I have a 2021 GMC Sierra 3500 AT4HD and just wrapped up my sub install.
My truck has factory Bose, and to my ears it just sounded muddy in stock form.
At the end of June, Crutchfield received a shipment of JL Audio Stealthboxes, and I quickly ordered one. They’re long since out of stock again.
To power it, I went with an Audio Control LC-1.800 subwoofer amplifier. It pushes 800w at 2 ohms and the Stealthbox is wired for 2 ohms with the JL Audio 12” 12TW3-12 subs. The amp can accept high level speaker inputs, so there was no need to install a line out converter. I also installed the Audio Control LC1 remote bass knob and Crutchfield was the source for 4AWG wiring kit.
To get the signal, I picked up an LLJ Customs T harness and extended the speaker wires.
Now that my install is complete, I’ve dialed the bass to “0” on the head unit, and it sounds so much clearer without the Bose speakers trying to handle the bass.
The JL subs hit crazy hard, especially for shallow depth subs. The Stealthbox fit and finish is excellent too and it’s sized perfectly for the pair of 12s.
All types of music sound great - live concerts (Dave Matthews Band, Mumford and Sons), 90s rap (Dr. Dre, Warren G, etc), country, rock, alternative, current rap (Post Malone is about all I know!) - everything just sounds so much better.
Despite being a full width enclosure, there is a space to mount the amp, and since the Audio Control LC-1.800 isn’t huge, I even have room for some personal effects.