I was measuring everything out the other day to design a box for my box and got stuck here... Anyone with any experience with large upward and rearward firing ported boxes in an xB? Going with a single 18 and my original idea was to have both the sub and port firing upwards but was curious what other configurations others have used successfully.

 

if you fire it back your hatch is gunna rattle bad if you got the space fire it into the back seat its nice and clean but not loud and as for the hatch if you can get sound deadening then itll be your best bet

 

Fire up. Most cars with similar shape work best firing up or back.

 

Tell that to my buddy with the 2 8" Diamond D3 8's I installed... Sealed enclosure is firing up out of a false floor with about 500watts for the pair of subs. Rattled the back panel enough where he had me remove it. I removed my rear panel after I noticed it making awful noises. Checked it out and it was moving a good inch back and forth rattling. Took it out.
^^^x2. My DD 9515G is sub/port up.

To the OP, what subwoofer are you considering?

 

Go with up. You'll rear panel buzz problems firing back. Remember to make the box fit the speaker internal volume (ie, cubic inches) and not the other way around. I'd also flare the ports (both inside and outside) for a cleaner sound. Looks better, too.

 

Using an 18" Beyond Audio Inhuman; Quad 1 ohm copper coils, double stiff spiders. Still have one new in the box from years ago that didn't make it into an install. Getting tired of looking at the box so I figured I would put it in mine, haha.

 

^ any pictures of that 18 in your box?

 

I say point it up or forward but for car shows to show it off if you do them point it back LOL!!!

 

Honestly, being the audio nerd that I am, I'd keep that Inhuman packed away in the closet. I'd scoop up something not as rare. They sold a few of them, back in the day, but not many are still around.

If you need help with box design, let me know.

 

Sub up port back. /thread

 

I have mine facing up!

 

at first had mines sub back port back hatch rattled like a **** then had it sub front port front no rattles it was clean but not loud then had it sub up port up only slight rattle from LED dome hitting housing but its mostly clean and hella loud but yes i believe sub up and port bach would work the best and you would be most satisfied with

 

If you do position the ports to the rear, you need to have a distance of 1-1/2x the port diameter between the port and the rear hatch. If it's closer, your port will see an air resistance and tune the box to a different frequency, costing you sound quality (your Theil-Small Parameters gets shot to bits). Typically, a 12" driver needs a 4" port, so your open space between the port and wall will be 8". I find it easier just to port up, since you have no obstructions.

 

Will do, and luckily, I've got two of them I'll keep one locked away for safe keeping.