box ? for the experts

I'd definitely try facing the sub towards the back.  Over the years I've tried many different directions, and I found that a rear firing direction works best.  When the sub is facing upwards or towards the front you'll find that you get alot of woofer noise.  If I read your post right, you may want to try tipping your box over so your woofer is facing back and your port is aiming towards the floor (downfiring).  Just make sure you elevate the bottom of the box a few inches from the floor with legs, similar to what you'd see in a home sub enclosure.  You could also try facing the sub back and the port firing up towards the rear deck.

Of course (IMHO), the ideal box would have the vent or port facing the back just like the sub, so you might want to build a new box.  I've just given you a suggestion to try out and see if there's a diference, I don't think you'd want to keep it that way.

I'd probably say your better off building a new box, but this time you may want to get some box building software or learn some more about designing boxes.  Building a ported/vented box is much harder than a sealed box and you need to be rather precise about it also.  Good luck. 

thats the solution I was leaning toward.  The boxs volume and port should be perfect, I just have a bad firing direction.

I am gonna have to build a new box, because laying the box on its side to face the sub backward makes it too tall to fit in the trunk.  I am probably gonna have to build a trapezoidal box because at the rear seat bulkhead the trunk is only about 12 inches tall, where the trunk lid begins it is 15.5 inches tall.  ...and of course the existing box would be 16.5 inches tall with the sub facing backward.

thats another thing I was considering, and that question was included in my original email to dbDrive last week, but like I said they never emailed me so I figured it would be better to err in the larger direction, because that would lower my tuning frequency instead of raise it.  But I guess you live and learn, this is my first ported box, and its not like making another box is gonna kill me, just cost me another Saturday and a couple more bucks worth of MDF.

Hopefully this time db Drive will reply to my email instead of just ignoring me, and let me know whether their figure includes the woofer size, and who knows I suppose it could include the port as well.  For those of you who rate customer service as a high priority when purchasing car audio, I would not recommend db Drive.  I do not appreciate being ignored.

ok well heres an update.  I had enough scrap wood laying around to equal about .28 cu ft, which is how much too big my box is if db Drives specs include woofer and port displacement.  I figured it was worth a try as a last resort as I'm prolly gonna have to build another box anyway. 

So I got some jb weld and epoxied the s.o.b.s onto the floor of the box, and cut a new PVC port since I was decreasing the box volume enough to raise the tuning frequency to 45Hz. 

And it sounds the same.  So I'm designing a new box with the speaker and port facing the rear of the vehicle.  Anybody have any suggestions before I start?

I need to get out the tape measure and measure the second box, a friend of mine let me borrow it, I have no idea what its specs are.  Its sitting here in front of me but I have no tape measure here at my apartment.

IMO, alot of ported boxes do sound like garbage, but alot of that is because people just go out and buy a woofer, and go out and buy a box and pay no mind to what kind of box the woofer is designed for or what kind of woofer the box is designed for.  When the box is done right, a ported box can sound almost as good as a sealed one.  I've had this same woofer in both a sealed and ported box before, and it was amazing in the ported one, the sealed one sounded decent but wasn't loud enough to keep up with my highs.

The one I'm using right now sounds like garbage, because apparently the manufacturer doesn't know sh*t about their own product.  Unfortunate, but I guess it means I'll just have to do the calculations myself.  Not like its real hard, I'm not 3/4 through an engineering degree for nothing.

thats actually identical to the box I tried that sounded wonderful, and I've had it in that box before in a 300ZX but I bought this BMW and the box is too tall to fit in the trunk.  

ok I've got another update.  I got some polyfil and put it in the box.  It made no noticeable change in the offensive sound.

I've designed a new box with the sub facing the back of the car, I'll probably build it tomorrow.

ok - another update.

I built another box, exactly 2 cubes including port and woofer displacement, woofer facing the rear of the car, the 4" port facing the side, tuned to 35Hz, filled with polyfil and it sounds GREAT!  The offending sound is totally gone.  The only variable I changed is the orientation of the woofer and i tell ya it made a world of a difference.

Now I've got a nasty rattle in the rear deck to tend to, thats gonna be fun.