2003-08 Toyota Corolla

Overview

The 2003-08 Toyota Corolla is an economical car with a high reliability factor. If you've picked up a used Corolla and you're checking out your audio options, we've got lots of good news for you. First, you bought a nice car. Second, you can install a great stereo system in this vehicle.

2003 Toyota Corolla with 6-speaker system (Crutchfield Research Photo)

Toyota offered a basic 4-speaker system and an upgraded 6-speaker system that adds tweeters in the front door sail panels. You’ll rarely see the JBL sound system that Toyota offered for the 2005-08 Corolla, and we don't have a lot of information about the speakers in that setup. If you’re interested in upgrading your audio system, you can easily replace the radio and speakers in the 4- and 6-speaker systems, and the radio in the JBL version.

Replacing your factory radio

Factory radio in 6-speaker system (Crutchfield Research Photo)

4-speaker and 6-speaker system
A new car stereo will always make your factory speaker system sound better, plus it allows you to add new features like iPod® control or HD Radio™ reception. You’ll need a dash kit to install a DIN (2" tall) or double-DIN (4" tall) radio. It’s possible to hard wire a new stereo to the factory wiring but getting a wiring harness will keep you from having to cut into the factory wires. (Crutchfield includes the dash kit and harness needed for this installation free with most orders, along with our step-by-step instructions for your Corolla.)

If you want to keep the factory look, you’ll find inputs on the rear of the Toyota radio that make it easy to add additional features. You can add an adapter that allows you to control your iPod with the controls on the Toyota radio, and another adapter that allows you to make hands-free calls through the factory radio. You can build a full system around the factory radio with new speakers, amplifiers, and subwoofers, but an aftermarket stereo will give you a cleaner sound that will make these upgrades sound even better.

Installation Notes: You can’t install a double-DIN receiver with a fold-down face in this car. If you have the Toyota satellite radio option, you’ll lose it when you install a new stereo.

Corolla dash disassembled (Crutchfield Research Photo)

JBL System
The JBL logo on your radio tells you that you have the upgraded Corolla system. The JBL system is so rare that we haven’t been able to research its speaker configuration. You may want to speak with a professional installer if you wish to replace your factory speakers in this system.

You’ll need the same dash kit to replace the radio in the JBL system, and you’ll also need a special wiring harness that retains the JBL amplifier. You’ll probably want to keep  the JBL amplifier unless you’re prepared to run speaker wires from your new radio to each of the speakers, which is a time-consuming job. You’ll usually hear improved sound quality when you install a new car stereo, because it’ll send a cleaner signal to the JBL amp. Crutchfield offers a Toyota Factory Integration Adapter that plugs into the factory harness and keeps the JBL amplifier working. (Crutchfield offers a 50% discount on this special adapter when purchased with any car stereo, but we include the mounting kit and our step-by-step instructions for your Corolla free with most orders.)

Note:  You will need to have an aftermarket stereo with two pairs of preamp outputs to connect the special JBL adapter. If you have the Toyota satellite radio option, you’ll lose it when you install a new stereo.

Tools needed for installing new stereo:

• Phillips screwdriver
• Small flat blade screwdriver
• 10mm socket ratchet & extension
• Panel tool

Replacing your factory speakers

Front door in 4-speaker system (Crutchfield Research Photo)

Basic 4-speaker system

This basic system comes equipped with 6-3/4" speakers in the front door and 6"x9" speakers in the rear deck. Toyota uses 4-ohm speakers up front and 6-ohm speakers on the rear deck, so almost any aftermarket speakers will work well with the factory radio, excepting certain high-performance speakers that really need an amp to be happy.

Front Doors
The Toyota’s front door houses a 3-bolt  6-3/4" speaker, and there’s no direct replacement. You can install a 6-1/2" or 5-1/4" speaker in the front door with the help of a mounting bracket, but you’ll need to drill some new screw holes to mount this bracket.  No offense to Toyota, but the stock front speakers aren’t the greatest, so you’ll experience a big jump in sound quality when you install some new speakers.

The factory 6-3/4" speaker (Crutchfield Research Photo)

You’ll have to remove the door panel to get at the factory speaker, which is attached to the door with three rivets. You’ll need to drill out the rivets to remove the speaker, so make sure you have the right tools for the job. Since the factory speaker is molded to a bracket in the door, you will definitely need a new bracket to mount any aftermarket speaker. Wiring harnesses are available to connect the new speaker to your factory wiring. (Crutchfield includes speaker harnesses and mounting brackets free with every speaker order).

Corolla rear deck speakers (Crutchfield Research Photo)

Rear deck speakers
You’ll find 6"x9" speakers on the rear deck in both speaker systems. To access this location, you’ll have  to fold down the rear seats and remove the rear pillar trim. You can then remove the rear deck panel. You can install a 6"x9" speaker in the rear deck, or a 6-1/2" or 5-1/4" speaker if you use a mounting bracket. You’ll need to drill holes in the rear deck to install aftermarket speakers, and the angle of rear window makes this job very difficult. There will be a bit of a gap between the speaker and the rear deck or the bracket, so we recommend using a speaker baffle to fill in the gap. You will want to cut off the bottom of the baffle and use the remaining portion as a gasket.   

The factory rear deck 6"x9" (Crutchfield Research Photo)

6-speaker system

The upgraded 6-speaker system adds front door tweeters to the standard 4-speaker system and accommodates the same size speakers. You may be able to use the factory tweeter mounting bracket when installing new tweeters as long as your aftermarket tweeters have a threaded insert on the back.

6-speaker system front door tweeter (Crutchfield Research Photo)

 Tools needed for installing new speakers:

• Phillips screwdriver
• Small flat blade screwdriver
• 10mm socket ratchet & extension
• Drill & 1/8" bit with right angle adapter
• Panel tool
• Shop rag

Adding Bass to your Corolla

4-speaker and 6-speaker system
The Corolla comes with a decent-sized trunk so finding room for a subwoofer and amplifier (or a powered sub) won’t be a problem. You can use the wiring of the rear deck speakers to get a signal to your sub system. There are a couple of other options if you need all your trunk space. You might find a small powered sub that’ll fit under one of the seats. Or, fortify the rear deck with Dynamat or some other noise killing material so it will handle the bass without rattling, and install some smaller subs back there.

More options

Amps
Powering your new speakers with an amplifier will give you an enormous boost in sound quality, regardless of sound system. We don’t recommend using an amplifier with your factory speakers as they aren't designed to handle that kind of power.

Digital Signal Processor
If modifying your ride just isn't in your DNA, Helix offers another option for vehicles without factory amplifiers. You can use their PP50DSP processor to make a dramatic improvement in the sound of your factory system. It works like this: you buy the processor, along with a vehicle-specific cable and a plug-in powered sub. The cable plugs into your factory radio's plug, connecting the processor/amp to your factory speakers. Next, go to Helix's site, download your vehicle’s audio parameters onto a microSD card, then load that info into the amp/processor. The PP50DSP is now ready to use equalization and time alignment to make your factory speakers sound great. Add in the bass from the optional Helix sub, and you've got a total system upgrade with minimal work.

Satellite Radio
You can add a Dock-and-Play satellite radio that you can take from car to car. If your factory radio came equipped with satellite radio, you will lose that option with a new car stereo, so look for a new radio that’ll work with an outboard SiriusXM tuner.

Navigation
Any aftermarket in-dash navigation receiver will fit in the Corolla, as there’s plenty of room behind the dash.

Security
It’s relatively easy to add security or remote start into your Corolla.  All connections are made under the driver’s side dash, and in the driver’s side kick panel area.  This US version of the Corolla is not equipped with a transponder key; however, 2005-08 Canadian models will require the use of an XK05, PKFM, or FLCAN for transponder bypass.  All three modules offer the same end result, we however suggest the FLCAN if needed because of the advanced mapping they use on their Toyota firmware.