Amplifiers
Amplifiers are usually placed away from head unit of the audio system in a car so that it can dissipate the maximum amount of heat produced.
Purpose of use
Amplification is the final step in the audio playback chain and its purpose is to amplify the electrical audio signals from its earlier stage to a level that can drive the loudspeakers. Signal amplification is generally a two-step process, which is executed by two separate components, namely, pre-amplifier and power amplifier. Pre-amplifiers, also known as low power audio amplifiers and are responsible for amplifying tiny signals, equalisation, tone control, mixing effects, etc or audio sources like record players, CD players, cassette players, etc. Pre-amplifier puts out a signal inaudible to the human ear. The power amplifier takes over at this stage.
Power amplifier is responsible for taking the signal from preamplifier and boost it into the human audible range.
Design of Amplifier
The basic design parameter of audio amplifiers includes the following:
- Frequency response is used to measure any audio system's response at the output to a signal of varying frequency at its input. The term is usually referred to in reference with loudspeakers and similar systems.
- Gain is a term that has wide application in amplifiers. It is usually considered as the mean ratio of the signal output of a system to the signal input of the system.
- Noise can be referred to as a disturbance that affects a signal and may therefore alter the information carried by the signal.
- Distortion is defined as the alteration of the original characteristics of sound. Effects of distortion are sometimes considered as noise.
There are several important application of amplifiers. Some of the common application of amplifiers in audio systems are:
- Home and car sound systems
- Public address systems
- Stereo or home-theatre system
