Choosing the Right Amplifier Doesn't Have to Be Hard


Choosing the right amplifier can be the difference between having a great sounding system and one that doesn't live up to a client's expectations. With so many options in the market, how do you choose the right amplifier for your application? Below are some general rules to help ensure you get the right amplifier to complete your installation properly.

HPA4202 Amplifier Front Panel

HPA4202 Power Amplifier Front Panel

The first thing is to start at the end of the signal chain. There are two important questions that need to be answered before selecting an amplifier. How many speakers are going to be connected to it and what will their power taps be set to? The answers to these questions change based on the exact application of the system and the size of the room. This is very important because it will successfully determine the power needed to run all of the speakers in the system. (Learn more about speaker placement and tap recommendations using our Speaker Placement Tool.) An amplifier with too little power output will fail if it is driven to push out more power than it is designed to deliver. An amplifier that has too much power isn't necessarily a problem. In fact, it may be beneficial for system expansion down the line, but a larger power amplifier will cost more money up front. A great rule of thumb for matching an amplifier to the speakers in the system is to add up all of the speaker taps that will be used and then add another 20% for headroom and target an amplifier that has that power capability. (Again, our Speaker Placement Tool makes this easy by providing suggested amplifier power required for the selected taps.) For example, a system may call for ten speakers all tapped at eight-watts for a total of eighty-watts. In this scenario, selecting an amplifier that can produce up to one hundred-watts of power would be the ideal choice.

Understanding how the amplifier will be used in the system and all of the inputs that will be connected to it is the next critical thing to understand before selecting an amplifier. The two most common types of amplifiers for commercial applications are power and mixer amplifiers. Power amplifiers generally have a single input meaning they can amplify the signal from a single source. This is a great choice if the amplifier is only going to be used for paging or background music, but not both. A power amplifier is also a great choice if the application calls for the use of a console mixer that multiple sources will connect to. The single output from the console would then connect to the amplifier. If more than one source is going to be used, or the application calls for more than one source to be used at a time, a mixer amplifier is the ideal solution. Mixer amplifiers are available with multiple common inputs including mic/line, RCA, or balanced 3.5mm. A common application for a mixer amplifier is the use of one input for background music and another for a paging microphone that can automatically lower the volume on the background music when a page is being made. These types of amplifiers are common in restaurants and retail applications.

AA200PHD Amplifier Rear Panel

AA200PHD Mixer Amplifier Rear Panel

A third important factor when considering an amplifier is how it handles heat. Amplifiers can generate a lot of internal heat when they are being used especially for extended periods of time. Installing an amplifier in an equipment rack that includes venting out the top will not fair well when mounted with another device directly above it as the heat will have no place to dissipate. Similarly, an amplifier that cools from the back to the front will struggle to cool itself if it is placed too close to a wall or other obstruction that restricts airflow to the back of the unit. Read the owners manual or features carefully to determine the cooling method of any amplifier to make sure it will work in the desired application.

A final consideration for choosing an amplifier is connectivity. Some amplifiers offer network connectivity, whether for basic monitoring capability or for more complex applications using CobraNet® or Dante network audio protocols. Additionally, some amplifiers include integrated digital signal processing software that can be accessed via a web browser that offers some signal processing power, eliminating the need to have secondary DSP hardware. Understanding what the end user wants to achieve with the system and reviewing what is available is key to choosing the perfect amplifier for the job. Remember that AtlasIED offers free design services so if you don't want to have to worry about selecting the right amplifier, let us do it for you. Visit our design assistance page to get started today.