There are literally thousands of different types of audio amplifiers on the market. It is not surprising that given the flood of different models it is quite difficult sometimes especially for novice to navigate the maze of different types of products. In the next few sections I will try to outline some of the basic types of audio amplifiers. I will also highlight which type of amplifiers a suitable for which purpose.
Before purchasing an audio amplifier, it is important to figure out what exactly you are trying to accomplish. Different models of audio amplifiers are usually optimized for different purposes. For example, car amplifiers optimized to operate from a limited voltage supply. A car battery, for example, offers 12 volts of power. This voltage is fairly low. Without stepping up the voltage, audio amplifiers would be unable to drive his speaker to a high volume. In addition, the car battery does not supply is stable voltage. The voltage is subject to fluctuations and also will decrease as the battery is being discharged.
So if you installing an amplifier inside your car, you will need to pick an amplifier that provides an internal step up converter. This step up converter is designed to converts the battery voltage of typically 12 V to a higher voltage which is used to drive the internal power amplifier stage. Depending on your speaker impedance, the amplifier requires a significantly higher voltage in order to work. Also, car amplifiers are designed to be mountable to a car. Obviously, when in motion, the amplifier has to be fixed properly as not to become detached. So the enclosure needs to be fairly rugged.
Another important application of audio amplifiers are home theater speakers. These speakers are usually set up in groups. Normally, you would need a separate amplifier for each speaker. Of course, if you’re working with wireless speakers then you wouldn’t need an amplifier because speakers would have the amplifier already built in. Most home theater receivers include amplifiers to drive the speakers. You can see by looking at the back of the receiver how many speaker outputs are available.
For listening to music, a stereo amplifier would do the job. You just need to channels, one for the left speaker and one for the right speaker. Stereo amplifiers usually offer higher fidelity than home theater amplifiers. Also, there wattage is typically higher. That is because the only have to incorporate two channels versus six to eight channels.
When choosing a suitable amplifier, make sure the amplifier is designed specifically for your application. In addition, look at the specifications to find out whether the amplifier offers enough wattage for your speakers. Also, make sure that the speakers that you are planning to use with the amplifier are ported. Some amplifiers are unable to drive speakers if the impedance is lower than the minimum rated impedance.