Best Car Audio Capacitor 2023

Not many people know that a capacitor is an essential part of any quality audio car system. A capacitor is a device that is designed to store and discharge electric energy. Unlike batteries, they release their stored energy rapidly and fill up just as quickly. This makes them ideal buffers for systems that occasionally need more electric energy than they have available. The car audio systems are one of those.

Car audio capacitors also called stiffening caps, are used to smooth out power surges in a car’s electric system when an amplifier suddenly draws a lot of it. When that happens, all other systems experience a shortage in supply, which may result in some unpleasant situations, like the entire dashboard dimming out. During the night, this can cause some safety issues, as the driver struggles to see the speedometer or any other gauge on the instrument dash.

Capacitors prevent this by quickly releasing their stored power and equally quickly recharging, awaiting the next spike in consumption. Simply put, the car’s alternator can’t produce enough juice to run every electrical component in your vehicle and a capacitor acts like a reservoir that allows the amplifier to get as much power as it needs in a very short amount of time.

Powerful audio amplifiers can often draw more power than the car system has available due to high volume and massive power output. The common misconception is that the car audio capacitor will improve the quality of the sound, which simply isn’t true, as the capacitor doesn’t have anything to do with sound. It will, however, provide a steady power supply to your system, allowing it to run at peak efficiency at all times.

Under-voltage may cause your amplifier’s performance to decline, so while a capacitor doesn’t improve the sound quality, it prevents its deterioration. Even if your dash doesn’t suffer any negative consequences, it is advisable to install it, for that exact reason. This is especially true if you like your music to have a nice dose of bass. Once the thumping begins in earnest, the amplifier works in overdrive, drawing massive amounts of electric power.


To ensure that there is enough power in the system, you should consider installing a capacitor. Not only will it ensure everything runs properly, but it will also prevent straining your alternator, causing long-term damage.

Choosing the right size capacitor is rather straightforward. A rule of the thumb is that you should get 1 Farad of capacitance for every 1,000 watts of the total power of your system. For this calculation, you can safely use RMS numbers as your guide. Of course, this is the minimum size of a capacitor. While getting a smaller one will not yield the results you want.

There is nothing wrong with getting a bigger one. People often get 2 or even 3 Farads per 1 kW of RMS. This can only improve the performance of the whole system and can’t hurt if you can afford it. The capacitor should be installed as close as possible to the amp. The shorter the wire connecting the two, the faster the reaction time will be.

Choosing the exact type and model of a car audio capacitor is an entire issue altogether. They have become very popular with car enthusiasts and one of the most sought-after electric components. As a result, there are so many models on the market that it is hard to choose one, especially if you aren’t all that familiar with ins and outs of electricity.

This article is our effort in making it easier for you to find a car audio capacitor that is just right for you.

We have found a great list of car audio capacitors on the CarInMyDNA site. Visit their website for a more detailed look at every model.



One of the smallest models on the market, PYLE PLCAPE50 won’t be suitable for powerful systems, but for your everyday needs, it will work just fine. It has a capacity of five Farads and a handy LED display. Installation is easy, as the capacitor comes with two mounting brackets. It can be used in vehicles with either 12 V or 24 V batteries.

Rockville RXC4D 4 Farad Digital Car Capacitor


Rockville has made an excellent capacitor that comes in various sizes. You can get this model in 2, 4, or 20 Farads, depending on your needs. While we would like to see at least one more size between 4 and 20 Farads, these three will still cover a lot of models. It is a relatively cheap unit, making it a budget option. It is fully enclosed and protected against dust. However, some users have reported charging issues, which is worrisome. Also, we couldn’t find any data on the warranty.

Planet Audio PC10F


Planet Audio PC10F is probably the best option on our list. It comes in 2, 10, 20 Farads capacity. The 10 Farads model is in the sweet spot and will be suitable for most people. It is relatively affordable, offers a competitive choice of sizes, and is quality made. Some people did complain about noise interference when using it, but that may be an individual issue, originating from some specific combination of devices they use.

Rockford RFC10HB


With RFC10HB, Rockford now has a complete offer of car audio components. The unit is lightweight, small, and stylishly designed, making placement an easy affair. You don’t even have to hide it under a dash. It comes with excellent surge protection, protecting your amplifier from sudden power changes. The downside is that it is quite expensive, costing by far more than any other capacitor on our list. RFC10HB has only basic functions, lacking any special features of other units on the market.

BOSS Audio CAP8 

Designed with high-powered amplifiers on mind, BOSS Audio CAP8 has a capacity of 8 farads. It has many features, including auto-sleep, alert, a sturdy metal casing, and an LED display. The alert tone will notify you in case any malfunction happens, which can be handy.