As you might have already guessed, the best 4 Channel Amp are a bit different than others. There are a few differences to know about when shopping and just to have a better understanding.
The main difference is that 4 channel amps contain the 2nd pair of amplification stages to boost the input signal and drive speakers.
Just like standard 2-channel amps, they contain a special section that steps up a vehicle’s 12V supply to deliver a higher one (often around positive and negative 28 volts or so)
That’s necessary to provide sufficient power that can drive your component speakers or highs and mids at a better volume with low distortion. For example, car stereos can only use about 12V to drive speakers, resulting a lower power that distorts easily.
According to Ohms law more power requires a higher voltage and that’s exactly what powerful car amps are designed to use.
4 channel amps are also a bit more compact in size as the additional 2 channels take up a bit less space than 2 separate 2-channel amps used separately.
In order to work in more applications, some 4 channel amps feature a 2/4 channel input switch. This means that if you have a source unit with only 2 RCA jack outputs you can still get 4 channels of sound to use from the amp.
Additionally, most 4 channel amps sold today are bridgeable, meaning that each pair of channels can be used to drive a single speaker for more power than each individual channel can provide. Because of this, they offer more flexibility for custom car audio systems than a single 2-channel amplifier can.
Some also feature different options like a bass boost for the rear channels (normally #3 & 4). The specific features you’ll find vary from brand to brand and model to model.
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