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What Is an Epicenter for Car Audio?

If you are a car driver who likes to have the best sound system possible, especially with solid and natural bass, you may need to check out the Epicenter.

But what is an epicenter in the car audio, and how it works? Let’s find out below.

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Generally, the Epicenter detects bass harmonics and digitally recreates the low frequencies, delivering live music’s incredible punch and impact. The Epicenter is the key element of many professional sound systems, allowing a stronger and louder bass.

As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.

Tip: Depending on the car type you have, you may need to install INDASH Epicenter, which allows you to take complete control of the bass directly from the front seat without leaving the driver seat and opening the trunk. 

In the article below, I will go deeper into the functionality of the Epicenter and will explain installation methods.

What Is the Purpose of an Epicenter in Car Audio?

The main reason epicenters are being installed in the car audio systems is the reproduction of the lowest tones removed during the music production process.

As you know, the low tones add dynamic to the music changing completely the audio experience.

A standard car audio system with only a car radio and speakers cannot reproduce a full depth sound.

With a car audio epicenter installed in the car audio system and with the help of an additional car amplifier, you will be able to play deep tones from your subwoofer you did not know existed.

Audio Control Epicenter vs. Soundstream. Which One Is Better?

Epicenters from Audio Control and the Soundstream are most commonly installed in car audio systems, but are they the same?

They work in the same way and are similar, but…

Soundstream is more budget-friendly, so its components have lower quality and cheaper materials than AudioControl.

AudioControl is all about quality, and this company is really good at it. All new products have a five-year factory warranty, and that should say it all. Also, the design of the Audio Control Epicenter is less fancy and more professional than the Soundstream.

AudioControl The Epicenter Bass Booster Expander & Bass Restoration Processor with Remote (Black)

When it comes to the products, AudioControl offers two but completely different models:

  • The Epicenter – installed in the trunk or close to the amplifier
  • The Epicenter INDASH – installed in the dash area

Although Soundstream has several different models in the offer, it is actually identical Epicenter unit inside, but in different colored boxes, which may look nice, but do not sound any better than AudioControl.

Soundstream Bx10x Bass Reconstruction Processor -Black

The main difference between the AudioControl and the Soundstream is the price, which is the only plus of the Soundstream.

If you do not mind spending more on the best quality product, go for AudioControl.

Otherwise, if you are on the budget and still want to have better bass from the subwoofer, the right choice would be the Soundstream.

How Do You Tune an Amp and Epicenter?

Epicenters are equipped with two base controls, the “sweep” and the “width.”

Adjusting these controls allows you to optimize performance to the vehicle type, size, and individual needs based on the music type.

The “sweep” control allows you to choose the center frequency, which varies from 27 Hertz to 63 Hertz, and it should match the peak frequency for your subwoofer.

When you choose the frequencies close to the top end, the bass will become shorter, and you will feel more of a punch than just longer but softer vibrations.

On the other hand, the “width” allows you to control the shape of the filter around the centered sweep frequency.

In other words, it makes boosted frequencies broader or narrower around the central point selected by “sweep.”

Remember that both settings will be different for the different types of music you listen to. For example, for a rock, you will hear a lot of extra basses, especially for short drums kicks.

Therefore, you’ll likely need to select higher “sweep,” lower “width,” and longer decay than for electronic music where the bass is not so wide.

Settings are also different for sealed subwoofers versus bandpass or ported enclosures because of the various bass types they produce.

How Do You Set the Control Epicenter?

Setting the Epicenter is not complicated, but there are a few rules you have to remember about if you want to achieve the best results and how strong you want the bass to become.

To do it right, there are two bass controls outside the box, and they control the Para-Bass functions of The Epicenter, which I already mentioned earlier.

  • The “Sweep” knob allows you to pick the center frequency that you want The Epicenter bass restoration circuit to maximize, and this should match the peak frequency subwoofer enclosure was designed for. The adjustable frequency range is between 27 and 63 Hz.
  • The “Width” control then allows you to control the shape of the filter centered around the “sweep” frequency.

That is is when it comes to the outside control, there is more inside the Epicenter:

Input Grounding

For most systems, you can leave this set in the balanced position, but it can sometimes happen that the car radio may “search” for the ground through the RCA connectors.

In this case, you should change it to the unbalanced position, but again this is rare, and you may not experience it at all in your car audio system.

Ground Isolation

Ground Isolation makes alternative grounding connections, and it reduces the whine effect that may occur when the source unit and amplifier use different grounding.

Before adjusting to the ground isolation settings, remember to double-check that the audio system is turned off.

Bass Output Control

Because not all systems are designed the same, there may be differences between the SPL (sound pressure level) in various subwoofers.

Bass Output Control can either increase or decrease the signal voltage of the bass restoration circuit to make the sounds of the best quality.

The Epicenter’s factory-recommended settings are based on the subwoofer’s size:

  • 8″ – 2.5V
  • 10″ – 5V
  • 12″ – 7.5V
  • 15″ and more – 10V

PFM Subsonic Filter

This filter has been designed to protect the speakers from playing too low frequencies that could cause their damage.

The filter is fully programmable, and it allows you to adjust the PFM roll-off frequency to whatever you choose.

The factory-installed module at 33Hz will work with most subwoofers, but in case of any smellers that do not support the 33Hz, you may need to raise this value to approx. 3dB higher than the bottom frequency of the specific subwoofer.

To change the PFM frequency, you need to remove the top of the chassis and change the modules inside the device.

Can I Use Epicenter in the Car Without a Knob?

Standard knobs used in amplifiers are not needed for correct amplifier functioning, and they are often a nice to have rather than the required device.

However, when it comes to the Epicenter, it will not function without a knob as expected, and when the knob is not connected, the system puts the Epicenter into a bypass mode as a default.

In other words, if you do not have the Epicenter knob connected, the Epicenter effect is off, and when looking at the lighting at its top cover, it will be turned off.

The Epicenter remote knob controls the effect added to the existing signal and is needed for correct functioning.

The more you turn it up, the more bass frequencies are added to your audio signal, and if you turn it all way down, it adds almost no additional bass frequencies to the audio signal.

How Do You Set a Wide and Sweep Epicenter?

You may want to set a wide epicenter so that you can achieve more coverage in the car.

To do this, you first select your primary center frequency by adjusting the “sweep” control at 27 Hertz, then turn the “width” to the middle.

The car subwoofer manufacturer will recommend their own car subwoofer setting configurations for each car audio system. This is because every car audio engine differs, as well as music listening genres.

For example, an epicenter used with hip-hop music should be set to a different frequency than when associated with rock or jazz.

First, you have to set the “sweep” to match the peak frequency for the subwoofer.

After that, set the “width” to increase the car subwoofer’s performance and adjust for the best audible effect. In most cases, it will be in the middle or slightly below, but it depends on the subwoofer’s construction and the music type.

How Do You Activate the Epicenter?

Activating the Epicenter is as easy as turning on the car stereo. When the car’s ignition is turned on, a power supply for all car electronics is activated and starts feeding voltage to car audio components.

However, many make a mistake during connection and ignore the importance of the remote wire.

The remote wire from the Epicenter has to be connected with the remote wire from the car stereo, which is the first step.

When your Epicenter’s power, ground, and remote wiring is correct, ensure that the RCA signal wires are connected from the stereo.

After turning the radio on, you should see the lights on the Epicenter, which means it has been activated and receives the audio signals.


Epicenter is a small device that reproduces the lower tones to their original level and is especially needed for the older tracks.

Installation is straightforward, and the Epicenter has to be connected right after the signal source, which is in most cases the car stereo, but definitely before any crossover or equalizer.

Epicenter works the best when it receives most of the original signal and sends it for further amplification.

If you want to give it a try, this tiny device from AudioControl will put your music experience in the car to a different level.