Trunk wall is basically forward firing sealed off from the trunk?

correct.

Is it loud though? Does it sound like a normal system or is it just not as loud on those frequencies?

It's loud. Sounds normal. Actually kinda clean sounding to me. But I would like it to excel in the lower frequencies. The fact that I throw my box in my friends car and it sounds so much better makes me want more from my gear in my vehicle

Ok because I was going to see if it was the rcas or the amp. I've seen both screw up the sound of the system.

Amp maybe, Rcas I hope not. Brand new knu karma rcas. I have a bnib crescendo bc2000 in the garage. Maybe I should slap it in. My sundown is old and kinda beat on.

Try the crescendo. You never know it could somehow be the amp.

 

With the low end in my experience I've always had the best results from larger lower tuned boxes.

Box is about as big as I can go with it and still get it in there. I thought it may have been the remaining trunk space after the box was in there was my problem. When the box is in its a tight fit all around. Passage space for air to travel to the front of the car is very little. I threw a single 12 enclosure in there and had the same problem.

this is not always the case. my ethos in the same size box 3 feet tuned to 32 for the 15 has a flat response with a F3 of ~28. In the same size box tuned to 36 it gets ~3db gain from 30-50 with an f3 of ~29. going with a larger box with same tuning only results in a bigger peak at tuning frequency, not any more lower extension.

Large and low tuned to get that big peak down low.

With the low end in my experience I've always had the best results from larger lower tuned boxes.

Box is about as big as I can go with it and still get it in there. I thought it may have been the remaining trunk space after the box was in there was my problem. When the box is in its a tight fit all around. Passage space for air to travel to the front of the car is very little. I threw a single 12 enclosure in there and had the same problem.

this is not always the case. my ethos in the same size box 3 feet tuned to 32 for the 15 has a flat response with a F3 of ~28. In the same size box tuned to 36 it gets ~3db gain from 30-50 with an f3 of ~29. going with a larger box with same tuning only results in a bigger peak at tuning frequency, not any more lower extension.

Large and low tuned to get that big peak down low.

. Guess you didn't understand the post.