What are factory sound processors?

Upgrade your sound and keep your factory stereo


Zak Billmeier

Zak Billmeier grew up in southern Vermont and coastal Maine. After graduating from Mary Washington College with a Geography degree he still isn't sure quite what to do with, he eventually settled in the mountains of Central Virginia. He spends his free time chasing his daughter around, taking pictures, gardening and cooking. He joined Crutchfield's car A/V writing team in 2007 and is now a lead producer on our video team.

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Factory car stereos are getting more and more complicated, as car manufacturers move away from standard-sized receivers to complicated, integrated designs. Often they are tied into a navigation system, climate controls, or other electronic functions, which make swapping them out for aftermarket stereos difficult or even impossible. The problem is, its sound might not be up to your lofty standards.

Replacing the factory speakers is a great way to start. You might also choose to add an amplifier or subwoofer — or both. All of these things, done together or on their own, will improve your factory stereo's sound. But there will always be something holding you back, and it's built right into the stereo.

Factory stereos have built-in sound shaping

Your factory stereo uses preset equalization designed to make cheap factory speakers sound better, meaning that it automatically adjusts the different frequencies, creating audio "peaks and valleys" which can degrade sound quality. It is particularly noticeable when you add amplifiers, speakers and subwoofers to your setup, as any deficits in the sound are literally amplified.

Most factory stereos also limit the bass output as volume increases in an attempt to protect the speakers. The trouble is, even if you upgrade your speakers and install an amp and subwoofer, the bass output is still limited by your factory stereo. This throws your system out of balance and makes the bass sound muddy and weak.

So what if the factory sound doesn't cut it?

Fortunately, there's an easy cure. You can install a sound processor, which strips away the sound-shaping limitations enforced by your factory stereo and sends a clean signal to your external amplifiers. The amps send the signal to your speakers and subs. Your reward will be resonant lows, sparkling highs, and a realistic sense of space and depth.

Are these sound processors complicated to install?

Installation generally isn't too difficult — these processors connect to your stereo using your vehicle's speaker wires, and then to your amps and subs. You'll be able to keep the look and controls of your factory stereo, but expand your system for serious sound.

Sound processor setup
  • A sound processor connects to your factory system through your stereo's speaker wires.
  • The processor removes the factory sound-shaping, so the signal is clean.
  • The signal is sent to your external amplifier(s). The amps power your front and rear speakers, and subwoofers.

We carry several different factory sound processors, each with slightly different capabilities. Here are a few:

Audio Control LC6i

AudioControl's line of factory sound processors lets you take your factory stereo to a new level — they can convert the amplified signal from premium factory systems so you can add your own amps and subs. Their line drivers can send a clean, 9.5-volt signal to an aftermarket amp, giving you clean sound. All their processors have highly customizable configurations.

Alpine PXA-H800

Alpine PXA-H800: Alpine's IMPRINT™ sound-shaping technology is the secret to this processor. Place the included microphone wherever you want and IMPRINT measures your vehicle's acoustics and uses its powerful digital processing to clean up the factory sound and tuning the stereo's output specifically to match your vehicle. You'll be able to tweak the sound a lot further with over 31 bands of EQ per speaker channel and over 10 bands for the sub.

Rockford Fosgate 3Sixty.3

Rockford Fosgate's 3Sixty.3 processor works with your laptop to give you awesome control. Once you load the software from the included setup CD, you can connect the 3Sixty.3 to your laptop with the included USB cable, and get to work creating a perfect-sounding system with the user interface controls displayed on your computer's screen.


The Helix DSP PRO processor works with your PC to open up a world of sonic adjustments that will maximize the performance of almost any car audio system. The DSP PRO processes its digital signals at 64-bit resolution and 96 KHz sampling rate so you'll get very high fidelity sound along with virtually no noise or distortion.


The Helix DSP PRO's display shows all the controls and settings on your computer screen

Give us a call to see which of these factory sound processors is a good match for your needs. One thing's for sure, your factory stereo will sound a whole lot better.

  • Mr Innovator from Oregon

    Posted on 6/16/2015 3:51:19 PM

    Highly considering an Aftermarket HU for my 2014 Toyota Tundra however my door lock,chimes etc maintenance, Navigation & personal reminders are all integrated into factory HU. Crutchfeild has several aftermarket HU choices BUT the dilemma is if I go that route how much of the those so called minor conveniences from the factory am I willing to lose, for example on my model if I forget to close the sunroof and exit the vehicle I get an immediate chime to remind me that it's left open. A minor loss if it can't be integrated into a aftermarket HU, but it's a major loss if it happens to rain & you forgot because of the former factory reminder. I think Crutchfeild will eventually do this but they or someone should do a item by item cost benefit analysis of retaining factory HU vrs aftermarket HU, not your run of the mill audio specs. As any respectable audiophile knows the factory DSP's is so choked down & unalterable that it's almost worthless to modify with add on's. I assume a aftermarket FSP would solve most of these issues but a real hard core test would be how much of a sound stage do you get vrs dumping the entire manufacturers system & getting a proven aftermarket HU with programable sound stage. I'd Like to hear from any Tundra owners that have done ONLY an FSP add on to factory & someone that went 100% aftermarket then have both list pro's & cons of their install & soundstage.

  • Robert Ferency-Viars from Crutchfield

    Posted on 6/17/2015 1:23:06 PM

    I think your situation is pretty cut and dried, as far as the cost-benefit goes: if you change the stereo, you lose the navigation system, aux & USB inputs, and you have to hardwire all the connections. In my mind, that's not worth doing in a nice truck that has a pretty good factory stereo system. Maybe put in some aftermarket speakers (but make sure you get low-impedance speakers to match the factory speakers) or a subwoofer. Of course, using a factory signal processor changes that. You get to keep all the nice bells & whistles Toyota gave you in the dash, but replace all the other audio components with your choice of amps and speakers. Your truck is a prime candidate for this approach. Give us a call if you have any questions or would like some help selecting the gear.

  • Pavol from Prague

    Posted on 6/24/2015 6:45:49 PM

    Hi there, Considering to upgrade speakers on my VW Golf Mk7 with 2-way FOCAL Performance Expert PS 165F (both in front and rear doors). In addition the doors will be filled with three layers of noise blocking and anti vibration material (ZN FINISH and STP GOLD). I am concerned with the output of the stock Composition Media stereo (4x20w). Could you please give me an advice if the stereo's output will be appropriate in comparison with the speakers' output? Shall I rather go for lower Focal series as the factory stereo will not be able to utilize full 165F's potential? Or shall I rather buy aftermarket DSP/amp in order to match the speakers' level? My goal is just to have crispier sound at normal level of sound volume hence I believe that don't need high power output. I prefer to listen liquid drum and bass and house music. Many thanks and regards, Pavol

  • Buck Pomerantz from Crutchfield

    Posted on 6/26/2015 3:19:42 PM

    Pavol, Almost all car audio systems benefit by the addition of an amplifier in musical clarity, energy, and loudness. While your sound will improve with the installation of those speakers alone, it will improve even more if you drive each of them with 50 to 75 watts RMS.

  • Jazzy Blue from PHILADELPHIA

    Posted on 7/5/2015 2:10:28 PM

    I have a 2014 Chrysler 300 w Beats audio...I love the sound at high volume but need a way to improve sound at lower volume. Will sound processor fix this problem and increase factory bass?

  • Buck Pomerantz from Crutchfield

    Posted on 7/7/2015 11:48:49 AM

    Jazzy, The sound quality of almost any system will benefit from the addition of a sound processor. From your description, it sounds like your premium system changes tone as the volume changes. A processor like JL Audio's CleanSweep compensates for this effect, resulting in a flat signal that you can EQ to your own taste. Almost any processor will allow you to set the tone the way you like at the volume you like.

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