2011-2014 Cadillac CTS coupe

Overview of the Cadillac CTS coupe

The CTS sedan and wagon are excellent examples of their respective categories. The sedan is a spacious, luxurious, and impressive-looking vehicle, while the wagon is all that and more, plus cargo space. The coupe, which arrived a year later, is something else entirely. And what a brilliant thing it is.

Sedans and wagons, even cool ones like the CTS models, are designed to hold people and stuff as efficiently and comfortably as possible. If they offer any style at all (which those two do), that’s a bonus. Coupes, on the other hand, are all about style and exclusivity, and the CTS coupe offers gobs of both. Compared to the average off-the-rack coupe, this car is like Fashion Week in Milan on wheels.

You will not see yourself coming and going in this car, which is part of the joy of owning it. But if you care about what you hear when you’re scything through lesser vehicles, you’ll want to make some alterations to your sound system. This article will explain what you can do and how it’s done, and our experts can tailor a system that suits your unique tastes.

You can replace the CTS coupe's stock radio with a variety of aftermarket single-DIN (2" tall) or double-DIN (4" tall) aftermarket models (Crutchfield Research Photo)

The factory stereo system

The CTS coupe’s factory systems consist of a standard Bose system, and the top shelf 10-speaker Bose® 5.1 surround system. None of them are exactly bad, but at this point, they’re getting a bit dated. If you want to bring better sound to your car, you’ll need to upgrade.

Whether you’re starting with the base system or the Bose surround system, new aftermarket gear will give you more power, more clarity, and better performance overall. The project can be done in stages or all at once, and if you’re doing it yourself, Crutchfield’s legendary disassembly instructions and free tech support will help you get the job done right.

Before you start the job, though, make sure you set the car’s parking brake and disconnect the negative battery cable to prevent any electrical shorts. Refer to your vehicle's owner's manual for information on disconnecting the battery.

The radio removal process is reasonably uncomplicated in the CTS coupe (Crutchfield Research Photo)

Removing the factory radio

You can replace the stock radio with a nice variety of aftermarket single-DIN (2" tall) or double-DIN (4" tall) aftermarket models. You’ll save a bit of money on the dash kit/wiring harness combo you’ll need to install the new piece when you order from Crutchfield, too. You may need to make a few minor modifications to get the new receiver to fit properly in the dash kit, but the mods are minor and you’ll be able to handle it. Trim packages in gloss black and silver are available to fit an aftermarket stereo for the CTS coupe.

The aftermarket interface will retain your car’s Bose® and OnStar® features, including the warning chimes. Before you order, though, check the sticker located under the car’s spare tire cover. If you see the RPO code "UQS," your vehicle has a digital amplifier and you’ll lose fader and balance functions when you replace the factory radio. If you don’t see that particular code, you'll retain those functions.

Detailed stereo and speaker removal instructions

With step-by-step disassembly instructions and plenty of up-close, detailed photos, our exclusive Crutchfield MasterSheet™ takes the guesswork out of removing the factory stereo and speakers. It's free with your Crutchfield order, or you can purchase one separately for just $9.99.

The removal/replacement process is reasonably uncomplicated in the CTS coupe, and you can do the job using basic tools you probably have already. You might not have a panel tool, though, and if you need a set, you can add it to your Crutchfield order.

That order will include our free disassembly instructions, which will provide the illustrated, step-by-step guidance you’ll need to remove the stock gear. The dash kit/interface will include its own installation instructions. Once you’ve installed (and tested!) the new radio, you can put everything back together by reversing the disassembly steps.

Tools needed: Panel tool, 7mm socket, ratchet and extension, clean shop rag

Read our Car Stereo Buying Guide for shopping tips and advice.

Shop for car stereos that fit your Cadillac CTS

Steering wheel audio controls

In most cases, it's reasonably easy to retain your Cadillac's steering wheel audio controls when you install a new stereo. When you enter your vehicle information, our database will choose the adapter you need to make your factory steering wheel controls work with a compatible aftermarket receiver.

Replacing the speakers will seriously improve your car's audio quality (Crutchfield Research Photo)

Removing the factory speakers

Even if you decide to keep the factory radio, you can improve your car's sound with new speakers all around. The work isn't always easy in the CTS coupe, but it's still well within the capabilities of a reasonably skilled DIY-er.

The center dash speaker is pretty easy to deal with in the CTS coupe (Crutchfield Research Photo)

Removing the center dash speaker

All CTS coupes have a 3-1/2" center dash speaker, and it’s quite easy to reach and replace. Starting at the top edge, use a panel tool to pry out the pillar trim panel and release two clips. Push the retainer strap in to release it, then lift the trim panel and remove it. Next, you’ll repeat these steps on the opposite side of the vehicle.

Pry up along the rear edge of the grille/vent panel on top of the dash to release ten clips, then disconnect the harness and pull the panel toward the rear of the car to remove it. Remove the two 7mm screws securing the speaker to the dash, then disconnect the harness and remove the speaker.

You can use the factory speaker grille to cover the new speaker, but a wiring harness is not available. You'll need to splice, solder, or use Posi-Products speaker connectors to connect the new speaker to the car’s wiring.

Tools needed: Panel tool, 7mm socket, ratchet and extension

The corner and center dash speakers are all located under the same panel (Crutchfield Research Photo)

Removing the corner dash speakers

The base system sports a pair of small corner dash tweeters, while the Bose system ups the ante with a pair of 3-1/2" speakers. Getting to these speakers is pretty easy, and if you decided to replace the center dash speaker, you’re already most of the way there. Once that dash panel is out of the way, all you have to do is remove the two 7mm screws securing the speaker, disconnect the harness, and remove the speaker.

Regardless of what you’re replacing, the factory locations will accept 3-1/2" speakers. If you’re installing new tweeters, you might be able to get away with modifying and reusing the stock brackets, but you’ll probably need a set of our universal backstraps. They’re not at all expensive, so it’s probably best to toss a set into your cart just in case. They have other uses, too!

If you’re upgrading the corner speakers in a CTS equipped with the Bose 5.1 system, there’s no wiring harness available, so you’ll need to splice, solder, or use Posi-Products speaker connectors.

Tools needed: Panel tool, 7mm socket, ratchet and extension, bit to modify stock brackets

The stock Bose systems feature woofers in the doors (Crutchfield Research Photo)

Removing the Bose® door woofers

Both of the factory Bose systems include speakers in the big, long doors. These speakers can be replaced by a variety of 5-1/4" or 6-1/2" speakers, but be advised that these speakers only receive bass frequencies from the stock amplifier. If you’re going to use that stock amp going forward, anything you install here will only reproduce bass frequencies.

You’ll need to remove the door panels to access these speakers, and while that’s not hard, there are some minor process differences depending on what you’re starting with. You can find all the details in your Crutchfield disassembly instructions.

With the Bose 5.1 system, you’ll need to use mounting brackets to install the new speakers, and you’ll need to drill new mounting holes for the brackets. This isn’t hard, but work carefully, know what you’re drilling into, and definitely wear eye protection.

Once your speakers are connected and secured, you’ll want to test them before you put the doors back together. Also, check that the wires do not interfere with window operation and test the door lock and release operation. If all is well, start putting the doors back together.

Tools needed: Panel tool, #3 Phillips screwdriver, flat-blade screwdriver, 7mm and 1/4" sockets, ratchet and extension, drill and 1/8" bit (Bose 5.1), pliers

Getting to the rear side speakers is not the work of a moment (Crutchfield Research Photo)

Removing the rear side panel speakers

Like many coupes, the CTS has speakers in the rear side panels. And like many coupes, the removal and replacement process takes a minute – to put it mildly. It’s not that the work is ridiculously challenging or anything, it’s just that there are several steps involved and you’ll be removing a fair number of screws, nuts, panels, and plates, not to mention the bottom seat cushion.

Don’t let this discourage you, though. This is still a thoroughly do-able project for the DIY-er. You’ll just need to work patiently and keep all those parts and pieces organized. When it’s time to put everything back together again, you’ll be glad you did.

You can replace the stock 5-1/4" speakers with a variety of same-size aftermarket models. Once they’re connected and secured, test them out before you start reassembling the area. Make sure the seats and seat belts are secured properly before you hit the road again.

Tools needed: Panel tool, 7mm socket, ratchet and extension, 10mm and 15mm deep sockets, small flat blade screwdriver, Torx T-15 driver

In Bose-equipped cars, you'll find speakers in the rear deck (Crutchfield Research Photo)

Removing the Bose® rear deck speakers

The biggest Bose system (aka the 5.1) adds rear deck speakers to the mix, specifically a 12" (-ish) subwoofer and a pair of 2.457" tweeters. You’ll need to do a lot of the same stuff that’s involved in accessing the rear side speakers, so if you’re upgrading your car’s 5.1 system, you might want to do those and these at the same time.

Again, the process isn’t hard, but patience and organization will be rewarded. Replacements are available for all three deck speakers, but there are no speaker wiring adapters available at this time, so you’ll need to splice, solder, or use Posi-Products speaker connectors.

As for mounting them, there are no brackets for the tweeters, so you’ll need to make your own or (better idea) use our universal backstraps. There are no direct-fit subwoofers, but we can help you choose something that will work back here. You’ll need to drill new mounting holes, so work carefully, know what’s around the drilling area, and wear eye protection.

Crutchfield’s exclusive step-by-step disassembly instructions will be included with your order, of course. If you have questions, your order also includes free tech support for the life of your gear. Our experts are right here in Virginia and ready to help.

Tools needed: Panel tool, 7mm socket, ratchet and extension, 10mm and 15mm deep sockets, small flat blade screwdriver, right-angle or stubby Phillips screwdriver

Read our Car Speakers Buying Guide for more information

Shop for speakers that fit your Cadillac CTS

There's a decent amount of space for a subwoofer enclosure in the CTS coupe's spacious trunk (Crutchfield Research Photo)

More bass in your CTS coupe

If you want to go big on bass, the CTS coupe gives you some room to work with. The trunk isn’t huge, but it is high and deep, which really helps. We measured the usable space as 34"W x 17"H x 28"/36"D, which should be plenty of room for a subwoofer enclosure.

If you want better bass, but still want to retain your cargo space, a more compact powered subwoofer might be the solution you need.

Learn more about building a bass system in our Car Subwoofer Buying Guide.

Installing Dynamat in your CTS coupe will help seal in sound

Other options for your CTS coupe

There are plenty of other ways to improve your CTS. Here are just a few of them:

Add an amp (or two)

A new 4-channel amplifier will help you get the most out of your new speakers. You'll get cleaner power (and a lot more of it), which will result in much, much better sound. A mono amp can provide the juice you need for your new subwoofer, too. You can learn more about adding amps to your Caddy's system in our Car Amplifier Buying Guide.

Dynamat

The Dynamat 10435 Xtreme Door Kit is the perfect way to seal in sound. This heavy-duty insulating material is easy to install, and it really makes a difference. One kit should take care of the front doors. If you install a big sub, you might want to line the trunk lid as well.

Remote start and security systems

You can also talk to your Crutchfield Advisor about a security system. They’re not as easy to install (we usually suggest letting a professional do the job), but we can help you choose a system that’ll work in your vehicle.

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