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Picking The Best Audio Amplifier For Your Speakers

Selecting the perfect audio amplifier can be overwhelming given the huge number of different types and technologies. I will clarify some essential amplifier vocabulary and assist you choose the right model regardless of what your particular application may be.

Audio amplifiers are the main connection between your source such as a DVD or Blu-Ray player and your speakers. An amplifier will convert the relatively weak source audio into a signal strong sufficient to drive your loudspeakers.

Even though some audio sources have already a built-in amplifier, a separate amplifier gives you more freedom for picking the model that best complements your speakers. There are some mini amplifier models available. These types are small enough to hide practically anywhere.

Many people will take a look at amplifier wattage first when choosing an amplifier. Output wattage is the level of energy the amplifier is able to deliver to the speakers. Driving low-sensitivity speakers (sensitivity is expressed in dB/W) calls for relatively high wattage. Also, driving outdoor speakers or speakers in a large room will require higher amplifier power. Don't overdrive your speakers though since this will irreparably harm your speakers.

Still, a 20 to 50 Watt amplifier will give you more than sufficient power in many situations so don't be overly concerned about the rated amplifier wattage.

Amplifier wattage is given either as rms or continuous power which shows how much power the amplifier can deliver continuously or as maximum or peak power which shows how much power the amp can supply for small periods of time. Most people will take a look at the rms power value whilst picking an amplifier. On the other hand, music signals are anything but continuous. As a result selecting an amp that has adequate peak power handling is just as crucial.

Audio quality is just as significant as having enough audio power and for that reason you should also take a look at figures such as total harmonic distortion or THD. Every amplifier will introduce some imperfections into the audio signal which is referred to as distortion and expressed in percent or dB. The level of distortion varies between amplifier types. A smaller distortion means higher audio quality. Audiophile-grade amps will have distortion figures of at most 0.05% whilst consumer-grade amps have distortion of up to 10%.

An additional specification is known as signal-to-noise ratio. This figure specifies how much undesired components such as hum and noise the amplifier will add to the audio 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.

The bulk of today’s amplifiers are based on a technology known as Class-D which offers higher energy efficiency than amplifiers based an Class-A or Class-AB technologies. High efficiency means that little power is wasted as heat which can make the amplifier fairly small. Class-A and Class-AB amplifiers demand a fair amount of heat sinking and therefore are usually fairly large and heavy. In contrast, amplifiers based on the Class-D technology are small and lightweight. Some of today's smallest mini amplifiers are no larger than a deck of cards. Class-D type amplifiers frequently have higher distortion and a lower signal-to-noise ratio than Class-A or Class-AB amplifiers. Some latest digital amplifier models, however, come very close to the audio quality of analog amps. Make sure that the amp has low distortion and a high SNR if you choose a Class-D amp.