Hi all, I have made 3 different boxes of varying sizes all different, but same style with the port on the angled back against my third row, customized for different subwoofers. Two were rear firing for a Skar DDX12, my current one is downfiring for a Skar VXF12. Current box is 2 cubes, I’ll attach a picture from the plans for the current box to get a more specific idea. All of the boxes I have made with my max dimensions have sounded like they are tuned higher than they were intended, could this be because my port is on an angled side? I saw some manufacturers have the port on on their pre fab boxes on the angled side throughout the whole length, not like mine, does a port on an angled side effect anything?

I am wondering because I still want to hit lower around 30hz but it sounds for the third time like I am tuned around 40hz with a box that is supposed to be tuned to 30.


Should I build another box with the port not on any slanted walls(side firing on wall closest to trunk gate farthest from slant with subwoofer on slant)? Should I get rid of the slant entirely? Is it the subwoofer brand skar? I really wanna hit low, can someone that knows more than me tell me which of my solutions would get me there?