Audio capacitors make sure that your music listening experience remains consistently smooth while preventing your car’s amplifier and battery from over-straining.
If you’re an audiophile like me, this is a car component that you probably should be paying attention to.
Earlier this year, I had someone come up to me, asking for advice on which capacitor to buy for their pickup truck.
As always, I like to do my research before I make a product recommendation. So I got my hands on ten highly-rated audio capacitors models and got to testing. I managed to pick out my four best car audio capacitors, which you can read about below.
- The Best Overall Car Audio Capacitor
- Car Audio Capacitors 101
- Our Top Four Picks
- Frequently Asked Questions
The Best Overall Car Audio Capacitor
If I had to go with one capacitor out of these four for at least a couple of more years which one would I choose? It’s a tough one to answer, considering that each of these units seems right for me in some ways and not so much in others.
However, after a lot of thinking, I finally chose the Planet Audio PC10F as my overall favorite.
To begin with, it has the highest capacitance rating out of all the units on this list.
Having 10 Farads at my disposal is quite handy because, in addition to an amplifier, I also have an equalizer and a head unit installed inside my car. Hence, I need the extra power.
10 Farads means that I could also upgrade to a more powerful amplifier in the future.
Another reason for choosing the Planet Audio PC10F is the audible alerts. When it comes to car maintenance, I’m the kind of person that likes to stay on top of things so these alerts could serve me well.
In the case of an overpowering voltage surge, I could immediately switch off my stereo and start diagnosing the problem.
Car Audio Capacitors 101
What Exactly Are They?
Did you know that when you play music through your car stereo, particular notes or entire sections can draw an immense amount of power from the amplifier?
This is very common with loud bass and drum notes and they can suck in so much power from your car’s battery that it’ll cause your headlights to grow dim for that duration!
Plus, if your battery isn’t able to supply the amount of current needed, then the notes simply won’t sound right.
When amplifiers try to pull a lot of power directly from the battery, it can lead to a significant drop in the voltage.
The size of the drop can vary depending on how much power is required by the amplifier and how much resistance the wire leading from the battery to the amplifier carries.
Car audio capacitors exist to help power issues like this. To put it very simply, audio capacitors are secondary reserves that can store large quantities of electrical power.
Hence, when demanding car components like amplifiers need a ton of power, they can draw from this reserve without straining the car’s battery.
Unlike car batteries, capacitors have rather minimal internal resistance. As a result, they can supply a huge burst of current much faster than a regular battery.
But what if there are a lot of power-hungry bass and drum notes in your music? Fortunately, car audio capacitors are as quick to charge as they are to discharge. This means that they can keep dispensing a large amount of power whenever required.
Do You Really Need A Car Audio Capacitor?
Not everyone is going to need a car audio capacitor, especially if you hardly listen to music through your car stereo.
However, if you’re dealing with one of the following, then I do recommend that you look into one:
Having a very powerful amplifier – if you know that your amplifier is going to be particularly power-hungry then you should probably get an audio capacitor as a precaution.
Having a weak alternator – the alternator is the engine part that’s responsible for charging the battery and the general running of the electrical systems of your car as a whole.
The alternator distributes power to different car components. Hence, when an amplifier draws a disproportionately large amount of power, the alternator will try to compensate by limiting the quantities of current sent to other parts.
When this happens you’ll notice things like your headlights flickering or the bass response from your subwoofer growing weaker.
Having a battery with low-capacity – if your battery isn’t able to dish out the amount of power needed then it’s probably best to get a capacitor instead of straining it continuously.
Having a very long or thin amplifier wire – the longer a wire is, the less efficiently it’s going to transfer current. Likewise, if a wire is thin, its resistance is going to be relatively high.
In both cases, having that extra ‘push’ from a fast discharging capacitor can help make sure that the amplifier receives enough power.
What Do You Need To Consider Before Buying An Audio Capacitor?
There are a few important factors you need to pay attention to if you want to buy a capacitor that’ll perfectly fit your car’s setup.
The capacitance value rating, measured in Farads, tells how much charge the capacitor is able to store. The higher the rating, the more current the capacitor is able to discharge.
The capacitance rating will indicate whether or not a particular capacitor is compatible with your existing car amplifier.
For instance, if the amplifier’s power rating is at 2,000 watts, then a capacitor with a capacitance rating of 2 Farads should go along well with it.
The more powerful the amplifier, the greater the capacitance value needs to be. This correlation was determined experimentally in the late 1980s and has been the accepted rule ever since.
One part of this rule that is often overlooked is the fact that regardless of the power rating of the amplifier, the capacitance value should be a minimum of one capacitance.
The Number of Terminals
The more terminals the capacitor contains, the more equipment that it’s able to power up.
Hence, if you’re also using devices like FM transmitters and equalizers with your car stereo, then a capacitor with multiple terminals is probably better for you.
The Type of Capacitor
There are mainly two distinct types of capacitors: electrolytic and carbon. Electrolytic capacitors are generally faster when discharging while the carbon ones are able to hoard more power in their storage.
These days, you can actually find electrolytic-carbon hybrids that offer the characteristics of both.
Voltage Overload Protection
Every Capacitor has a maximum capacity when it comes to the level of voltage they can handle.
Typically, this is indicated by its surge voltage (the working voltage tells you how much power it can handle on a continuous basis).
Exceeding this level can cause irreparable damage to its components. Hence, I always recommend buying a capacitor with voltage overload protection like automatic shutoff.
This will ensure that the capacitor lasts the entire duration of the advertised lifespan.
I’m constantly busy so I don’t have the time to manually check the charge level on my capacitor. Thankfully, a lot of capacitors these days give you audible alerts whenever something is wrong.
For instance, if the voltage drops or there’s too much of a surge, then an audible alert is quite handy because you can immediately apply a quick fix like turning down your car stereo.
Ideally, your capacitor should take less than a minute to charge.
Not only does this allow you to have a smoother, more consistent listening experience, but it’ll also prevent the capacitor from overheating as well.
Our Top Four Picks
Now that you know what car audio capacitors are, how to tell if you need one and which factors to keep in mind when purchasing one, let’s look at my top 4 picks for this year.
As you go through the reviews, pay attention to the technical specifications so that you can determine whether these capacitors are compatible with your own setup.
Planet Audio Pc10f
- 3 Digit Bright Blue Digital LED Voltage Display, Blue Illuminated...
- Audible Warning Tone for Reverse Polarity, Voltage Overload and Low...
- Voltage Measurement Accurate to + / - 0.1 VDC
- Capacitance: 10,000,000, Working Voltage: 16 VDC, Surge Voltage: 24...
- Equivalent Series Resistance: 0.015 Ohm @ 100 Hz / 25°C, Capacitance...
The Planet Audio PC10F sports an illuminated LED display that shows you the current-voltage of the capacitor.
Hence, you don’t have to buy a separate voltmeter or take your car to a mechanic in order to find out whether the capacitor is running low. Plus it looks really cool in my opinion.
The PC10F will alert you when there’s too much of a voltage surge, low voltage or reverse polarity (occurs when the capacitor has been installed incorrectly, causing the positive terminal to turn negative and the negative terminal to positive).
This enables you to take quick action instead of straining the capacitor further.
The PC10F has a capacitance rating of 10 Farads, which means that you can connect really powerful amplifiers without having to worry about your headlights dimming or the sound output being weak when those really demanding notes hit.
High Surge and Working Voltage
The PC10F has working and surge voltages of 16V and 24V (direct current) which seems enough to protect it from over-voltage on a consistent basis.
- LED Display indicates voltage level at all times
- High working and surge voltage
- Sleek aesthetic that can blend in with most car interiors
- Compatible with very powerful amplifiers
- Audible alerts
- A bit slow to charge compared to most capacitors I’ve tried. However, it still takes less than a minute.
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Rockville RXC4D sports two LED displays: one in blue and the other in red. The red light gives you the current-voltage reading so that you can check whether there’s an over-voltage or low voltage.
In contrast, the blue light indicates charge and discharge metering, allowing you to keep track of how much power is present in the reserve and how much is supplied to the amplifier.
High Capacitance Value
Rockville RXC4D has a capacitance value rating of 4 Farad which is less than what you get with the Planet Audio PC10F but still more than enough to work with a decently-powerful amplifier.
Remember, for every 1000 watts, you’re going to need 1 Farad.
Working and Surge Voltages
The Rockville RXC4D features a working voltage of 12 Volts and a surge capacity of 24 volts which meant that I didn’t have to worry about over-voltage as much.
Built-In Protection For Reverse Polarity
Reverse-polarity can have very harmful effects on the capacitor and potentially on you. When the polarity of the terminals is reversed, an exceedingly large current can flow, leading to severe overheating of the unit.
In certain cases, this generated heat can actually lead to an explosion.
Fortunately, the Rockville RXC4D prevents this from happening with its IC controlled circuitry which protects against reverse-polarity.
- Compatible with high-powered amplifiers
- Displays voltage and charge/discharge readings
- High surge voltage protects against over-voltage
- Built-in protection for reverse polarity
- Remote control included
- Does not come with audible alerts
- SUPPORTS CAR AUDIO SYSTEM: A high-demand audio setup can often place...
- BLUE DIGITAL DISPLAY: It's got all you need to make sure your system...
- SAFETY FEATURES: Equipped w/ electronic polarity protection circuit...
- MOUNTING HARDWARE: The digital power capacitor includes mounting...
- 5.0 Farad Digital Display Power Capacitor - Chrome Plated Post Kits -...
LED Voltage Display
Like most of the capacitors on this list, the PYLE PLCAPE50 features a blue LED display which indicates the voltage at which the unit is operating.
Considering that the PLCAPE50 does not audibly alert you to extreme voltage fluctuations, this feature is very handy when trying to prevent over-voltage or low voltage.
With a capacitance value rating of 5 Farads, this capacitor is quite capable of working with powerful amplifiers.
I could crank up my stereo and not have any problems with the intensity of the car headlights or the bass response coming from my woofers.
Working Volume And Surge Capacity
The working and surge volumes of the PYLE PLCAPE50 are 12V and 24V respectively.
These values mean that the capacitor can handle a decent amount of voltage surging without having its internals fried.
Brushed Aluminum Case
The brushed aluminum exterior of the PYLE PLCAPE50 gives it a very sleek look but it probably won’t blend in all that well with most car interiors.
- LED display helps to keep track of voltage level
- Compatible with high powered amplifiers
- Can withstand voltage surging.
- May not blend in well with the aesthetic of your car’s interior.
Planet Audio Pcblk2.0
- 3 Digit Bright Red Digital LED Voltage Display
- Audible Warning Tone for Reverse Polarity, Voltage Overload and Low...
- Capacitance: 2,000,000, Capacitance Tolerance: + / - 10%, Voltage...
- Working Voltage: 20 VDC, Equivalent Series Resistance: <0.00195 mW @...
- Dimensions: 3 x 3 x 10.3, Unit Weight: 3.5 Lbs
Audible Alert Tones
The Planet Audio PCBLK2.0 features warning tones for reverse polarity, over-voltage and low voltage issues occurring inside the capacitor.
This meant that I didn’t have to take my car to a mechanic to find out whether they were any performance issues. When it comes to reverse-polarity especially, it’s absolutely necessary to take fast action.
Despite having alert tones, the PCBLK2.0 also features a bright red LED voltage display so that you can keep a check on the voltage levels at all times.
This allowed me to keep an eye out for any symptoms that indicated a problem was developing.
The Planet Audio PCBLK2.0 has a capacitance value rating of 2 Farad which isn’t all that high compared to most of the other capacitors on this list.
However, this unit can still work with medium-powered amplifiers.
High Working and Surge Voltage
The Planet Audio PCBLK2.0 has the highest working voltage on this list, with a rating of 20V.
This means that it can handle lots of power flowing through it on a daily basis.
Its surge voltage is rated at 24V which puts it in the same league as the Planet Audio PC10F.
- Warning tones will alert you immediately on polarity and voltage issues
- LED voltage reading lets you keep track of the operating voltage at all times
- High working voltage and surge capacity protects the unit from over-voltage
- Capacitance value rating is comparatively low
Frequently Asked Questions
This FAQ section covers the most common questions I get asked about car audio capacitors:
Which Is Better, A Capacitor Or A Battery?
People often wonder whether it’s best to get a second battery to power their stereo or a capacitor. Either choice offers different benefits.
To begin with, a second battery can be less expensive to purchase and install than a capacitor. In addition, batteries can provide the same amount of electrical storage while taking up less space inside the car.
On the other hand, capacitors are much quicker to charge and discharge which is ideal if you listen to a lot of music in the car. They are also less susceptible to voltage drops.
Can A Car Audio Capacitor Go Bad?
As long as the capacitor doesn’t suffer major issues like over-voltage or reverse-polarity, then it should generally last a long time.
Unlike flood batteries, capacitors don’t leak. However, they can occasionally swell if too much voltage is supplied to them.
How Do You Hook Up A Car Audio Capacitor?
There are a number of steps to follow when installing a car audio capacitor. First of all, you need to make sure that the capacitor has been completely discharged.
The voltage display should help you confirm this. Similarly, you should disconnect the battery ground terminal so that you can work safely.
Mount the capacitor in an appropriate place inside the car. Ideally, it should be close to your amplifier.
Following that, connect the capacitor’s positive and negative terminals to the positive terminal of the battery and the ground respectively.
Afterward, connect the remote turn-on wire to any 12V power source in the car, such as the cigarette lighter, amplifier or ignition switch. The remote turn-on wire helps kill power to the capacitor when the car is turned off.
Finally, reconnect the battery ground terminal.
How Long Does It Take To Charge A Capacitor?
This depends on the internal resistance of the capacitor and its capacitance value rating. The mathematical formula for calculating charging time in seconds is 5RC, where ‘R’ is resistance and ‘C’ is capacitance.
So for example, if we take a capacity that has a resistance of 3 ohms and capacitance of 1 Farad, the charging time will be 15 seconds.
What Happens If You Don’t Charge A Capacitor?
You simply won’t be able to extract any power from it. After hooking up the capacitor, you need to take a resistor and connect it to the terminals present in the amplifier’s in-line fuse holder.
In 10 to 30 minutes, your capacitor will receive its initial full charge.
The products featured on this page were last updated on 2023-05-28 at 16:39 /. Affiliate links / Images from Amazon Product Advertising API.