Port on angle effect Hz?

[Rob93]

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?

Click to read more...

 

[fithwheel]

Did you design the box? If so how did you figure the port height? You can use test tones to get a pretty good idea of where it's tuned at.

 

[Jeffdachef 5,000+ posts]

the way you have the box facing can and will determine your frequency response. Some directions give different levels of cancellation. I'd recommend having the sub and port fire backwards 4-6 inches from a soid loading wall preferably farthest away from you aka the rear hatch for best results. The farther you move from the hatch, the worse the issue is going to get for a bigger car.