One of the most vital questions when it comes to PA systems is, “How much power do I need?” This is one thing to consider when you are buying a power amp for your PA system. The power amp’s function is to boost the low-level signals coming from the mixer and broadcast them through the speakers.
Just how much power it creates is measured in watts. And you will want to make sure that you have enough wattage to fill the venue without you having to compromise the sound quality.
The amount of watts that you will need depends on a number of factors. And the most obvious of these factors is the performance location (room size, indoor or outdoor, acoustics). Although, there are some extra factors that might make the issue a bit more complex.
Let us take for instance, there is the efficiency of the speakers (that is, how much sound the speakers will produce per watt of power). There is also the idea of headroom (and this is how much power it takes to handle peaks without having to distort) and the desired volume of the music.
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Using speakers that come with average sensitivity, a rock band that is playing in a medium-sized club will need about 1,500 watts total power at a minimum, whereas a pop or jazz group might need between 250 – 270 watts. For a simple folk music band that performs in the same venue, that requirement can come down to as little 60 watts.
You should know that though these power estimates are mere generalizations; difficult performance spaces and music with a lot of dynamics can require substantially more power.
It is important to buy an amp with plenty of power to drive your speakers plus enough headroom to prevent distortion. When you are ready to purchase speakers, you will see that they have a power rating, and they are usually measured in watts. As a general rule of thumb, you will want an amp with twice the wattage of your speaker’s rated power handling to make sure you have a clean, undistorted signal that gets to your audience.