I'm thinking about building a new box for my 15" DC level 3. My current box is slot ported to the back with the sub firing up towards the trunk lid, 3.3^ft tuned to 32 hz. I was thinking about building a box firing into the cab (BMW 330CI). Im not too experienced with building boxes but think i can manage this. Has anyone here done this kind of box before and can give me any pointers?

 

You will get the most of your sub when you fire it and the port towards the rear in most CAR applications...this way you don't get "port noise" from the air, let's the sound waves reverb off of the rear of the car then the dash/windshield before it hits your ears and it gives the listener more of a physical experience, IMO.  There are videos on you tube about how to get the most, measured, spl out of your setup when positioning your enclosure.  You would gain spl by facing the sub and port to the stern I know that for sure(in a car). 

You will get the most of your sub when you fire it and the port towards the rear in most CAR applications...this way you don't get "port noise" from the air, let's the sound waves reverb off of the rear of the car then the dash/windshield before it hits your ears and it gives the listener more of a physical experience, IMO.  There are videos on you tube about how to get the most, measured, spl out of your setup when positioning your enclosure.  You would gain spl by facing the sub and port to the stern I know that for sure(in a car). 

That seems to be the common consensus when it comes to trunk builds. My buddy had his set up firing into the cabin with the trunk completely sealed off and i just loved the amount of air it generated so that was what i was going for but seems like the build might be a pain in the ass if it doesnt work out right.

You should grab a measuring tape and figure out max dimensions taking into consideration your trunk opening unless you plan to build inside the trunk. Maybe snap a couple pics.

In my 11 Malibu forward firing has sounded the best so far, as long as I lay the driver side rear seat down. Sounds like ass to me if the rear seats are in the closed position.

It all comes down to how it's done. I prefer having the sub and port firing directly into the cabin as you're wanting to do OP. The thing is they have to actually fire INTO the cabin, not just facing it in the trunk, and the cabin needs to be sealed off as well as possible from the trunk after doing so. To me it sounds 100 times more natural and the best part is that pretty much all the rattles that come from the trunk/rear of the car are gone.

As for the port noise, if the correct size/port area is being used no audible noise should be produced by the port itself. If you are hearing port noise then your enclosure design wasn't done correctly by calculating the vent Mach/port velocity and making sure it's within respectable limits.

Ill try to get some measurements tonight or tomorrow if its too dark. i was planning on doing a trunk wall and sealing it all off. I always have my seats down when im beating if not my rear deck lid goes insane.

Thanks for clarifying that Alton, at the moment I, personally, do have improper port tuning and internal box volume for my T1 and still have little to no port noise, however I do fire it all backwards, (other wise i'm sure I'd here a bit of it) but that is going to be rectified when my Fi BL and it's fancy new enclosure arrive!  I'm a lucky one as for trunk rattle as my Mazda Millinia doesn't have that issue very bad at all..wonder if it has to do with being the "L" version...anyways....

 

Thanks also for making note that since the OP prefers the sound and feel of the forward firing design to make sure and keep anything from blocking the driver and port. 

 

I don't have the option to fire forward as my back seat is two pieces, the bench and the back rest, and the back rest does not fold down.  So instead I have a nearly 1 foot square hole in the deck below my back window that air shoots thru when I'm poundin' It's sounds great and you can really feel the air come at you still.

 

I hope the OP can fit his desired enclosure design in his trunk opening while keeping the same volume.

 

(learning as I move a long in these forums is my intention!)

Edited March 14, 201411 yr by THX_Elite