A passive amplifier, also called a passive speaker, is a device that amplifies an audio signal without needing an external power source. It achieves this by utilizing the energy of the audio signal itself to increase its amplitude.
The key component of a passive amplifier is the driver or loudspeaker, which converts the electrical signal into sound waves. The driver is usually mounted inside a box or enclosure that resonates with the sound waves produced by the driver, amplifying the sound output.
Passive amplifiers are designed to produce the best possible sound quality, and their enclosures are optimized to match the frequency response of the driver. This involves using materials with specific acoustic properties and designing the box's size and shape to enhance the sound quality.
Passive amplifiers are commonly used in home stereo systems, musical instrument amplifiers, and public address systems. They are often less expensive and lighter than active amplifiers, which require an external power source. However, they may not be as powerful as active amplifiers and may not deliver the same level of sound quality.