Upgrade Your Car's Sound

The dash of the Kia Soul we used in our Helix Plug-and-Play installation

Factory stereo systems leave a lot to be desired. They’re often programmed with equalization (EQ) curves that compensate for the system’s lack of power by reducing the level of the bass, for instance. And because the speakers are all located at different distances from you, the sound arrives at your ears at different times, making your music sound a little muddy. Often, the best solution is to replace the factory stereo, but the dash designs of some vehicles can make that option difficult, or less than desirable.

Custom sound system upgrades to the rescue

Luckily, this problem has some solutions that let you keep your factory stereo and get spectacular sound, customized for your specific vehicle. The four upgrade systems we discuss in this article improve the factory sound of different vehicles in different ways — you can call us if you need a hand deciding which will work best for yours.

Keep your dash intact

In addition to improving the sound to match your vehicle’s size and shape, these upgrade systems are “stealthy,” in that they’re designed to fit in your vehicle with no visible modifications to its interior, except for the addition of a subwoofer.

Option 1: Helix Plug-and-Play upgrade systems

The Helix Plug-and-Play system

Helix transforms your sound

A Helix Plug-and-Play upgrade system turns your car into a hi-fi listening space using a tiny digital processing unit with a built-in 5-channel amplifier. Once you install it, you download vehicle-specific programming from Helix’s site onto a microSD™ card, then load it into the processor. This aligns the sound for the driver’s position, and adds power and proper EQ settings, giving your music unpre­cedented clarity and impact.

Martyn in his 2010 Kia Soul

We couldn’t wait to give it a try

We’d heard a demo of what a Helix upgrade system can do, so we were thrilled to learn we were adding them to our brand lineup. We made Martyn, Crutchfield’s Photo Studio Manager, the lucky recipient of one of these upgrades for his 2010 Kia Soul. We pulled his radio out, plugged the Helix system in without cutting any wires, positioned the subwoofer in the rear, and put it all back together.

Centered for the driver’s ears

Martyn noticed the corrected sound alignment immediately. “Is the music supposed to move over to where I’m sitting? ’Cause that’s what it sounds like — from the center of the car over to where I’m sitting. It’s amazing. And I love the sub, it adds a lot to my music.”

"The original sound was okay, nothing spectacular. Now, it’s awesome." Just adding the subwoofer would make a big improvement, but the Helix processor also clarifies and enhances the musical details.

A major sound improvement

We performed an RTA (real time analysis) on Martyn’s system before and after we installed the Helix upgrade to measure the improvements that took place. The difference is night and day. Martyn now gets better bass and treble response, with an increase in overall sound levels.

The grey curve is the original sound performance on the factory system. The yellow curve is with the Helix system installed. The Helix processor makes the factory stereo and speakers sound better. If Martyn were to install new speakers, those mid- and high-frequencies would likely smooth out a little.

System components

We used the following components for Martyn's installation:

• Helix PP50DSP digital signal processor with a built-in 5-channel amplifier
• Helix PP7E vented enclosure with two 7" subwoofers
• Some vehicles will also need a Helix PPAC vehicle-specific wiring harness, but it wasn't necessary for the 2010 Kia Soul
• A Maxell microSD™ card to store the vehicle-specific sound settings from Helix's website

Get a Helix system upgrade for your car

Helix presently has upgrades ready for quite a few popular, late-model vehicles. Call us, or use our vehicle selector to find the Helix upgrade for yours.

Option 2: Soundgate™ Powerstage™ by Kicker

Powerstage system for the 2012 Ford Mustang

Custom fit and programmed to make your vehicle sound great

A Soundgate Powerstage system upgrade by Kicker will transform your vehicle's stock radio and speakers into a high-fidelity sound system capable of giving you full, accurate, and richly textured music. And it does it without changing the look of your car's interior or dash.

It plugs into your factory wiring with no cutting

The heart of the system is the Powerstage processor/amp module that plugs in between your car's stock receiver and speakers with the help of a vehicle-specific wiring harness. Kicker's technicians measured the acoustics of the specific vehicle's interior, then developed a program to get the strongest and cleanest audio performance possible from the stock speakers. The Powerstage module breathes new life into your vehicle's factory system, automatically correcting for the limitations of the factory speakers, then adding plenty of power so the speakers can sound their best.

Of course, there's a subwoofer with it

Powerstage subwoofer for the 2012 Mustang

Powerstage subwoofer installed in the Mustang

A powered subwoofer, built to fit exactly in your vehicle, supplies the bass you need for fully balanced music. Soundgate upgrades come with all the wiring pre-cut and terminated to make installation easier. Step-by-step, illustrated instructions make this sonic upgrade a fun and rewarding project.

They’re currently available for many Chevrolet, Dodge, Ford, and Jeep vehicles. Use our vehicle selector to see if there's a Soundgate system available for yours.

Option 3: JL Audio StealthMod™

Add power and components to improve your sound

Stealthbox subs for the Camaro

A JL Audio StealthMod upgrade system works by replacing a few key components from the factory system, then adding an amplifier and a custom-fit Stealthbox® subwoofer to create a more powerful and better-sounding setup. Each StealthMod upgrade uses a different, custom-designed strategy to add power and improve the sound in the vehicle in which it works. Each package includes all the wires and hardware needed for a custom-fit, stealthy installation, along with photo-illustrated, detailed, step-by-step instructions.

Here are some examples of the vehicle-specific, customized approach JL Audio uses for these upgrade systems:

The StealthMod upgrade for a 2010-up Kia Soul (coming soon) adds a Stealthbox subwoofer with one 12" sub, a 3-channel amplifier, and a pair of full-range speakers.

The StealthMod upgrade for a 2011-up Chevy Camaro adds a Stealthbox subwoofer with two 10" subs, a 5-channel amplifier, a pair of component speakers, and modifies the factory tweeters.

The StealthMod upgrade for a 2007-up BMW X5 adds a Stealthbox subwoofer with one 10" sub, a 5-channel amp, a signal summing interface module, a pair of tweeters, and a new crossover.

Stealthbox subwoofer for the BMW X5

Subwoofer installed in the BMW X5

Option 4: Sony Digital Link Sound System

Sony Digital Link Sound System

Adds a source, a subwoofer, and upgrades the sound

A Sony Digital Link Sound System gives you a tremendous upgrade in the quality of your sound, and lets you play your iPod touch® or iPhone® through your car’s factory stereo at the same time. The XDP-PK1000 package includes a digital sound processing module with a built-in 4-channel amplifier for powering your factory speakers, a 12" subwoofer, a 300-watt subwoofer amp, and a dash-mountable cradle for your iPod. The XDP-MU110 version leaves off the subwoofer and amp.

The Sony Digital Link Sound System works with almost any basic factory system. You select your vehicle’s size and subwoofer location, and the digital signal pro­cessor adjusts the sound, lining up all the speaker and sub outputs to hit you at the same time for an incredible improvement in acoustic clarity.

Installing the Sony DLSS was a bit complicated

Lots of hard-wired connections to make

Installing this upgrade was a bit complicated, because it involved cutting into the wiring harness behind the radio, and making nineteen new connections in a very tight space. Two of the installers, Writer Jon and Advisor Trainee Crystal, accomplished this with great teamwork, methodically keeping track of where each wire came from and what it was supposed to be connected to.

We took it for a spin in a Honda CRV

We installed a Sony Digital Link upgrade in the Honda CRV that belongs to Tommy, a Crutchfield Advisor trainee. Tommy used to be a jazz radio announcer and cares more for high-fidelity sound than panel-rattling volume. “The sound quality has definitely improved, that’s obvious from the moment you turn it on. It’s now more full and present, and much more crisp and clear than before. When I’m listening to rock or R&B, the sub can boom if I want it to — the remote makes it easy to respond to different music choices — but the sealed Sony box allows for more musical sound reproduction on an acoustic bass.”

Tommy with his Honda CRV

Tommy keeps his iPhone cradle in the cupholder by his seat. He also has the option of mounting it on the dash.

"I like the sound now better than my factory system, for sure. Bass performance improved dramatically.  I have to manually switch between the system and my factory unit if I want to access other sources like CDs or the tuner, but that’s pretty easy to do. The sound-staging is good. Even with the sub off, however, I get a much more accurate and encompassing sound out of the original speaker system. My son’s reaction: ‘Too loud, daddy!’ My wife’s reaction: ‘Awesome!’"

These are just four ways to add improved sound to your car without changing the factory stereo. For more ideas, check out the Factory Radio Improvement section of our website, or give us a call and talk to our knowledgeable advisors. They'll help you figure out the options available for your car.