2020 GMC Sierra 1500 AT4 Stealth Bass Upgrade

Factory audio systems have come a long way, but they're often missing one thing—real bass. This GMC Sierra 1500 AT4 came to Sound Connection looking for a low-profile upgrade that would dramatically improve the listening experience without sacrificing the truck's factory appearance.

To accomplish that, we installed a custom under-seat subwoofer enclosure, providing deep, accurate bass while keeping the rear seating area completely functional. The compact enclosure fits neatly beneath the rear seat, making the entire system virtually invisible once everything is buttoned back up.

To power the system, we added an audiocontrol amplifier, securely mounted behind the rear seat for a clean, protected installation. Rather than replacing the factory radio, we integrated the new equipment using a line output converter (LOC), allowing the factory infotainment system to remain fully functional while delivering a clean audio signal to the amplifier.

The result is a dramatic improvement in overall sound quality. Music gains the low-frequency impact the factory system was missing, while maintaining the original look, features, and convenience of the truck's OEM audio system.

Whether it's country, classic rock, hip-hop, or podcasts on the daily commute, this Sierra now has the balanced, full-range sound every premium truck deserves.