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Video: car amplifier channels

How many channels do I need for my amp?


Ken Nail

Ken Nail has written about car audio for Crutchfield since 2003, after four years as Crutchfield Sales Advisor, and 10 years as a music teacher. He's an avid music listener, whose favorites are classical and film music. When not chained to a desk, Ken spends most of his time training for triathlons and marathons, and likes getting outside for backpacking, downhill skiing, and bicycle touring. He attended West Virginia University, where he received a Master's Degree in Music Performance and a Bachelor's Degree in History.

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Zak Billmeier

Zak Billmeier grew up in southern Vermont and coastal Maine. After graduating from Mary Washington College with a Geography degree he still isn't sure quite what to do with, he eventually settled in the mountains of Central Virginia. He spends his free time chasing his daughter around, taking pictures, gardening and cooking. He joined Crutchfield's car A/V writing team in 2007 and is now a lead producer on our video team.

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One of the first steps in choosing an amplifier for your car audio system is to decide how you intend to use the amplifier, and thus how many channels it should have. This short video gives you a quick overview to help answer that question.

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Video Transcript

Zak: When you're shopping for an amplifier the first question to ask yourself is,
"How am I going to use it?"
"Am I going to power a sub or two subs?"
"One pair or two pairs of speakers, or maybe subs and speakers?"

Knowing this helps you make the first decision: which type of amp to buy based on how many output channels and how much power you need. So then let's take a look at the different types of amplifiers based on the number of output channels they have. Mono amps have one output channel. They're usually used to power subwoofers. And depending on the amp and the impedance of the subwoofers you can connect one, two or even more subs to just one mono amp.

Ken: 2-channel amps offer more versatility. You can use the two output channels to power a pair of speakers like the ones in your car's front doors. And most 2-channel amps can also be bridged. This combines the output of the two channels into a single channel. It's a great way to power a subwoofer.

Zak: 4-channel amps give you the most options. They're perfect for powering a couple pairs of speakers. You can also enjoy the best of both worlds by using two of the amp's channels to power a pair of full-range speakers in the front of the car while bridging the output of the other two channels to drive a sub. You'll get clean highs and powerful lows out of one package.

Amplifiers don't stop at four channels though. 5-channel amps let you power your entire system with just one amplifier. They have four channels for powering your front and rear speakers and a fifth, higher-powered channel for powering your subwoofers. Plus, a 5-channel amp takes up less space and it's easier to install than two separate amplifiers. A 5-channel amp is a good investment if you want to build a system that has a lot of flexibility and room to grow.

Ken: To see all the amps we carry go to and be sure to check out which wiring kits we recommend.

Zak: To learn more about choosing the right amplifier, go to

Ken: And for personal, one-on-one help, call 1-800-555-9408.

  • Miguel Ibarra from warner robins

    Posted on 8/28/2015 11:15:57 AM

    Ok well I hooked up my amp and remote wire and everything. But wen I turn the car on and plug in my aux cord it doesn't work or my usb The speaker will only work with the radio nothing else. Do u know how I can fix that?

  • Buck Pomerantz from Crutchfield

    Posted on 8/28/2015 1:55:03 PM

    Miguel, If you bought your amplifier at Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • John from Cincinnati

    Posted on 12/20/2015 2:32:18 PM

    What's the best way to add a center channel

  • Buck Pomerantz from Crutchfield

    Posted on 12/21/2015 3:53:17 PM

    John, Making a center channel in a car system isn't as easy as hooking a speaker up to both right and left channels. A signal processor is needed to either combine the left and right signals together, or create a true center channel consisting of only the signal that is common to both left and right channels. Some people build home-made resister networks that let them safely run a center channel speaker from the right and left speaker wires. Digital signal processors with assignable inputs and outputs can sum the signals to use for a center channel. But I don't know of any presently available device that can create a true center channel signal in a car system. I think the Audio Control ESP-3 and the JBL MS-8 processors did, but they're discontinued and not so easy to find.