A client from here in Richmond recently brought his 2025 GMC Sierra Denali to Extreme Audio for an audio system upgrade. He is a old-school R&B and jazz fanatic and was unhappy with the sound of the factory-installed stereo. We invited him to listen to our shop truck that uses Audiofrog speakers. The sound was exactly what he wanted. However, he asked that we use factory-speaker locations so as to limit the modifications to the vehicle. With a plan in place, we scheduled an appointment to begin the upgrade.
Audiofrog Speaker Upgrade
We started the upgrade by creating new mounting adapters for the doors to install GB60 6.5-inch woofers in place of the factory-installed 6x9s. We added SoundShield sound deadening around the adapter and speaker to ensure a 100% airtight seal.
Next, we moved to the dash, where we installed a pair of GB25 2.5-inch midrange drivers. We made a mounting plate for a GS25 midrange driver to fit in the center channel location. We used the GB10OE tweeters and installed them in the factory locations in the A-pillars. These are the same motor and diaphragm design as the GB10 tweeters, but the outer housing is removed so we can fit the drivers into factory locations more easily. To round out the system we installed GS60 woofers and GS10 tweeters in the rear doors.
For bass, we installed a JL Audio SB-GM-SLVCC4/12TW3/BK Stealthbox subwoofer enclosure under the rear seat. This beautifully crafted fiberglass enclosure houses a pair of JL Audio 12TW3 high-performance shallow woofers. As you can see, the enclosure not only fits perfectly but also allows storage under the passenger-side seat. JL Audio puts a lot of effort into ensuring the enclosure’s carpet matches the factory carpet, and this attention to detail is much appreciated.
ARC Audio System Amplifiers
A pair of ARC Audio amplifiers power the Denali stereo system. The main amp is a 12-channel Falcon, and we added a two-channel Nighthawk to power the JL Audio Stealthbox subwoofer enclosure. The Falcon amplifier has a powerful digital signal processor on board that we used to route signals from a PAC Audio AMPPRO AP4-GM71 interface. Specifically, we used upmixed the stereo signal to feed the new center speaker. Using the AMPPRO meant we didn’t need to deal with warning chime and bass roll-off issues. The Falcon is conservatively rated at 75 watts per channel, while the Nighthawk delivers over 1,000 watts and ensures the client gets great sound from the subwoofer system.
We mounted the amplifiers to the truck’s back wall on a carpeted panel, and all the wiring to and from the amps is secured to the panel to prevent rattling or buzzing while the truck is in motion.
System Configuration and Calibration
With everything installed and the truck back together, our team set up our RTA microphone to measure each speaker’s output and observe how it interacted with the vehicle interior. We used the ARC Audio DSP software to compensate for the vehicle’s acoustics and delay the signal to the speakers nearest to the driver so he would hear everything at once. This calibration produces a soundstage that spans the windshield, making it sound like he’s sitting front-row at a live concert.
Richmond’s Best Car Audio Upgrades
The client returned to Extreme Audio, anxious to hear the new stereo system in his Sierra Denali, and he was thrilled with the sound and output capability. He loved that all the speakers are hidden behind the factory grilles and that the subwoofer enclosure looks like it belongs.
If the stereo system in your truck doesn’t give you goosebumps when you crank it up, drop by Extreme Audio in Mechanicsville or Midlothian and speak with a member of our team. We can design and install a system that will put a smile on your face every time you get in the truck. If you can’t get to one of our stores during regular business hours, please call the location nearest to you or send our team an email using the contact form, and we’ll get back to you as quickly as possible.
Did this Sierra have a Bose system