many things including a :
- music streamer
- CD player
- Blu-Ray player
Preamp: This allows you to pick the source and volume you want the sound to originate from.
Amplifier: This amplifies the signal from the preamp so that it can drive the speaker.
Crossover: The signal from the amplifier is separated and sent to the several 'drivers' of the speaker. One loudspeaker can have many drivers. In reality, each driver is a separate speaker. A woofer, midrange, and tweeter are frequently found in the same loudspeaker, which means the crossover will split your signal three ways. It would divide in two if you just have a midrange and tweeter.
Speaker: The speaker might be a single driver or, as mentioned above, many drivers in one unit.
An active speaker, unlike a passive speaker, has an internal crossover and is driven by an internal amplifier, thus it does not require an external power source. As a result, the typical progression is :
Power Source –> Preamp –> Crossover –> Amplifier –> Speaker
In fact, in a powered speaker, each driver normally has its own amplifier.
Are powered speakers and active speakers the same thing? The simple answer is no. The long answer is that both active and powered speakers are powered. However, not all powered speakers are active, and not all active speakers are powered. Some powered speakers use the same signal path as passive speakers, but the preamp and power amplifier are both disguised within the device, providing the impression of an active speaker.