Looking at recent audio amplifier products, one cannot help but be overwhelmed by the number of technologies and models. I will clarify some fundamental amplifier vocabulary and help you pick the right type regardless of what your specific use may be.

Audio amplifiers are indispensable because your audio source such as your DVD or Blu-Ray player does not provide a signal powerful sufficient to drive your speakers. The amplifier will be the bridging element to your loudspeakers. It will convert the weak source signal to a signal powerful sufficient to drive your speakers.

Some audio sources such as surround-sound receivers already come with a built-in audio amplifier. Utilizing a separate amplifier, however, offers some advantages. One benefit is possessing more flexibility and being able to pick an amplifier that is best suited to drive a particular speaker. There are some mini amplifier models available. These types are small sufficient to conceal almost everywhere.

Many people will look at amplifier wattage first when picking an amplifier. Output wattage is the level of power the amplifier is capable to deliver to the speakers. Driving low-sensitivity speakers (sensitivity is shown in dB/W) calls for fairly high wattage. Moreover, driving outdoor speakers or speakers in a large room will require higher amplifier power. However, be cautious not to overdrive your speakers. This can damage your speakers beyond repair.

Yet, amplifier wattage is not everything. Good sound quality is perhaps more important than raw power. A 20 to 50 Watt amp ought to be sufficient for most real-world applications.

There are two conventions for specifying amplifier wattage. The first one specifies how much power the amplifier is able to deliver continuously. That figure is often called rms or continuous power. The second number is referred to as peak or maximum power and tells how much the amp can deliver for small bursts. Typically you should pick an amplifier based on rms power. However, make certain that the amplifier has adequate headroom or peak power to avoid clipping of music signals.

There are other parameters that are more important than wattage when selecting an amplifier. One significant parameter is referred to as total harmonic distortion or THD in short. No amplifier is ideal. There will be some amount of signal distortion which is created by the amplifier. The amount of distortion is expressed in percent or dB. The level of distortion varies between amplifier types. A smaller distortion means higher audio quality. The amount of distortion will be less than 0.05% for a high-quality amplifier. Consumer type amplifiers have higher distortion figures. Typical figures are up to 10% depending on the output power.

Another figure related to audio quality is known as signal-to-noise ratio and describes the amount of unwanted noise the amplifier will add to the signal. Consumer-grade amps will have a signal-to-noise ratio (SNR) of at least 80 dB. Higher-end amps will have an SNR of 100 dB or more. Audiophile amps will have an SNR of close to 120 dB.

Most of today's amplifiers are so-called Class-D amplifiers which means that they have higher power efficiency than Class-A or Class-AB amplifiers and for that reason waste little power as heat. Some of today’s mini amplifiers are no larger than a deck of cards. Though, when selecting a Class-D (digital) amplifier, be certain that the amplifier has low distortion and a high signal-to-noise ratio.


Related Blogs

Tagged with: • • •

Filed under: Satellite Radio Articles

Like this post? Subscribe to my RSS feed and get loads more!