Buying the Best Audio Amplifiers for Your Needs

How do audio power amplifiers work

Audio amplifiers (audio amps or power amps) are electronic devices that increase the strength of sound signals or voltage passing through them. They amplify low-power audio signals to certain levels that are suitable for driving loudspeakers in a home audio system or a studio.

Technically speaking, audio amplifiers are made up of circuits that allow small input audio signals to control much larger signals through semiconductor junctions or grids of a tube, using them as flow adjusters for the electrons passing through higher-voltage devices.

They continually adjust output according to the signals or voltage coming in to make larger, but undistorted, versions of those signals.

Audio amplifiers are found in many types of sound systems and audio instruments used by a wide range of professionals, from podcasters and voice actors to musicians and sound producers/engineers.

How to match the right audio power amplifier to speakers

When matching an audio amplifier to a speaker system, you should choose an amplifier that can deliver power that is equal to twice the program rating of your speakers.

So, if you have a speaker with 8 ohms of nominal impedance and 350 watts of power rating, then you should at least use an amplifier that can produce 700 watts into an 8-ohm load.

If you are using a pair of stereo speakers, then you should also use an amp that can produce 700 watts per channel into 8 ohms.

Aside from impedance and power rating, it is also important to consider the headroom when choosing an audio amplifier. In simple terms, headroom is the difference between an amp’s normal operating level and the maximum level it can pass without distorting.

Music has a wide array of dynamic ranges, and without the right headroom, your speakers would produce a distorted sound too frequently.

Enough headroom ensures that only clean, undistorted power gets to your speakers.

On the other hand, using an audio amplifier with less power can damage your speaker or your entire sound system.

What to look for in an audio power amplifier

So, how do you choose the right audio amplifier for your home audio system or studio setup?

Here are the most important aspects to consider:

How to determine audio power amplifiers for loudspeaker loads

To determine which amp to choose for your speaker loads, you should know its resistance—how much power it allows to flow.

In most cases, audio amplifiers are commonly designed to work with 4, 8, or 16 ohms of resistance. To get optimum performance from your audio system, you should make sure your speaker’s total ohm load exactly matches with the amplifier.

Remember that if the impedance is too high, the power delivered to the speakers is reduced. If the impedance is too low, on the other hand, the power delivered to the speakers is higher, which can overload the speakers and damage the amp.

To keep things as simple as possible when using audio amplifiers, you can put enclosures of the same impedance in a “parallel” circuit. By doing so, you only have to divide impedance by the number of speakers you are using.

For example, if you are using 4 speakers with a total rating of 16 ohms, you just have to divide 16 by 4, which equals to 4 ohms. Now, you will know which audio amplifiers with the right impedance to get.

Here’s a reference guide for commonly used parallel loads:

• 2 16-ohm speakers = 8 ohms
• 2 8-ohm speakers = 4 ohms
• 2 4-ohm speakers = 2 ohms
• 3 16-ohm speakers = 5.33 ohms
• 3 8-ohm speakers = 2.67 ohms
• 3 4-ohm speakers = 1.3 ohms
• 4 16-ohm speakers = 4 ohms
• 4 8-ohm speakers = 2 ohms
• 4 4-ohm speakers = 1 ohms

What can you use as a source for an audio power amplifier

Most audio amplifiers accept any line-level input signals/sources and basically have 2 references:

1. -10dBV, which is usually found on laptops, CD players, mobile phones, and other consumer devices
2. higher-voltage +4dBU, which is used on preamps, audio interfaces, mixing boards, D/A converters, and other audio equipment used in home audio systems and studios

When choosing a source, keep in mind that different device outputs have slightly different levels from each other.

To avoid any problem, do not directly connect something that is not at line-level to an amplifier. This can be a musical or audio instrument without a preamp or a high-power output from another amplifier.

While most audio amplifiers are designed to accept input signals well beyond the +4dBU reference, you would still not want to do this on purpose. A piece of audio equipment is specifically designed for optimal performance based on a corresponding reference level with a good amount of headroom.

Consult 3D HD Gear

Properly matching audio amplifiers to a set of loudspeakers is a very important step to getting high-quality sound. If you are not sure about which amp to get, with all the many options available, the best thing to do is talk to the experts here at 3D HD Gear.

We are here to walk you through our great collection of audio amplifiers and determine which one is best suited to your needs.

So, don’t hesitate to give us a call!