Stereo amp installation

Strip the insulation off the end of the power wire that leads into the passenger compartment, and connect it to the other end of the fuse holder. When powering multiple amplifiers, you run a single heavy-gauge power cable from your battery to a distribution block , and then connect a lighter-gauge cable from the block to each amplifier.

This arrangement minimizes potential noise problems and keeps your installation looking neat. Make sure the main power cable is thick enough that it can handle the total current draw of all the amplifiers.

Check out our amplifier wiring diagram to see how the wiring gets connected in a typical 2-amp system. Attach the power cable to the positive battery terminal not directly to the battery post itself.

For top-mounted battery posts, the most common way to do this is to crimp a ring terminal onto the end of the power cable many cables in wiring kits come with it already attached.

Remove the battery terminal's nut, slip the power cable's ring over the bolt that secures the battery terminal to the battery post, and replace the nut. For GM vehicles with a side-mount post, we offer terminal adapters that work nicely.

A wire loom provides added protection for your wire against the high heat inside the engine compartment. If your kit includes a wire loom, thread it over the power cable until it reaches the firewall and cut to fit. Thread another piece over the short power wire running from the fuse holder to the battery.

As near to the amplifier's location as possible, find a bolt to your vehicle's metal frame to use for ground. If you can't find a convenient ground screw or bolt, drill a hole for one — be careful not to drill into any wiring, the gas tank, or a gas or brake line. Crimp a ring terminal usually included with the amp kit to the short piece of ground cable also in the kit. Scrape away any paint and clean the bolt location thoroughly, and then bolt the terminal tightly to the vehicle's metal chassis so the ground connection will be bare metal to bare metal.

Use a lock washer, a star washer, extra screws, and any other technique or device that'll keep this connection tight, clean, and electrically conducting. Many people even coat the final connection with silicone caulk to prevent corrosion. Improper or loose grounding is the 1 cause of amplifier problems. The turn-on wire also called the remote wire is located behind the stereo. On aftermarket stereos, it's usually a blue and white wire. The remote wire will "tell" your amplifier to turn on whenever the stereo is powered up usually, whenever the vehicle is turned on.

You'll have to remove the stereo to get to this wire. Locate the remote turn-on lead behind your radio usually a blue and white wire , and connect the turn-on lead from your amplifier wiring kit to it. Strip the insulation off a small section of this wire coming from the radio and the turn-on lead that came with your wiring kit and connect them together via solder, a crimp connector, or a Posi-Connector.

If, like a factory radio, your radio doesn't have a remote turn-on output, then you can get the turn-on signal from your vehicle's fuse box. Because of its low current demand, you can connect your turn-on lead to almost any fused output terminal, like the one for the radio itself for instance, as long as it only powers up when the vehicle's on.

You'll need to route the turn-on lead to your amplifier through the car's body — it's often easiest to route the turn-on wire with the RCA cables next step but you can also route it with the power wire after it passes through the firewall. The power and RCA cables should run on opposite sides of the vehicle, to reduce noise — but it won't matter for the turn-on lead's low current. Route the patch cables to the opposite side of the vehicle from the power cable.

It's important to separate the patch cables from the power wires as much as possible to avoid potential noise problems.

Now you can partially re-install the radio in the dash. Avoid completely re-installing it if you can, in case you need to fix a problem later. If you're using a factory radio with no RCA outputs, you can get your amplifier's input signals from the factory speaker wiring.

The speakers will be getting their signal from the new amplifier — which leaves the radio's outputs available to use for the amp's inputs. There are two ways to do this: get a line output converter LOC that'll adjust the speaker-level signal for your amp's input, or get an amplifier with speaker-level inputs.

You cut the factory speaker wires behind the radio, and connect the wires coming from the radio to your LOC or amp's inputs. Learn more about line output converters. Now you have to provide a way for the music to get from your new amp to the speakers.

The best way to do that is to run a new speaker wire from each amplifier output to each speaker. Use or gauge wire for speakers, or gauge for subwoofers. Speaker-level signals are not very prone to picking up interference, so it's okay to run your speaker wires near power cables.

Running wires is all about finding the best path. Here, we're running a bundle of speaker wires across the backseat to the amp in the trunk. You'll have to run each wire for your door speakers through the rubber gasket or boot around the hinge, to protect the wires from the weather or from getting pinched in the door.

There may be a Molex plug or a similar obstruction blocking the way, but you can usually find a place to drill a hole through it big enough to fit your wire through. Disconnect or cut the factory speaker wires and connect the new wires directly to each speaker terminal. It is important that you keep the polarity of your speaker wiring straight.

This means that each positive terminal of the amp connects to a positive terminal of a speaker — and the same goes for the negative terminals. This ensures that your speakers will operate in mechanical phase — all the speaker cones moving the same direction with the same kind of signal — and will sound balanced when playing together.

The positive and negative terminals of each speaker should be labeled, but if not, the positive terminal will usually be wider than the negative terminal. You cut each speaker wire from the receiver's harness and reconnect it to a speaker wire coming from the amp. Then, the signal can flow from the amp to the speakers by way of the vehicle's original factory wiring.

This technique will work fine in systems with up to 75 watts RMS of power per channel — but for more powerful systems it would be better to run new speaker wire directly from the amp to each speaker.

Check out How to connect an amplifier to a factory stereo to see how this can be done. Neatly drape or trim each wire and connect it to the amp. Make gentle curves with the wires, not sharp bends that could pinch. Many people cut small slits in their vehicle's carpeting and run their wires underneath, for stealthy installations that look factory-neat.

A wiring snake comes in handy for this. Tape your wires to the snake, fish it under and through to where you want your wires to go, and pull them on through. RCA cables routed through slits in the vehicle's carpet, and connected to the amplifier's signal inputs. Check all of your wiring, from the battery and receiver to the amp and speakers, making sure every connection is tight and secure with no stray wire strands laying out that could cause a short circuit. Especially, check that the ground connection is tight and secure.

Set all the amplifier's gains to minimum, and turn off all the filters and any bass boost or EQ it may have. See that the main fuse is properly installed in its holder. Then, reconnect your car's negative battery cable.

Turn on your car, then turn on the radio. Verify that the amplifier powered up there'll probably be an indicator light on it somewhere. Play some music and turn the volume up just loud enough to hear. If everything sounds right, you can finish re-installing the stereo and all your vehicle's paneling, and then move ahead to step Setting your amplifier's gain, or input sensitivity, matches the amp's input level with the receiver's output level, resulting in maximum distortion-free music and minimum background noise.

For a detailed explanation of how to do this, read our article about setting the gains on a 4-channel amplifier. Usually, once you've installed your amp, you can turn on the stereo and immediately enjoy all the extra power and detail in your music. But sometimes things just don't work like we expect them to right from the start.

If this happens to you, don't get stressed out too much. Read our article about troubleshooting your amp installation for help with finding and solving the most common problems. Your best first step is to call Crutchfield and talk to an Advisor about what your amplifier will need. They'll make sure you get all the necessary hardware and accessories for a successful and satisfying installation.

And remember, anything you buy from Crutchfield comes with free lifetime tech support. Just click on "Contact Us" at the top of this page for the toll-free number and other methods of contacting us. My current set up is using a factory installed Rockford Fosgate 10 speaker system in a Nissan Titan with an aftermarket HU.

I'm wanting to put in a 4 X amp and upgrade the lower door speakers. Is it okay to continue to use the factory Fosgate amp for the 3 dash and upper door speakers while using the RCA outputs from the HU to send signal to the amp for the 4 lower door speakers? Someone gave me a Jensen 2-channel amp to put with my 2 Kenwood Kfc-wps subs and I don't think the amp will push the 2 subs. Suggested edit. No need to display this. Fairly common knowledge, but still Specify which terminal on the battery to connect the power cable to.

So I installed a jvs assassin watt amp to run 6x9. Problem is only bass no highs. What is wrong. I will be replacing a stock head unit of a Ford f with a Kenwood head unit. Truck has an after market Alpine amp installed years ago.

What needs to be done to use your ready made wire harness and SWC that I have ordered from Crutchfield along with the Kenwood? I am installing an older 45 watt per channel 80 max two-channel amp in the back of my year-old car and running an 8-gauge wire for it. My question is: do I need also need an 8-gauge fuse holder at the battery connection?

I have one, but it is huge. And since the amplifier only requires a amp fuse, it looks like overkill. A 10 or gauge fuse holder would fit in the space near the battery better. But always a but! I don't want to choke down the 8-gauge wire at the very beginning of the ft run. I am using the 8-gauge to future proof the install in case I need to install a newer, more powerful amp at some point.

Head has 2 line out Jack's, amp has 4 line ins. I'm trying to run 4 speakers from the amp. I tried splitters but the out put is weak. It's a jensen xda94rb amp, the control app is worthless. Much stress, please help. Installing on a motorcycle. Simple enough for the power wire, and ground wire. However, my ACC wire on the bike is connected to a 2 prong plug. One side goes to where it needs to go to give power when the key is turned on, the other side goes to ground If the sound gets muddy when you turn it up, you need the added power of an amplifier.

You probably know the difference in sound between your TV speakers and a home theater system. An amplifier in your vehicle can make that kind of difference. You'll hear a bigger, fuller sound, with more detail and greater impact, especially if you've installed better speakers in your vehicle.

The first consideration is how many speakers you'll be powering and how much power each speaker will handle. Once you know that, you'll know how many amplifier channels you'll need and how much power you'll want. Yes, you can, as long as you have a basic knowledge of electronics and you're handy with tools. You'll have to run a power wire from your vehicle's battery back to your amp's location, and then a ground wire from the amp to your vehicle's chassis.

It's important to do the job correctly so you don't damage your vehicle. Our Tech Support people can help you if any issues come up. Check your speakers or sub to see how much power they can handle in terms of "watts RMS. Speakers are more forgiving, so you don't always have to max them out, although more power always sounds better. The easy answer is "one speaker per channel.

There are plenty of exceptions to this rule, so contact an Advisor to get the best advice for your situation. How much power and how many channels do your car speakers need? This guide will help you choose the right amplifier for your car's sound system. Check out this overview of a typical installation to see the steps involved when you install an amplifier in your vehicle.

Where should I mount it? What wiring do I need? What size fuse and power wire? These wiring diagrams illustrate how amplifiers connect to your audio system, which will make it easier to shop for the gear you need for the system of your dreams. Car amplifier audio terms - like watts, volts, and efficiency - are explained. Confused about wiring your subs and picking the right amplifier?

Crutchfield will get you on the fast track to big bass with this simple guide. You need to set your amplifiers gain correctly in order to enjoy your musics full range of dynamics hearing all the notes clearly, whether loud or soft.

Here's a method for setting amp gain fast and accurately using test tones. There are many ways to connect subwoofers to an amplifier. Our wiring diagrams will help you find the best way to wire your subs and amps so you'll get the best performance out of your gear. What size of wire should you should use when installing an amplifier?

Use our handy wire gauge chart to find out. For free personalized advice, call Our Advisors have listened to most of the speakers we carry, and can help you make the best choice for your system.

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In-dash stereos are very limited in how much power they can produce. The result is cleaner sound, less distortion, and great volume — you can crank your music even higher!

Just imagine driving down the road with the windows open and finally being able to blast the music you love. Planning ahead can mean the difference between getting your system going without major problems or having a frustrating time — or complete failure!

I always get organized and get my items together before I start a job. Planning ahead is very important. When it comes to installations, always plan to have more, rather than not enough, wire. This goes for speaker wire as well as RCA cables. A great example is this AmazonBasics foot roll. I recommend a foot roll for many installations with a 4 channel amp see why below. That means you need 2 ft rolls of wire. Or at the least, 1 ft roll and 1 50 ft roll.

Just pick up some good quality, well-made cables. Even a pair like these value-priced ones will be fine in most cases. Crimp tools are great for installing your amp and speaker wiring with professional results.

Crimp connectors are sold separately in many automotive parts stores or general stores and are very affordable. I recommend a few tools. If you shop carefully, you can avoid getting ripped off on tool prices. Never simply twist the wire together and wrap it in electrical tape. Always use a reliable connection. During warm weather, electrical tape adhesive can fail and the tape can come off of the wire. This exposes it to possible short circuits and potential damage to your radio or amp.

A test meter is often incredibly helpful when installing an amplifier. A basic but good budget model like this one at Amazon will work great. I recommend 18 ft length or more. Image of an aftermarket non-factory stereo showing the RCA jacks and speaker output wiring.

Either one can be used for getting a signal to an amp, but RCA jacks offer a better option. In order to install a 4 channel amp and drive all 4 speakers, in many cases, the biggest obstacle is getting a signal to the amp. One of the reasons why is that factory amplified systems often have non-standard wiring connections for the audio path and are prone to bad noise problems if you connect an amplifier without the proper adapter or wiring. Using this, you can run RCA cables to your amplifier.

Amplifiers with high-level speaker-level inputs like this one allow connecting to speaker wiring for a signal source. This avoids having to buy a separate adapter. Speaker level inputs are common on many 4 channel amplifiers. This then plugs into the speaker level input connector. A typical speaker-level input harness for a 4 channel amp. The wires are color-coded to make installation easier. This allows an easier upgrade for your stereo later, which is very common for people to do.

Using the line-level converter now will allow you to run RCA cables to your 4 channel amp to be used later if you buy a better stereo which will include RCA jacks, almost always. RCA cables line-level connections are the preferred way to connect a signal to your amp if you have that option.

RCA jacks on the rear of a Pioneer head unit. White represents the left channel white red represents the right. These are standard colors for audio outputs for both car and home stereo. If your stereo has RCA jacks, then congratulations. Things just got a bit easier — and potentially better sounding, too! You can also click here to view the. You can bundle speaker wire together with wire ties to keep it neat and make the installation easier.

Estimate the length of speaker wire you need to reach the amp or line level converter for each audio channel. To do so, run a length of wire from the radio to where the amp will be installed, then allow a little extra and enough length to run around curves and interior parts.

I recommend connecting to speaker-level outputs using crimp connectors and a crimp tool for a reliable, solid connection. Blue connectors are normally the right size for gauge wire.

A great resource for that is The12Volt. Cut the speaker wires, leaving enough length to move the wire and to have enough length to connect to the wire freely.

Then connect the 4 pairs of wire to the speaker wiring in the harness. Alternately, you can twist together wire, solder it, and carefully wrap it with electrical tape or use heat shrink tubing for insulation. If using speaker level inputs on your amp, also connect 4 pairs of wire to the output of the stereo. Once all wiring is connected, bundle it up using wire ties or, optionally, a little bit of electrical tape wrapped around.

Connecting RCA cables to an aftermarket non-original stereo for running to an amplifier. In some cases, white, clear, or some lighter color can be used to represent the left channel. If the front and rear RCA cables are the same, you might want to mark front and rear using some masking tape and a marker or pen. You may also have good luck finding an existing wire color from vehicle wiring diagrams I mentioned earlier or from a Google search.

You can connect a head unit car stereo with only 2 channels left and right to a 4 channel amp easily. Ordinarily, all you need is 2 RCA Y adapter cables. Likewise for the right channel. If using speaker level inputs on the amp, use the connections shown above. Never connect both types at the same time! Speaker-level outputs will damage RCA connections. As shown in the above diagram, you can connect 2 channels to a 4 channel amp using either the speaker level inputs wired in parallel or by using simple RCA adapter cables.

The sound quality will be exactly the same.