Building a box for a Fi Q12. Any input?

[REVOofRustler]

Hey guys! This is my first time building a box and I think I have it figured it out, but I still have a few questions. The box is going in the back seat of my extended cab Dodge Dakota, so I don't really have a ton of room to work with. I'm trying to keep one seat in the back open so I can fit two other people in my truck.

Anyways, here's what I've done with the box calculator:

For the calculator, do I need to find out the displacement of my port walls? Or does it factor that in by itself? The displacement I have plugged in there is just from the 45's.

Here's what I've been able to come up with in Sketchup:

The box will be pushed as far towards the passenger side as possible with the port basically pointing between the passenger seat and the door.

I was wondering though, would it be ok to "cut out" the corner of the box like this?

That corner would be up against the back rest and the side of the cab. If doing the corner on the box like that is ok, it would help with getting it to sit further back in the seat.

Also, does it matter where the sub is placed on the baffle?

For example:

Placed close to the port

vs.

Placed away from the port

vs. centered like in the first picture of the box.

For now I'm stuck with a 12" Type R, but I'll be ordering a Crescendo BC2000D when I get back from vacation in a couple weeks.

As for options on the Q12, I'll be getting the cooling package, the extra spider, and I'm wondering if getting the internal leads is worth the extra $25 bucks. I've read on here that it will eliminate lead slap, but I've never actually heard a system with lead slap.

I'll be running the Q12 at 1 ohm, and I'll keep the gain down a bit so it's not quite getting the whole 2250 rms.

Here's a few pictures to show you how much space I have to work with:

This is the prefab box I have now, and I believe it's about 18 inches wide and 15 inches deep at deepest part.

Anyways, I'm trying to get this done right the first time, so any help is appreciated! Thanks!

[Joe X]

Torres takes care of the non common port wall displacement, that's why you need to set a common walls number.

[REVOofRustler]

Torres takes care of the non common port wall displacement, that's why you need to set a common walls number.

Awesome! Thanks for the input!

[REVOofRustler]

Can anyone give advice on cutting the corner like that? I wanna make sure the box fits well in my truck, but if I lose too much strength in the box because of it, I'll just toss that idea out.

[HunterJohnson]

If you do lose strength just resin and mat the back

[Miguels]

i would say screw the passengers and wall it. get an SUV for passengers have you considered making a blow through?

[REVOofRustler]

I would if I could! Haha. I ride dirtbikes and mountain bikes, so I need to be able to have a bed to put all my toys in. Im also workin a minimum wage job so buying another car really isnt an option for me. It would definitely be fun though!

Edited July 1, 2012 by REVOofRustler

[REVOofRustler]

I've got another question about Torres that's probably really stupid, but whatever.

I looked in the "Help" menu of the calculator and it says,

"Port length uses the box wall or baffle(s) as part of the port length. So a port that is 10" long with one baffle using .75"

wood will only need to be 9.25" long as the box wall or baffle(s) will account for the other .75". If using two baffles,

then it would be 8.5" long as the baffle will account for 1.5" of port length."

So does this mean that my port length of 32 inches would start after the second baffle (Which would give it an actual port length of 33.5 inches since I'm using a double baffle)?

It can only really make a difference of like .5 hertz so it's not a huge issue, but it would just be nice to know how Torres is measuring the port length.

[mttornquist]

No that means that it includes the thickness of the baffle in the length of the port. That just means that the port starts at the very front of your box rather than behind the baffle. the centerline length of your port should be 32 inches from the inside end of your port to the very front of the box.

If its 32 inches down the center to the outside edge of your baffle you did it right.

Not sure if that makes sense, kinda hard to explain.

[REVOofRustler]

Ohhhhhhh I see what it's saying now! Thanks!

Here's another question though... At the bottom of the calculator it shows the actual equation it's using. However, it's using a port length of 33 inches in the equation when I've only inputted 32 inches into the calculator. Where is that extra inch in the equation coming from?

Sorry for all the questions!