In this post we are going to cover the basics of car audio. There are many things that go into a stereo setup, but they can be broken down into their basic components:

Source

The source is where your music comes from. This can be in the form of a CD, mp3 player, cell phone, etc. Basically what the music is stored on.

Signal Processor

For your music to play through the speakers, the signal first has to be processed. For CDs the signal processor is built into the CD player. For phones and mp3 players, the signal processor is usually built in to the phone/player itself.  A signal processor takes the digital signal from your source and transforms it into something the amplifier will understand so it can be turned into sound.

Amplifier

After the signal is processed, it is amplified by either an external amplifier or the radio. Most head units are both a signal processor and an amplifier in one. This makes it easy to install aftermarket radios into otherwise stock cars since most cars have a basic radio with an amplifier built in. So really a head unit does both of these steps.

You can also add an external amplifier for cleaner and/or louder sound. This takes the signal from the radio or other signal processor in more advanced setups and amplifies it before sending it to the speakers to produce sound.

Speakers

Finally, the amplified signal makes its way through the speakers in the form of sign waves which produces the sound you hear that we call music (some better than others).

Car Audio Basics: How Does My Car’s Stereo Work?

Most Factory Car Audio Systems

Most cars come with a basic all in one head unit that acts as the signal processor and amplifier that sends that signal straight to the speakers. Since the signal processor is built into the cheap head unit, you usually can’t get good quality sound out of the factory setup without adding fancy external processors.

Amplified Factory Systems

Amplified systems are meant to sound good from the factory, but most of the time they don’t, and this usually complicates things. The way these systems work is the head unit acts as the signal processor that sends that signal to an external amplifier then to the speakers. Since these are meant to sound better than the all-in-one head unit setups, they usually do once you start adding your own components as well. But in some cases they end up sounding worse and expensive signal processors come into play.

Car Audio Basics: Upgrading and Optimizing Your Car Audio System

First Steps

Start at the Source

When you are trying to get the best sound out of your system, you want to start at the source and work your way from there. The best speakers in the world will sound terrible if you are trying to

stream Pandora through them.

CDs or lossless music files are the way to go these days, although most head units still don’t support lossless files. I would say the lowest bit rate you should go on mp3s is 320kbps AAC. Most head units will support this format, and iPods support this format. Most head units have great iPod support. Win-win.

Also, it will be very hard if not impossible for most normal people to distinguish between this format and lossless. Especially in a car environment (terrible acoustics, road noise, etc).

Head Units

The most popular first upgrade is the radio itself, or head unit. This is for many different reasons: features, looks, customization, better processing, etc. Car companies use cheap parts to keep the cost of their cars down. It’s amazing how much difference a good head unit can make, especially when you can add features your car might not have come with in the process.

Features

Units like this new Pioneer AVIC-8000NEX (discontinued) fit most vehicles with the right parts and greatly improves the looks and functionality of your dash. DVD playback, smartphone compatibility, navigation, are all features you can have when adding an aftermarket head unit.

You can see how this is a popular first upgrade for your sound system. You can even add external monitors and sources such as headrest TVs or a backup camera. Adding an aftermarket radio also makes it easier to add external amplifiers.

Sound Quality

Not only do aftermarket radios offer better features, they usually offer better sound quality, too. Most stock head units have cheap DACs (digital to analog converters). When you upgrade your head unit, most of the time you are upgrading the DAC as well. Units like the Pioneer DEH-80PRS ($324 on Amazon with Prime shipping) offer three separate Burr-Brown DACS and 3 volt RCA outputs for the ultimate in sound quality.

Louder Sound

Aftermarket units also offer more power than stock head units (not stock amplified systems, though). Most factory radios have around 5-10 watts RMS per channel on their built in amplifiers. Most aftermarket radios offer around 15-18 watts RMS per channel (although they advertise 50W; this is a max power rating, though).

Subwoofers/Amplifiers

Subs are probably the next most popular upgrade whether it be for sound quality or SPL (sound pressure level, aka loud).

Sound Quality (SQ)

Subwoofers are not just to make loud boomy noises. They also greatly increase the sound quality in a few different ways.

One way they help with sound quality is they introduce low frequency sounds that most factory speakers or even aftermarket mid range drivers can’t reproduce clearly. This lets you hear low sounds that you couldn’t hear before that add depth and richness to your music.

Another way they help with SQ is take bass out of your mid range speakers. Most factory systems have full range speakers. This means the signal going to them consists of the very low frequencies and the very high frequencies that these speakers can’t produce. This makes them sound distorted when you try to play bass through them.

When you add a sub, you can set it to play the low frequencies only and set your other speakers to play only the frequencies higher than that. This allows each speaker to be within its sound reproduction range and makes everything much less distorted.

Sound Pressure Level (SPL)

Another popular use of subwoofers is to be loud. This is usually for people trying to show off or compete in SPL competitions. In these setups you usually have the biggest or most subs you can fit/afford with a lot of power going to them. These are the systems that go bump and wake your neighbors late at night.

Amplifiers

In order to add a sub, you have to have an amp to power it. Since head units usually only put out 50W max, you need to add a more powerful external amp to put out the higher power levels subs need since they are a much bigger driver than your typical 6.5″ speaker. Subs usually require at least 150W RMS to perform (depending on the driver).

Some people want to add a little bit of bass in a small package. Sub and amp combos like this Infinity Basslink ($230 on Amazon with Prime shipping) powered subwoofer have the amp built in and take up less room without sacrificing too much bass performance

Speakers/Amplifiers

The next upgrade step is usually the speakers, specifically the front. This can be done with or without adding another amp, but you will get much better performance in terms of quality and loudness with one. The front speakers come first because that is where the sound is being projected towards you, and setting up a good front stage can make it sound like a concert in your car. Rear speakers are usually just used for fill or not used at all when quality is your concern. For loudness, you’ll add all the speakers you can.

Coaxial Speakers

Coax speakers are the ones with the tweeter built into the center of the speaker like these Polk Audio db652‘s. This design allows for more simple installation than component speakers but still adds much better quality than factory speakers. These are a very popular choice due to being more inexpensive and easier/cheaper to install than component setups.

The tweeters are usually crossed over with the use of a capacitor which gives it a -6dB/octave slope at a fixed crossover point to block low frequencies from playing through, and damaging, the tweeter.

Component Speakers

Component speakers, or separates, are speaker setups that separate the tweeter from the mid range driver so the tweeter can be located to better improve sound quality. Since higher frequency sounds are easier to localize than low frequency sounds (hence why the sub is all the way in the trunk usually, the speakers are way down in the door panels, and the tweeters are up high), placing the tweeters closer to ear level and facing them at the driver raises the sound stage and greatly improves the sound quality.

Components usually come with an external crossover with a more advanced network than a single capacitor. These usually have a second or third order crossover set at a certain frequency offering steeper crossover slopes and usually consist of an L pad to dim the tweeters down a few dB to make them not as harsh.

Amplification

Speakers can be amplified with the head unit, but adding an external amp greatly increases output and sound quality. This is especially true when running components since the passive crossovers aren’t too  efficient and require the recommended RMS power to sound best.

Basically, if you can afford it, do it.

These are the basics of sound system upgrades. Depending on your budget you can do one or all of them to improve your sound.

Conclusion

Now that you know the car audio basics, hopefully you have a better idea how everything works together as a system. This should give you some ideas on what route to take when upgrading your car audio system.

Check out my previous blog posts here to get an idea of next steps such as proper speaker installation, what NOT to do, and recommended tools for DIY car audio.

Grounding car audio amplifiers improperly is probably the most common problem I’ve seen when an amp won’t power on or is having other issues.

A bad amp ground was the first problem I ever encountered on my first ever install.

I’ve thrown together some quick tips for you to try and prevent this problem. But I put this together pretty quick, so I may have forgotten something.

Before I tell you each method, remember you have to scrape away any paint and get to bare metal to have a good ground.

This is the most important part – you need BARE METAL!

Another thing to note is that ground wire length doesn’t have to be short like you’ve always been told. My theory is companies that sell amp kits just do this so that they can put a higher power rating on the label for their kits (there’s probably some other reason they do this, though.)

But remember, you have to take into account the length of the ground when sizing your wire. So the longer you make your ground, the bigger your power and ground wire need to be.

So here’s the main methods of grounding amplifiers that work pretty good:

Optimal Car Grounding Points for Grounding Amplifiers Properly

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1. Factory Amplifier Ground

The best way (and sometimes even the easiest) is to use a factory grounding point. This can be a factory amplifier ground wire or really any factory ground wire location.

Factory grounds usually have a little stud with a nut on them and some other grounds run to them.

It’s usually easier than you think to find a factory ground. They can be found under seats or in kick panels a lot of times.

2. Grounding Amplifiers through body metal or chassis with nut and bolt

This is the next best method, especially if you just want to use the short ground that came with your amp kit.

Scrape the paint. Drill a hole. Connect your ground with a ring terminal, nut, bolt, and lock washer.

Sometimes you may not be able to get to the bottom side of the grounding point and put a nut on it. Which leads me to the next methods.

3. Nutsert through body metal

You can also use a nutsert to create a threaded hole to screw your ground into.

This can work pretty good, but I’ve seen nutserts come loose before. So be sure to drill the right size hole and use a good quality nutsert.

4. Ground amp through body metal or chassis with a self tapping screw

Honestly, this is usually what I do when there isn’t a close factory ground. I use a short self tapping screw and a star lock washer. Sometimes I’ll put an extra screw or two on the sides or straight through the ring terminal.

You’ll hear a bunch of OCD people say this method sucks and is for lazy people.

I’ve used this method several times with no issues, though. And I’ve already admitted I’m lazy.

Be sure to use a lock washer. I’ve seen grounds come loose before, but I don’t think I’ve ever had an issue with a ground coming loose when using a lock washer.

5. Run amp ground wire to the battery

Note that grounding to the body on something like the aluminum F150s won’t work. You’ll need to run your wire to a factory ground point or to the battery.

If you are ever running both power and ground up to the battery, look into a marine power wire kit. They usually come with the same length power and ground wires (sometimes connected together). Just be sure the wire size is correct for the total length of power and ground for the current your amp pulls.

So pick whatever method you think will be best for your install. You can find all my recommended grounding parts below:

Click here to see Car Audio Advice’s recommendations for grounding components for grounding amplifiers correctly

Top 5 car audio tools every car audio installer should have in their toolbox

Obviously there are more than five car audio tools you need for installations. I’m assuming you have the basics such as drill, screwdriver, wrenches, etc.

These five tools are more specific to car audio and while not absolutely necessary, they will definitely make any install a breeze. And if you are serious about your installs, you will have these in your toolbox.

So here’s my list of the top 5 car audio tools:

This website contains endorsements for products and services which means when you click on a link that we recommend, we may receive a commission at no cost to you.

1. Car Audio Tool #1 – Crimpers/Wire Cutters

My crimpers are probably my most used tool when I am installing something.

(Part of that may be because I use them as a crimper, cutter, wire stripper, pry tool – pretty much anything I can use them for, I do.)

Here are a few reasons I love my crimpers so much:

• I use these Klein crimpers with the wire cutter on the end. So I can use them to cut wires, strip wires, cut tape off of wires, etc.

• I use butt connectors for all of my connections. If you were an early subscriber to my email list, you’ll know why I prefer crimped connections over soldered – but that’s a topic for another time. (Long story short, properly crimped connections are just as good or better in a car than soldered connections – and they’re quicker too.)

• These Klein crimpers are the best I’ve found. They just feel right.

• They’ve lasted me about 10 years so far and still work just as good as day 1.

Here’s a great video on how to make proper crimped connections: 

2. Car Audio Tool #2 – Panel Poppers

Panel poppers (or pry tools) are essential when removing interior trim.

Not much explanation needed here.

Take apart your car without damaging it. These trim tools from Harbor Freight are the best in the biz. They are also some of the cheapest.

I am currently on my third set but only because I lost the first one and the second set is finally starting to come apart after 10 years of hard use!

Another one I recommend is a thin tip metal pry tool. These are super thin and can get into tight spots.

Just be careful because they can mar the surface easier than the plastic ones.

3. Car Audio Tool #3 – Multimeter

Multimeters are one of the most useful tools an installer can have.

Multimeters have a ton of uses for car audio. A few of the most common uses are:

• Checking DC voltage to find power wires, test batteries or alternators, and and find switched power among others

• Checking resistance of speakers or ground points

• Using continuity mode to test wires or grounds

• Using AC voltage to set amp gains

• Troubleshooting almost anything in a car

Buying a multimeter won’t help you much unless you know how to use it. The video below should help you out.

4. Car Audio Tool #4 – Pick Tools

Pick tools are great for removing all the tiny little hard to get to things like screw covers behind door handles or certain pop clips.

I like these el cheapos from Harbor Freight. Not because they’re the best but because I’m cheap.

If you want something a little more robust or don’t have a Harbor Freight nearby, these will do the trick.

The rounded hook tool is great for pulling a certain wire out of a bundle for easier access.

5. Car Audio Tool #5 – Drill

Drills are necessary when drilling mounting holes for your equipment or drilling holes in the firewall to run power wire.

I prefer an impact driver for pretty much everything other than drilling holes. It makes removing screws easier and they are usually a little bit smaller. So they can fit in tight spaces.

So I recommend getting a set with both a normal drill and an impact driver.

The Milwaukee M12 is nice and small for those tight spaces. And it should be plenty powerful for most car audio uses.

Those are my recommendations for the MINIMUM car audio tools you need.

Obviously there are tons of tools out there. So if you want to see some of my other recommendations, check out my Amazon shop:

Car Audio Advice Amazon Store – Installation Tools

These aren’t really needed but will make your job much easier. If you are planning on installing more often, I’d recommend picking these up as well.

Click here for more of my favorite and most essential car audio tools.

More Info:

Installing a high-quality car audio system isn’t just about selecting the right speakers or subwoofers. The foundation of an exceptional sound experience lies in the tools and accessories used during the installation process. Whether you’re a professional installer or a car enthusiast embarking on a DIY project, having the best equipment at your disposal is crucial for achieving optimal sound quality. In this guide, we’ll explore the essential car audio tools and accessories that can transform your installation process and elevate your listening experience.

Why Quality Tools Matter in Car Audio Installation

When it comes to car audio installations, precision and efficiency are key. High-quality tools ensure that every component is installed correctly, reducing the risk of damage to your vehicle or audio equipment. Moreover, the right tools can save you time, making the installation process smoother and more enjoyable. Investing in top-notch equipment also means that your sound system will perform at its best, delivering clear, powerful audio that complements your driving experience.

Essential Car Audio Installation Tools

To achieve a flawless car audio setup, you’ll need a range of specialized tools. Here’s a rundown of the must-have equipment for any car audio installation project:

1. Wiring Tools

Proper wiring is the backbone of any car audio system. Without reliable connections, even the best components can falter. Essential wiring tools include:

• Wire Strippers: Precisely remove the insulation from wires without damaging the conductors.
• Crimping Tools: Securely attach connectors to wires, ensuring a stable electrical connection.
• Multimeter: Test voltage, current, and resistance to troubleshoot electrical issues.

Pro Tip: Choose tools with adjustable settings to accommodate various wire gauges and connector types.

2. Mounting Tools

Properly mounting speakers and other components ensures longevity and optimum performance. Key mounting tools include:

• Screwdrivers and Nut Drivers: Essential for assembling and securing components.
• Drill and Bits: For creating precise holes when installing custom mounts or brackets.
• Panel Removal Tools: Safely remove interior panels without causing damage.

3. Testing and Calibration Devices (Intermediate)

After installation, it’s crucial to test and calibrate your system to ensure it performs as intended. Useful devices include:

• Signal Generators: Provide audio signals for testing speaker response and system clarity.
• Oscilloscopes: Visualize electrical waveforms, helping to diagnose complex issues.
• Sound Level Meters: Measure the output levels to ensure balanced sound distribution.
• Audio Analyzers: Assess various aspects of audio performance, including frequency response and distortion.

4. Installation Accessories

Beyond the primary tools, several accessories can enhance your installation process:

• Cable Management Solutions: Keep wires organized and prevent tangling or interference.
• Heat Shrink Tubing: Protects exposed wire connections from moisture and abrasion.
• Adhesive Mounts and Velcro Strips: Secure components without damaging your vehicle’s interior.
• Anti-Vibration Mounts: Reduce noise and vibration for clearer sound quality.

Enhancement Tip: Investing in quality accessories can significantly improve the durability and aesthetics of your installation.

Best Equipment for Quality Installations

Achieving top-tier sound quality isn’t solely about the installation; the equipment you use plays a pivotal role. Here are some of the best tools and accessories to ensure your car audio system performs at its peak:

High-Precision Wire Strippers

Accurate stripping of wires is fundamental to creating reliable connections. Look for wire strippers that offer:

• Multiple Gauge Settings: Accommodate various wire sizes used in different components.
• Durable Construction: Ensure longevity with high-quality materials resistant to wear and tear.
• Ergonomic Design: Comfortable handles reduce hand fatigue during extensive installations.

Premium Crimping Tools

A strong crimp is essential for preventing electrical failures. Choose crimping tools that feature:

• Consistent Performance: Deliver uniform crimps every time, regardless of wire type.
• Interchangeable Dies: Adapt to different connector sizes and styles as needed.
• Safety Features: Protect against accidental injuries with built-in safety mechanisms.

Advanced Soldering Stations (if that’s your thing)

For those that prefer soldering (even though proper crimps are the way to go for automotive connections), look for soldering stations that offer:

• Temperature Control: Precisely manage heat to suit various solder types and wire gauges.
• Fast Heat-Up Times: Reduce waiting periods and increase efficiency.
• Safety Certifications: Ensure compliance with safety standards for worry-free operation.

Comprehensive Multimeters

A versatile multimeter is invaluable for diagnosing and troubleshooting electrical issues. Opt for models that include:

• Auto-Ranging Capabilities: Automatically detect the required measurement range for ease of use.
• High Accuracy: Provide precise readings to identify subtle electrical discrepancies.
• Durable Build: Resist drops and impacts typical in a workshop environment.

Enhancing Your Installation with the Right Accessories

Accessories are the unsung heroes of a successful car audio installation. They not only streamline the process but also contribute to the system’s overall performance and longevity. Consider incorporating the following into your toolkit:

Cable Management 

Keeping your wiring organized is essential for both functionality and aesthetics. Cable management typically includes:

• Zip Ties: Secure wires neatly along predefined paths.
• Cable Sleeves: Bundle multiple cables together, reducing clutter.
• Routing Clips: Attach wires to panels and structures without drilling.

Heat Shrink Tubing Set

Protect your connections and prevent short circuits with heat shrink tubing. A comprehensive set offers:

• Various Sizes: Fit different wire diameters and connection types.
• UV-Resistant Options: Provide added protection against environmental factors.
• Easy Application Tools: Simplify the heat-shrinking process for a professional finish.

Panel and Trim Removal Tools

Avoid damaging your vehicle’s interior with dedicated removal tools, which typically include:

• Soft-Tip Instruments: Prevent scratches and dents during panel removal.
• Flexible Picks: Navigate tight spaces and intricate panel designs.
• Comprehensive Toolkits: Provide all necessary tools in one convenient package.

Anti-Vibration Hardware

Reduce unwanted noise and vibrations in your audio system with specialized mounts and dampeners, such as:

• Rubber or Foam Mounts: Absorb vibrations from speakers and subwoofers.
• Isolating Brackets: Separate components from the vehicle’s frame to minimize resonance.
• Secure Fasteners: Ensure all mounts remain firmly in place during operation.

How Tools Elevate Your Car Audio Installation

At Car Audio Advice, we understand that the quality of your car audio installation is directly tied to the tools you use. That’s why we recommend a curated selection of the best car audio tools and accessories, designed to meet the needs of both professionals and enthusiasts. Here’s how the tools above make a difference:

Precision and Reliability

These tools are manufactured to the highest standards, ensuring precision in every cut, strip, and crimp. Reliable performance means fewer installation errors and a smoother workflow, allowing you to focus on creating the perfect sound system.

Durability and Longevity

Investing in our high-quality tools means you’re equipped to handle countless installations without wear or failure. Durable materials and robust construction provide a long-lasting solution, saving you money in the long run.

User-Friendly Designs

They prioritize ease of use, featuring ergonomic handles, intuitive controls, and clear instructions. This user-centric approach makes the installation process more enjoyable and less fatiguing, even during extensive projects.

Step-by-Step Installation Guide

Embarking on a car audio installation can seem daunting, but with the right tools and a clear plan, you can achieve professional results. Here’s a simplified step-by-step guide to help you through the process:

Step 1: Planning and Preparation

• Assess Your Vehicle: Determine the best locations for speakers, subwoofers, and other components.
• Gather Tools and Accessories: Ensure you have all necessary equipment on hand.
• Review Installation Manuals: Familiarize yourself with the specific requirements of your audio components.

Step 2: Removing Interior Panels

• Use Panel Removal Tools: Carefully detach dashboard panels and trim to access mounting areas.
• Label Components: Keep track of screws and parts to streamline reassembly.

Step 3: Wiring and Connections

• Run Cables Neatly: Use cable management solutions to prevent tangling and interference.
• Secure Connections: Employ crimping tools and soldering irons for durable electrical bonds.
• Test Connections: Use a multimeter to verify the integrity of your wiring before finalizing.

Step 4: Mounting Components

• Position Speakers and Subwoofers: Use mounting tools to ensure components are securely placed.
• Apply Sound Deadening Materials: Enhance acoustic performance by minimizing vibrations.
• Double-Check Alignments: Ensure all components are level and properly oriented.

Step 5: Testing and Calibration

• Power Up the System: Turn on your audio setup to check for functionality.
• Adjust Settings: Use testing devices to calibrate sound levels and balance.
• Fine-Tune Placement: Make minor adjustments to speaker positions for optimal sound distribution.

Step 6: Finalizing Installation

• Reattach Interior Panels: Secure all removed panels and trim, ensuring no gaps or loose parts.
• Organize Cables: Tidy up any remaining wires for a clean and professional look.
• Perform a Final Test: Listen to various audio tracks to confirm the system performs as expected.

Ready to Upgrade Your Car Audio Installation?

Don’t settle for anything less than the best. Equip yourself with top-quality tools and accessories and experience the difference in your car audio installations. Whether you’re enhancing an existing system or starting from scratch, these tools will help you achieve professional-grade results.

Frequently Asked Questions

What are the most essential tools for a beginner in car audio installation?

For beginners, the most essential tools include wire strippers, crimping tools, a multimeter, screwdrivers, and panel removal tools. These basics will cover most installation tasks and help you build a solid foundation for more advanced projects.

How can I ensure the best sound quality in my car audio system?

Achieving the best sound quality involves using high-quality components, meticulous installation practices, and proper calibration. Investing in reliable tools and accessories ensures that every connection is secure and that your system is balanced for optimal performance.

What makes these tools different from others on the market?

These are the tools I personally use and have great success with. Some of it is preference. 

Final Thoughts

A high-quality car audio installation is a blend of excellent components and the right tools. By equipping yourself with the best equipment and accessories, you can ensure a seamless installation process and enjoy a superior sound experience every time you hit the road. 

If you just want to get to wiring and don’t care about the technical stuff, click here to be brought to the subwoofer wiring diagrams page.

How to Wire Subs: Series and Parallel Wiring

Series

Series wiring for speakers means you are connecting the speakers like a chain. The positive terminal from one speaker connects to the negative terminal of the next speaker, then the positive of that speaker connects to the negative of the next speaker. You can do this with an infinite number of speakers. In this arrangement, if one part of the circuit is removed, nothing will work.

Series wiring will add the impedance of each speaker together, so for example: if you had three 2 Ohm speakers wired in series, the total impedance would be 6 Ohms. This will be explained in greater detail when I get to Ohm’s law.

For series wiring: Total Impedance = Sub Impedance x Total # of Subs

Parallel

Parallel wiring connects all of the positive terminals together and all of the negative terminals together. This means if part of the circuit goes out, all of the rest will still be connected, but the impedance will be affected.

Parallel wiring of speakers reduces the resistance seen by the amp, therefore making the amp work harder by pulling more current. Instead of adding all of the impedances together, the total impedance will be reduced further and further with each speaker added to the circuit. For example: if you wire (2) 4 Ohm subs together in parallel, you will get a total load of 2 Ohms.

For parallel wiring: Total Impedance = Sub Impedance / Total # of Subs, so if you have (4) 2 Ω SVC subs all wired in parallel, the total impedance will be 2 Ω / 4 subs = 0.5 Ω

Ohm’s Law 

Ohm’s law is the governing equation for all electrical circuits, and the equation is V = I x R where V=voltage, I=current, and R=resistance.

Voltage is constant for car audio (12V nominal, 14.4V with a running vehicle).

Resistance is constant (the total impedance your speakers are wired to).

Current will change depending on your impedance and the power your amp is capable of.

Rearrange the equation to read I = V / R.

This shows that if resistance is decreased, then the current the amp is pulling will increase. Therefore, the power output of the amplifier will increase because of the power equation P = V x I. Now you see why wiring subs to lower impedances will get more power out of your amp, and as a result and is why a lot of amps don’t like seeing too low of an Ohm load. A low ohm load will try to overpower the amp by pulling too much current.

This is a great Ohm’s Law chart to quickly see all the equations for power, current, voltage, and resistance:

Single vs. Dual Voice Coil 

The number of voice coils a subwoofer has determines your wiring options. Many people think DVC subs are more powerful than SVC or vice versa, but this is not the case. They make so many different versions of the same subs so you can get the total Ohm load you need no matter how many subs you plan on connecting together. A single DVC sub has two different wiring options right out of the box, whereas a SVC sub only has one.

Single Voice Coil (SVC)

Single voice coil subs are subwoofers that only have one voice coil. The impedance of a SVC sub will only be what that sub is rated at. For example, a single SVC 2 Ohm sub can only be wired to  2 Ohms.

Dual Voice Coil (DVC)

Dual voice coil subs have two voice coils. A single DVC sub can be wired to two different Ohm loads right out of the box by wiring it in either series or parallel. For example: a single 4 Ohm DVC sub can be wired to either 2 Ohms (parallel) or 8 Ohms (series). The Ohm rating on DVC subs is actually the rating per voice coil, so you cannot wire a 4 Ohm DVC sub to 4 Ohms.

How to Wire Subs to Desired Impedance

Now that you know what series wiring will raise total impedance and parallel will drop total impedance, I will show you how this is used in subwoofer wiring. Whenever you have (2) SVC subs of the same impedance, series wiring will always double that number, and parallel wiring will always half that number. Some math is needed for all other cases, especially when wiring multiple DVC subs together since you can have a mixture of series and parallel wiring in the same circuit.

For example: this circuit of two DVC 2 Ohm subs wired to a total load of 2 Ohms at the amp has the voice coils of each sub wired in series, but the two subs are then wired to each other in parallel. Wiring a DVC 2 Ohm sub in series gives you 4 Ohms. Then wiring two 4 Ohm subs in parallel will give you 2 Ohms. Hopefully that makes since.

Double check your final impedance with a multimeter after wiring before connecting your subs to the amp. I personally use this one from Amazon and it has worked great for me.

Below are some more diagrams for the most common wiring configurations. Post a comment or send an email if you don’t see the configuration you plan on wiring, and I can help you out. Here is a link to just the wiring diagrams for easier access: http://caraudioadvice.com/subwoofer-wiring-diagrams/

Subwoofer Wiring Diagrams – How to Wire Subs:

Single Voice Coil

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Two 2 Ω subs wired in series to 4 Ω

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Two 2 Ω subs wired in parallel to 1 Ω

Two 4 Ω subs wired in parallel to 2 Ω

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Dual Voice Coil

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One DVC 2 Ω sub wired in series to 4 Ω

Two DVC 2 Ω subs wired to 0.5 Ω

Two DVC 4 Ω subs wired to 1 Ω

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One DVC 2 Ω sub wired in parallel to 1 Ω

One DVC 4 Ω sub wired in parallel to 2 Ω

Two DVC 2 Ω subs wired to 2 Ω

Two DVC 4 Ω subs wired to 4 Ω

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We worked on so many F150s where I worked because they sound like complete garbage. After seeing the stock sound curve, I see why. Just see what a difference upgrading your system makes.

http://www.crutchfield.com/S-Gkldu8v0sQW/learn/car-stereo-proving-ground.html

Car audio amplifier installation kits, wiring kits, or amp kits, usually include all or most of the things you need to install your amp, but you don’t need the full kit if you already have most of what you need; you can go buy whatever you’re missing separately. It’s usually a lot cheaper to get a kit if starting from nothing. Also make sure the kit you buy includes what you need. For example: most kits only come with one set of RCAs. This is fine for a sub installation, but you will need another pair if you plan on doing 4 speakers on a 4 channel amp.

What do car audio amplifier kits include?

Car audio amplifier kits will include the wires, cables, fuse holders, and connectors you need to install your amp. Some include more pieces than others. This 4 gauge Scosche Vector series OFC amp kit  includes everything you need to get your system hooked up and sounding good. You can get cheaper kits, but the wires won’t be true AWG size, will most likely be copper clad aluminum (CCA), won’t carry current as well as name brand pure copper kits, and will have cheap RCAs.

It’s definitely worth the extra price to upgrade to a high quality kit like the Scosche Vector Series. When looking for a pure copper amp kit, some companies will call it 100% oxygen free copper, pure copper, or OFC. These provide the best conductivity and least resistance compared to CCA.

CCA wire can be used, too, but will be a little larger gauge and from my experience, corrodes faster. Using high quality connections and proper crimping techniques help with that, though.

Car Audio Amplifier Kits include the following:

Power Wire

The Power Wire will be the longer of the two thick wires in your kit. It runs from your battery to your amp. See the chart below or calculator (click here) to determine the power and ground wire size you need for your installation.

Ground Wire

The Ground Wire will be the shorter of the two thick wires, usually less than 3 feet.  The ground wires goes from your amp to the chassis or body of your car or back to the battery. Be sure to take the Ground Wire length into account in your wire size calculations, especially if you run the ground back to the battery with the Power Wire.

Remote Wire

The Remote Wire is the long single (primary) wire in the kit, usually blue. This wire runs from a switched 12V source, like the remote turn on wire on the back of aftermarket radios, to your amp.

Speaker Wire

Speaker Wire is the wire that is actually two wires together. Obviously this goes from your amp to your speakers, one side to positive, one side to negative. Some kits do not include speaker wire. KnuKonceptz makes a good speaker wire at a great price.

RCA Cable(s)

The RCAs are signal cables that run from the output on the back of your head unit, or low level converter (more on that later), to the input on the amp. These probably vary more than wire quality does. You don’t want to skimp on RCAs or you could possibly get engine noise or other signal quality problems. Use high quality RCAs like the Scosche Delta Series here.

Fuse Holder and Fuse

The Fuse protects your car, battery, and amp from getting fried if something goes wrong (actually it protects the wire itself, so the fuse rating in your amp kit can be compared to the fuse rating on your amp to determine if the amp kit will work for you). ALWAYS install the Fuse Holder and Fuse and as close to the battery as possible, usually no more than 18″.

Various Connectors and Terminals

Most kits will come with wire connectors and terminals so you can connect the wires where they need to go. A lot of amps don’t require special connectors, so these may not be used for your install.

How to pick what kit you need

Amp kits are sized by the power and ground wire. For example, if you buy an 8 gauge amp kit, the power and ground wire will be 8 gauge. The speaker wires are usually 12 AWG or less, and the remote wire is usually 18 AWG.

The chart below shows the basic wire size you need based on your power requirements assuming the kits you are looking at are a good brand with true AWG copper wire:

Note that you need to use the total length of your power AND ground wire for the length measurement.

How to Use the Chart and Calculate Wire Size

Just match the max amperage or fuse rating on your amp to the amperage on the chart, find out how long your wire is going to be, and you can find out what size wire you need. Use the general equations below to determine the current your amplifier will pull.

For a Class D amp (assumes 75% amp efficiency and 13.8 volts): 

\begin {aligned}
Amps={Total \> RMS \> Power \above {2pt} 0.75 \> x \> 13.8 \>VDC}
\end {aligned}

For a Class AB amp (assumes 50% amp efficiency and 13.8 volts):  

Amps={Total \> RMS \> Power \above {2pt} 0.50 \> x \> 13.8 \>VDC}

You can also find a calculator here that will tell you the minimum wire size needed for your installation.

Jump up a wire gauge size if you are ever unsure, are going with a cheap unknown amp kit, or if you go with CCA instead of OFC wire.

It’s recommended to go up two wire sizes from what the chart above shows if you use CCA in order to achieve less resistance. You can’t go wrong by getting bigger wire (smaller gauge) just don’t ever get smaller than recommended. The wire will pull more current than it’s designed for and possibly cause a fire if you use a wire that is too small. The inline fuse will blow in most cases, and if that happens, don’t swap it out for a bigger one! Fix the issue, and upgrade the wiring.

Many people like to save money by installing their parts themselves. It can also be fun and a great way to make sure it is done right. With this guide, I will explain how to install an amp. Whether it’s for subs or door speakers, the connections are still the same.

What You’ll Need

• Amp (duh)
• Subs/speakers
• Wiring Kit
• Aftermarket head unit or a line out converter to install with the factory radio

Amp/Speakers
The basics of amps and speakers can be found in Car Audio Basics and Basics to Upgrading Your System. If you have questions about how to match your amp and speakers, check out How to Select and Match Subs and Bass Amps. I will be doing a section soon on how to match amps with other speakers, but it is pretty much the same thing.

Wiring Kit
Now that you have your amp and speakers, it’s time to get the wires to hook everything up. For help selecting an amp kit, check out Selecting Amp Kits.

Aftermarket head unit or a line out converter 
In order to send a low level signal to the amp through the RCAs, you will need an aftermarket head unit or a line out converter. Aftermarket decks have RCA outputs built in (usually at least one pair even on cheap ones).

Factory radios do not have RCA outputs built in, so a line out converter is needed to convert the high level speaker wire outputs to low level RCA outputs. I will do a how-to on installing these soon.

Some amps have high level inputs. In this case you don’t need a line out converter or RCAs, but if you are using an aftermarket radio, it is still recommended to use RCAs.

Installation

Now that you have everything you need, let’s move on to the installation.

The first thing you’ll need to do is get your layout right. If you are installing a sub, get it in the box and find a place for it. Find a spot for your amp where you can mount it securely and it can get good airflow.

Now you’ll want to disconnect the negative lead on your battery. This will keep you from shorting out any electronics in the car during installation.

Once everything is laid out, you can start running wires. It doesn’t matter what you start with, but I like to get everything run a short distance to a common point where I can run it all back to the amp together with the exception of the RCAs. It is best to run the RCAs down the opposite side of the car to avoid noise.
See this diagram to see what wires go where:

Power Wire
This will be one of the biggest wires in the kit. There will big a long one and a short one. The long one is the power wire. This goes from the +12V connection on the amp straight to the battery.

There should also be a fuse holder and fuse in your amp kit. The fuse should be no more than 18″ from the battery. This keeps the shortest distance possible of wire getting hot in case of a short.

Ground Wire
This will be the short big wire in your kit. The ground wire should be as short as possible, usually 3ft max, and even that is long. This wire will go from the negative terminal on your amp to the vehicle chassis or body.

When making the ground connection, make sure the ring terminal is secured on the end of the wire and find a good spot on the body of the car to scrape off the paint and connect the ground with a grounding bolt or self tapping screws.

It is very important to have a good secure ground connection free of any paint, debris, or rust. A lot of problems are caused by bad ground connections.

Remote Wire
This will be the single long wire in your kit. It is usually blue. It needs to be hooked up to a +12V source that gets power when you turn the key on. This is the wire that tells the amp to turn on when you turn the car on.

For an aftermarket radio: There will be a wire coming off the radio wiring harness (usually blue with a white stripe) that is for remote turn on. Simply connect your remote wire to it and run it back to the amp.

For a factory radio: You will need to find your own source for switch power. Sometimes this can be caught behind the radio, but if not it may be easiest to run it to the fuse box. Either way, fuse the wire!

RCA Signal Cables
These are the cables that carry the low level output signal from the radio to the amp to be amplified. These run from the back of the radio (on aftermarket units) or from your line out converter (on factory units) to the RCA input on the amplifier.

I see a bunch of people hook up their amp with no sound to find out they actually plugged the RCAs into the output on the amp. The output is so you can link two amps together without having to run another set of cables.

Speaker Wire
You are now ready to run your wire to your speakers.

For speakers installed in factory locations (doors, rear deck, etc.) it is usually easiest to run wires behind the radio and cut the speaker wires coming from the doors to the radio and tapping into them there. This is much easier than trying to run wires into each door.

For a sub, you just run the speaker wire straight from the amp to the sub.

Now that everything is hooked up, reconnect the negative lead on the battery and move on to tuning your amp.

Tuning

Once everything is hooked up, you need to tune the amp. There are a few ways to do this: by ear (the easy way), by using a multimeter (the better way), and by using an oscilloscope (the max output way). My old boss swore that it is good enough to set the gain by ear, and it usually was for what we were doing. But I always set gains with a multimeter now.

First you’ll want to roughly set everything:

Filter
Set to low pass for installing subs and high pass when installing other speakers. This prevents low frequency sounds from damaging your mid or high frequency speakers and high frequency sounds from playing through your subs.

Filter Frequency
Usually set around 80-100 Hz depending on personal preference and the speakers used.

Gain
Start with this turned down. This is by how much the incoming signal is amplified which equates to how loud your speakers play. You can’t just turn it up, though, as this can damage your speakers even if it doesn’t sound like it. Setting the gain properly will prevent clipping and overpowering your speakers and increase the life of every component in your system.

Once all of these are set roughly, you’ll need to set the gain.

For this, use test tone frequencies from 0 to -10db. Use about 40-50 Hz for setting your subs and around 1k Hz for setting your mids. Test tones can be found here.

And I’ve also heard use 60 Hz for the subs and 100 Hz for the mids (with the high pass filter turned off). This is because AC voltage meters are made to measure 50-60 Hz tones most accurately. Measuring a signal much higher (like 1k Hz) will result in lower readings, so measuring 100 Hz will be more accurate since it’s closer to 60 Hz than 1k Hz is. But it’s not too low to blow your speakers.

Also make sure all the EQ settings are zero or off (loudness, bass, treble, etc.). Once you get the amps set up and you decide you want to use some sort of loudness or bass boost, I would recommend checking the gains again to make sure they are still playing unclipped.

Easy Way
This really isn’t a recommended way to set amp gains, but it’ll work and be better than nothing.

1. Start with the gain all the way down, and turn your radio up (playing the test frequency) to where it starts to distort and back it down a bit. On most radios this will probably be around 3/4 of the way up. You can go less to ensure your radio isn’t distorting but never turn it up past this level after you set everything.
2. Now start turning the gain up until your speakers/subs start to distort and back off a bit.
3. Done. Now play different sources of music to make sure one or the other isn’t a lot louder (which is usually the case). If so, set it to the source you use most and be careful when playing louder sources.

Better Way
Now to the better way, which is a bit more technical and requires a multimeter.

This way works great if you have an amp that is rated properly, i.e. CEA rated. If you have some cheap amp that says “1500W” and cost $25, that amp probably doesn’t do 1500W and you won’t be able to use this method.

1. Disconnect the positive speaker wires from the amp.
2. Determine gain voltage: V=√PR where V=AC voltage, P=power, and R=resistance. P is going to be the RMS power of your amp in Watts at the impedance of the speakers you are running. R is the resistance of the speaker. And V is the AC voltage we are going to calculate to set the gain. Here’s an example: You have a 4 Ohm 500 Watt RMS sub and an amp that puts out 500W RMS at 4Ω. V=√500×4=44.72V. We are going to set the gain to 44.72V.
3. Start with the gain all the way down, and turn your radio up (playing the test frequency) to where it starts to distort and back it down a bit. On most radios this will probably be around 3/4 of the way up. You can go less to ensure your radio isn’t distorting but never turn it up past this level after you set everything.
4. Set your voltmeter to AC voltage and put the positive lead on the positive speaker terminal that is disconnected from the amp. Put the negative lead on the negative lead of the speaker that is still in the amp.
5. Increase the gain until the meter reads your calculated voltage.
6. Turn the radio down, and turn the car off. Reconnect the positive speaker leads, and you’re done!

To easily calculate the voltage you need, check out the Car Audio Calculator Page.

Max Output Way
This method will get the maximum RMS power out of your amp before it starts to clip.

This way would be best if your subs can handle more power than your amp or if you think your amp may be underrated.

This method uses an o-scope or distortion meter to set the amp gain to the max clean level it can put out.

You can use something like this Pokit meter (I actually got selected for the beta testing and like it but the small size makes it kinda hard to use). The Pokit meter also has a max input of 42 VAC, so it’ll work for most stuff but not super high power amps.

Or an actual oscilloscope like this.

Or a distortion detector like the Steve Mead Designs DD-1. This is very popular in the car audio world and can take an input up to 125 VAC.

This method is similar to using a multimeter, but instead of setting the gain to a certain voltage level, you just set the amp to clip then back off a tad.

1. Disconnect the positive speaker wires from the amp.
2. Start with the gain all the way down, and turn your radio up (playing the test frequency) to where it starts to distort and back it down a bit. On most radios this will probably be around 3/4 of the way up. You can go less to ensure your radio isn’t distorting but never turn it up past this level after you set everything.
3. Hook up the o-scope or DD-1 to the amp channel you are setting.
4. Increase the gain until the DD-1 distortion light turns on or the sine wave on your scope starts to become flat (clipped).
5. Back off on the gain a tad until you have a clean signal.
6. Turn the radio down, and turn the car off. Reconnect the positive speaker leads, and you’re done!

Now that your gains are set, you can fine tune your cutoff frequencies to your liking.

Finishing Up

After all of this is completed, secure the amp and sub down to prevent them from sliding around and yanking wires out. Tire your wires together to make them nice and pretty, and your done! See, it’s not too bad.

This post will explain how to select a subwoofer and/or a bass amp for your setup. I will cover a few different scenarios:

1. You have a sub you want to use but need to find an amp for it.
2. You have an amp you want to use but need to find a sub for it.
3. You don’t have either and are looking to get both a sub and amp.
4. You will be adding speakers and a sub and want to find a single amp to power them all.

1. You have a sub you want to use but need to find an amp for it.

If you already have a sub you want to use or want the same sub as a friend, etc. then you need to find out the specs of the sub. You can usually find these on the box or manufacturers website or a website that sells products (soon to be this one) like Sonic Electronix or Amazon.

What you are looking for in these specs is the RMS (root mean squared, or continuous) power rating, how many voice coils your sub has, and the impedance (ohms). Many subs will have a power rating listed that is max power. This is not what you are looking for when selecting an amp. Your sub and amp will spend most of its time at RMS, not peak power.

Once you find these specs, you need to find an amp with the same (or similar) RMS rating at the impedance your sub is. You can get a more or less powerful amp, but with less power your sub won’t hit as hard. And with more power, you risk overpowering your sub if you don’t tune the amp right (more on that later).

In both of these cases, you run the risk of blowing you sub. If underpowered, you will likely try to turn the gain on the amp up to get the most out of it. This sends a clipped signal to the speaker and can fry the voice coil(s). If overpowered, the speaker tries to play past its max excursion which can break or tear the voice coil, spider, or surround and ruin the sub. Here is a great article explaining this on Crutchfield.

So, it is best to find an amp with a similar RMS rating to your sub. This can be more difficult when going with cheaper brands, though, as they tend to overrate everything. It’s hard to say with these without testing, but if you go with a CEA compliant amp and sub, you know you will be close in ratings.

Here’s an example:

Say you have a 4 ohm single voice coil JL 12W3V3 sub ($240 with free shipping on Amazon) with an RMS power rating of 500 watts. Now JL also has a recommended power range for this sub of 150-500 watts RMS. This means any amp with an RMS rating between 150-500 watts at 4 ohm will work fine with this sub. But we’ll assume you want to get the most out of it, so we’ll look for a CEA compliant amp that puts out 500 watts RMS at 4 ohms.

[amazon asin=B0035VQ5BY&template=add to cart]

Would you look at that! Sonic Electronix has a whole list of CEA Compliant amps. If you are just looking to power a sub, a monoblock amp will be what you are looking for. You can also use a 2 channel amp and bridge the channels, but doing that you can usually only run a 4 ohm sub (which is fine for this situation, but if you add more subs or have a 2 ohm sub may not work – more on this later). So I’m just going to go down the list and find the first 500 watt at 4 ohm CEA compliant amp I see: the Pioneer GM-D9601 ($165 on Amazon with prime shipping).[amazon asin=B00CLFM596&template=add to cart]

Of course if you are set on a different brand or lower price or smaller amp you can sort through and find something else, but that’s it! You’ve found an amp for your sub.

Note: For a dual voice coil sub, the impedance will not be what to look for on the amp. If you have a dual 2 ohm sub, you can either run it at 1 ohm or 4 ohms. If you have a dual 4 ohm sub, you can run it at 2 or 8 ohms. When you add more than one sub, this changes, but there will be more on this later if you are confused.

2. You have an amp you want to use but need to find a sub for it.

This is going to be very similar to scenario number 1, so please read that and I’ll explain the differences here.

So this time you are going to look at the specs on your amp: RMS power at different ohm loads. In the first section you have to match the sub’s impedance with an amp, but in this section you have an amp that can probably handle different impedances. This gives you a little more selection on what sub to get.

If you have a monoblock amp, it may be stable all the way down to 1 ohm (usually 2 ohms, though). If you have a 2 channel amp you plan on bridging, it will probably only be stable down to 4 ohms, though some are stable down to 2 ohms. So find out what ohm sub you want to go with.

Here’s an example:

Assume you have a Kenwood KAC-5001PS ($112 on Amazon with Prime shipping). This amp can put out 500 watts RMS at 2 ohms or 300 watts RMS at 4 ohms. In this case a 2 ohm sub will be louder, so let’s go with that. Now check Sonic Electronic’s (or others’) list of CEA compliant subs. We’ll be looking for a 2 ohm sub rated at 500 watts RMS, or a dual 4 ohm sub rated at 500 watts RMS (see the note above).[amazon asin=B00B8B0Q9A&template=add to cart]

The first one I see on the list is the Alpine SWS-15D4 – 15″ dual 4 ohm sub ($120 on Amazon with free shipping) rated at 500 watts RMS. This can be wired to 2 ohm and get the 500 watts RMS from your amp.[amazon asin=B0081JFX8G&template=add to cart]

There you go. That’s all you need to do to find a sub for your amp.

3. You don’t have either and are looking to get both a sub and amp.

For this one you will simply combine steps 1 and 2 from above, but this can be tricky since there are endless possibilities. You may have a certain budget you are shooting for, or you may have a certain brand you definitely want or don’t want to go with. The best thing to do in this situation is listen to other people’s setups and find one that is right for you and go with a similar setup.

You could also just randomly pick something. Say there is a nice name brand sub or amp on sale, so you get it. Then just go to the section above to find out how to pick the other.

Maybe you think a certain power range sounds good, so you randomly pick 500 watts RMS. Then go find a good 500 watt sub and 500 watt amp.

Once again, there are endless possibilities here, so it is best to read the above sections to get the gist of it.

4. You will be adding speakers and a sub and want to find a single amp to power them all.

For this section, you may already have the speakers and sub you want to use, or maybe just the amp you want to use. In any case, read the above sections to learn how to match power ratings of amps and subs. Matching speakers and amps is coming soon, but is the same  thing as matching single voice coil subs with their respective amps for sake of argument.

To use one amp to power all your speakers and your sub, you can use several different setups:

• 4 channel amp
• 5 channel amp
• 6 channel amp

4 Channel Amp

For this setup, you can either run just your front speakers off the first 2 channels and bridge the rears to power your sub(s) or wire the front and rear speakers on the left together and front and rear speakers on the right together to run on channels 1 and 2 and bridge the rear to power your sub.

Either way, to power a sub and speakers with a 4 channel amp, your sub will be powered by bridging two of the channels on the amp. So in this situation, you will need to find the output ratings for the amp when 2 channels are bridged and match a sub to that or vice versa.

5 Channel Amp

A 5 channel amp will have 4 channels for speakers and a single mono channel specifically for a sub. In this case you will need to match the speaker channels to speakers with the right rating (more on that later but pretty much the same thing as matching subs with amps) and match the sub channel with a sub with the right rating. This is exactly the same as sections 1 and 2 above when matching subs to a monoblock amp. The only difference is you have 4 other channels to power speakers.

6 Channel Amp

This is the same as the 4 channel amp situation, but instead of having 2 speaker channels and 2 of them bridged to your subs, you will have 4 speaker channels and 2 of them bridged to your sub.

Well there you have it. Now you can go find the right sub or amp for your setup. If you still have questions, let me know in the comments or send me an email.

Start at the Source
When you are trying to get the best sound out of your system, you want to start at the source and work your way from there. The best speakers in the world will sound terrible if you are trying to stream Pandora through them.

CDs or lossless music files are the way to go these days, although most head units still don’t support lossless files. I would say the lowest bit rate you should go on mp3s is 320kbps AAC. Most head units will support this format, and iPods support this format. Most head units have great iPod support. Win-win.Also, it will be very hard if not impossible for most normal people to distinguish between this format and lossless. Especially in a car environment (terrible acoustics, road noise, etc).

Head Units

The most popular first upgrade is the radio itself, or head unit. This is for many different reasons: features, looks, customization, better processing, etc. Car companies use cheap parts to keep the cost of their cars down. It’s amazing how much difference a good head unit can make, especially when you can add features your car might not have come with in the process.

Features
Units like this new Pioneer AVIC-8000NEX (discontinued) fit most vehicles with the right parts and greatly improves the looks and functionality of your dash. DVD playback, smartphone compatibility, navigation, are all features you can have when adding an aftermarket head unit.

You can see how this is a popular first upgrade for your sound system. You can even add external monitors and sources such as headrest TVs or a backup camera. Adding an aftermarket radio also makes it easier to add external amplifiers.

Sound Quality
Not only do aftermarket radios offer better features, they usually offer better sound quality, too. Most stock head units have cheap DACs (digital to analog converters). When you upgrade your head unit, most of the time you are upgrading the DAC as well. Units like the Pioneer DEH-80PRS ($324 on Amazon with Prime shipping) offer three separate Burr-Brown DACS and 3 volt RCA outputs for the ultimate in sound quality.

Louder Sound
Aftermarket units also offer more power than stock head units (not stock amplified systems, though). Most factory radios have around 5-10 watts RMS per channel on their built in amplifiers. Most aftermarket radios offer around 15-18 watts RMS per channel (although they advertise 50W; this is a max power rating, though).

Subwoofers/Amplifiers

Subs are probably the next most popular upgrade whether it be for sound quality or SPL (sound pressure level, aka loud).

Sound Quality
Subwoofers are not just to make loud boomy noises. They also greatly increase the sound quality in a few different ways.

One way they help with sound quality is they introduce low frequency sounds that most factory speakers or even aftermarket mid range drivers can’t reproduce clearly. This lets you hear low sounds that you couldn’t hear before that add depth and richness to your music.

Another way they help with SQ is take bass out of your mid range speakers. Most factory systems have full range speakers. This means the signal going to them consists of the very low frequencies and the very high frequencies that these speakers can’t produce. This makes them sound distorted when you try to play bass through them.

When you add a sub, you can set it to play the low frequencies only and set your other speakers to play only the frequencies higher than that. This allows each speaker to be within its sound reproduction range and makes everything much less distorted.

Sound Pressure Level
Another popular use of subwoofers is to be loud. This is usually for people trying to show off or compete in SPL competitions. In these setups you usually have the biggest or most subs you can fit/afford with a lot of power going to them. These are the systems that go bump and wake your neighbors late at night.

Amplifiers
In order to add a sub, you have to have an amp to power it. Since head units usually only put out 50W max, you need to add a more powerful external amp to put out the higher power levels subs need since they are a much bigger driver than your typical 6.5″ speaker. Subs usually require at least 150W RMS to perform (depending on the driver).

Some people want to add a little bit of bass in a small package. Sub and amp combos like this Infinity Basslink ($230 on Amazon with Prime shipping) powered subwoofer have the amp built in and take up less room without sacrificing too much bass performance

Speakers/Amplifiers

The next upgrade step is usually the speakers, specifically the front. This can be done with or without adding another amp, but you will get much better performance in terms of quality and loudness with one. The front speakers come first because that is where the sound is being projected towards you, and setting up a good front stage can make it sound like a concert in your car. Rear speakers are usually just used for fill or not used at all when quality is your concern. For loudness, you’ll add all the speakers you can.

Coaxial Speakers
Coax speakers are the ones with the tweeter built into the center of the speaker like these Polk Audio db651‘s ($65 on Amazon with Prime shipping). This design allows for more simple installation than component speakers but still adds much better quality than factory speakers. These are a very popular choice due to being more inexpensive and easier/cheaper to install than component setups.

The tweeters are usually crossed over with the use of a capacitor which gives it a -6dB/octave slope at a fixed crossover point to block low frequencies from playing through, and damaging, the tweeter.

Component Speakers
Component speakers, or separates, are speaker setups that separate the tweeter from the mid range driver so the tweeter can be located to better improve sound quality. Since higher frequency sounds are easier to localize than low frequency sounds (h

ence why the sub is all the way in the trunk usually, the speakers are way down in the door panels, and the tweeters are up high), placing the tweeters closer to ear level and facing them at the driver raises the sound stage and greatly improves the sound quality.

Components usually come with an external crossover with a more advanced network than a single capacitor. These usually have a second or third order crossover set at a certain frequency offering steeper crossover slopes and usually consist of an L pad to dim the tweeters down a few dB to make them not as harsh.

Amplification
Speakers can be amplified with the head unit, but adding an external amp greatly increases output and sound quality. This is especially true when running components since the passive crossovers aren’t too  efficient and require the recommended RMS power to sound best.

Basically, if you can afford it, do it.

These are the basics of sound system upgrades. Depending on your budget you can do one or all of them to improve your sound.