Bringing back an old thread. I want to do something like this in my 2022 Hyundai Elantra. I am just adding a little AudioControl 300.1 and a Kicker downfiring 8. So I want everything to be unseen. I will probably route my wiring behind the carpet.
Sorry I haven't been on. Is the window of the avalanche out as well? If so, definitely getting cancellation. Open the bed of the truck and see if it gets louder. Looks like you have a camper/topper on the avalanche
It looks like the subs are firing into the car and not towards the trunk?
If I am seeing this right, try this?
Listen to one of your songs, then open your trunk. If it gets louder, your subs are cancelling because they are not completely sealed from the trunk.