Extraordinary GMC Sierra Stereo Upgrade for Finksburg Enthusiast

A client from Finksburg recently contacted the Westminster Speed and Sound team to inquire about an extraordinary audio system upgrade for his 2024 GMC Sierra 2500. Not only did he want the sound system to play much louder than the stock setup that came with the truck, but he also wanted a subwoofer system capable of delivering even the deepest bass notes with impressive authority.

We had worked with this client before, so we had a good idea of what he was looking for from this Sierra stereo upgrade. After discussing system design options, we compiled a proposal that checked every box on his wish list—and even exceeded his expectations. He loved the plan and gave us the go-ahead to begin this one-of-a-kind project.

Helix Digital Signal Processor Integration

Having worked on several late-model Sierras recently, we were well aware of the challenges posed by the factory stereo system. With that in mind, we based this stereo upgrade around a Helix VEIGHTDSP amplifier equipped with a digital signal processor. This DSP allows us to flatten the factory equalization and compensate for the all-pass filters present in the output of the factory source unit. In effect, it gives us a clean signal that closely mimics that of an aftermarket source unit. With this clean input, we can configure the new system to ensure its performance meets our high standards.

We added a Helix Conductor remote to the DSP and mounted it in the glove box. The client can use it to adjust the level of the subwoofer system with a simple push and twist of the knob.

GMC Sierra Speaker Upgrade

With the main processing and amplification solution in place, our team set to work replacing the factory speakers in the truck. We installed a set of 8-inch Helix i7 Series speakers in the stock door locations. Our technicians fabricated mounting adapters out of expanded PVC plastic to utilize the factory fastener locations. Next, we created custom mounting brackets for a set of 2-inch BLAM wideband drivers. These were installed in the factory dash locations, aimed inward and upward toward the windshield for improved staging and imaging.

To complete the speaker upgrade, we installed a set of BLAM Signature Series coaxial drivers in the rear doors, also using custom PVC adapters. While the doors were apart, we applied a full layer of Hushmat sound-deadening material to both the inner and outer door skins to reduce vibrations and enhance sound clarity.

We treated the outer door skin with Hushmat sound deadening.

Hushmat Sound Deadening helps keep the vehicle interior quiet.

The stock midrange dash speaker.

A custom acrylic mounting bracket cut using our in-hose laser engraver.

The BLAM wideband speaker on the left side of the dash.

A custom acrylic bracket allows the BLAM wideband speakers to bolt in place.

Coaxial rear speakers wrap the sound around the listening space.

Custom Pickup Truck Subwoofer System

When it came to fun factor, the highlight of this build was undoubtedly the subwoofer system. We began by installing a two-inch LMI Welding lift kit under the rear seat. A properly engineered subwoofer system requires an enclosure with sufficient airspace, and this modification provided the necessary space to achieve that.

We constructed a custom enclosure to house three Wavtech ThinPro122 12-inch subwoofers. These amazing slim-profile subwoofers offer several inches of excursion and can handle impressive amounts of power, proving that thin doesn’t mean weak. The enclosure features a bass reflex (ported) design to deliver both the impact and low-frequency extension the client wanted.

Each subwoofer is powered by its own Wavtech Link1000.1mini amplifier. With each amplifier delivering 1,000 watts of power, the subwoofer system boasts a formidable 3,000-watt capability.

To feed this power-hungry system, we installed a 12 amp-hour Limitless Sodium battery. We routed 0-AWG power and ground cables to the battery’s charging side and ran dedicated 4-AWG wires from the battery to each of the Wavtech amplifiers to ensure optimal current delivery.

The bottom of one of the ThinPro 12-inch subwoofers.

The top of one of the Wavtech ThinPro subwoofers.

The custom enclosure, ready for subwoofer installation.

The custom subwoofer ready to load into the GMC Sierra.

We added the Wavtech logo to the top of the enclosure.

The enclosure in the back of the Sierra.

We finished the enclosure in black vinyl to match the seats.

The back wall of the truck is home to 4 amplifiers and the additional battery.

Stunning Bass and Clarity in this GMC Sierra Stereo Upgrade

Once the system was fully installed, our expert technicians fine-tuned it by setting all crossover points, time alignment delays, and equalization parameters in the DSP to match our signature target response curve. The final result is both musically and dynamically engaging. With a quick twist of the Helix Conductor remote, the owner can boost the bass to thunderous levels reminiscent of the 1990s, when massive subwoofer installations were all the rage. These ThinPro subs move a serious amount of air!

The client was beyond thrilled with how the system sounds and performs. The ability to go from balanced and detailed to bone-rattling with a simple adjustment brought a giant smile to his face.

If the stereo system in your pickup truck isn’t delivering the excitement and clarity you crave, bring it to the experts at Westminster Speed and Sound. Speak with a member of our award-winning team to explore a custom upgrade tailored to your needs. If you can’t make it during regular business hours, please call us or use our contact form to email us. We’ll get back to you as soon as possible.

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