Passive speakers, also known as unpowered speakers, do not have their own integral signal amplifier. Speakers with a built-in amplifier are called powered speakers. Some powered speakers may also be active speakers, but this is not always the case. Passive speakers also have passive, or unpowered, electronics systems for splitting the incoming audio signal into frequency bands for the individual drivers in speakers that have more than one.
Most standard speakers are passive and require only a connection to a stereo receiver or amplifier. Passive speakers only have connections for an amplified audio signal, which is usually a wire with two independent strands, although the speaker may not have its own wires but simply connectors for attaching such wires. An amplified audio signal is an audio signal that has been strengthened by a separate component before being sent to the speaker. The most common such components are receivers and amplifiers. A receiver is an amplifier that also has standard radio signal receivers, although many amplifiers and receivers have other features, like the ability to switch between input sources.
Many consumers prefer passive speakers for a number of reasons. They are lighter than similar powered speakers, sometimes considerably so, and usually smaller as well. A separate amplifier means that the speaker itself is simpler and more affordable. This type of system arrangement also means that speaker or amplifier components may be changed separately, as desired or needed. Powered speakers do not allow for this kind of flexibility in system upgrade and design. Since wiring requires only audio signal wires, setting up and connecting a system with passive speakers is generally less complicated.
Some audio enthusiasts prefer powered speakers, however, and feel that the drawbacks of passive speakers make them an inferior choice. The best choice is really a matter of preference, as either type of system can be configured for excellent performance. The main drawback of passive speakers is that they lose signal strength as the distance between the speaker and the amplifier increases, and the degree of loss can be potentially significant. Passive speakers must also be matched with amplifiers that have the proper specifications for best performance, while powered speakers are built with appropriate amplification components included.