DIY – Amplifiers

Amplifiers are a key part of any audio system, however, when it comes to car audio what amp you’re using makes a huge difference.  Here’s a bit about amplifiers and info on the difference between wattage (Should you aim for a 1000 watt amp?  A 600 watt amp?), what a capacitor is, and how many channels you will need (6 channel amp?  What’s the best 5 channel amp?).

Amps and Wattage

Amps and Watts are like apples and oranges – 2 completely different things.  Watts measure how much power there is in a system while amps measure how much power is being used or drawn from a system.  What determines the actual impact of both is the voltage – how much power there is in the source.  For example, if you have a 12 volt source and there are 2 amps being drawn, then the wattage is 24.  If you have a 24 volt source and there are 2 amps being drawn, then the wattage is 48.

Which brings us to the question – what is the best amp for your sound system?  To answer that you need to work backward from your speaker specs.  There’s no point in getting a 1200 watt amp if your speakers can’t handle it.  Most speakers can handle 20 to 200 watts, though there are a few out there that can go much higher.

Amp Capacitor

Electricity is limited in a car, and a capacitor can help make sure there’s enough power when demand peaks.  There’s a lot going on that needs power in the car system itself, let alone the stereo system, so an external capacitor is often hooked up to the amplifier.  The capacitor pulls extra power from the battery when it is not needed, and then discharges that power when the music peaks and demands more power than the battery and alternator can give.


Determining how many channels you need in your amp is another situation where you need to work backward from your speaker specs.   Channels are circuits within the amplifier and they’re set to certain limits- impedance (ohms) and frequency.

People usually think that they need one channel per speaker in the system, but you can put as many speakers on a channel as you want, as long as you don’t exceed the power handling of the speakers/subs by more than 10%, and you don’t let the impedance fall below what the amp can handle.   Subwoofers are usually driven by a separate amp since they can’t tolerate higher frequencies.

Hopefully this post has cleared up a few questions about amps.  If you have additional questions, feel free to comment below and one of our BOSS Audio experts will chime in.