What are Amplifiers and How Do They Work?
At face value, what people know about amplifiers is that they make music louder.
Car Audio Amplifiers – What is an Amplifier?
Car Audio Amplifiers – How Does an Amplifier Work?
This is where things get slightly more technical, but we don't need to dive-in too deeply here. There are two types of signals: output signals and input signals. As you might have gathered, input signals feed information into a device (like an amplifier) and they generally originate from the receiver in your car, at which point, they are an output signal.
The role of a car audio amplifier is to process a lower wattage input signal, received from your receiver or other audio source, Increase it's power x however many channels your amplifier has (hopefully also improving it at the same time) then distribute the new more powerful signal to your (optional) Digital Signal Processor, then your speakers.
The output - input process repeats as the signal makes it's way through your sound system. A simple example of that is: Your 'CAR RECEIVER' sends music wrapped up in a signal, (output) Your 'AMPLIFIER' receives that signal (input) processes it and sends it (output) to your 'SPEAKERS'. Your speakers recognise the signal as input. As more components are added to your system the output / input process continues.
Car Audio Amplifiers – How Many Channels Should My Amp Have? How Much Power Do I Need for my speakers and Subwoofer?
How big does my amplifier need to be? That's pretty simple. You need something that will fit the space you have available.
How many channels do I need? That could be as simple as, how many channels do I want. But there is a bit more to it. Most, if not all car audio receivers / head units are generally 4 channels, plus a sub out. (Depends on the receiver) consisting of a Front Left, Front Right and Rear Left, Rear Right and maybe a sub out. If your car is fitted with front and rear speakers and you want to take advantage of that, then you are looking for a four channel amplifier. then a two-channel amp should suit you just fine. However, if those two speakers in the back of your car are valuable to your listening experience, then you’ll want to go with a four-channel amp. The more channels you have on your amp, the more options you give yourself.
Regarding output power for subwoofers. Different subwoofers require different amounts of power. If all you’re using is the vehicle’s factory system, then 50 to 200 watts RMS will do just fine. For your speakers, about 50 watts RMS per channel allows for ample volume. So you should plan on around 250 – 500 watts RMS for the bass portion of that. For a per channel system that requires 100 watts RMS or more you’ll want to plan on at least 1,000 watts RMS for your subwoofer. Always make sure that your sub’s top RMS level is equal to or greater than your amp’s top RMS level.