Help designing a box: port area / tuning?

[LinxuS 10+ year member]

I was thinking about doing this box, maybe tuned to 35 hz.

With that box only, without port / sub displacement, it comes out to be 2.75 cubes just about.

Could anyone help me design a box with a port? Was thinking maybe having the port come out the top, or flattening the bottom of the front angled piece, and putting the port down there. This is going in a Ford Ranger extended cab behind the drivers seat. Probably going to be holding a FI Q.

Aero Ports or a regular port is fine, just anything that could get the job done.

BOX: 18" Base, 21" High, 18" Bottom Depth, 12" Top Depth.

If it would help a whole lot, or if im in dire lack of air space, and need more I could do this: On the bottom of the box, drop it down 4" in front, and about 12" back. So basically another box on the bottom with dimensions of 18" Base, 4" Height, "12 depth. If that few little cubes will help out a lot I could probably work with it, but it'd make the box building on my part quite a bit harder.

Any help is appreciated.

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[Big Dee 10+ year member]

That space is fine for a 12" Q.

A 5" round port 13.7" long aimed up would be pretty sweet IMO.

That would give you the 35 Hz tuning.

I got 2.44 cu ft after displacement if your NET volume calculation was right.

 

[LinxuS 10+ year member]

Just a single 5" port, 13.7 inches long would be enough? Would it give me any problems as far as port noise?

And my other worry was if the tuning is too low? Should I go higher, or maybe even lower? I definitely want more SPL than SQ from this sub, even though it's mostly a SQ sub. Music type is mainly rap.

 

[LinxuS 10+ year member]

And where can I buy a 5" port from? Parts express only had ones going up to 4".

 

[Big Dee 10+ year member]

Well you can't fit 2 4" ports unless you build that little box on the bottom, or use a slot port, or raise the tuning.

 

[Big Dee 10+ year member]

And where can I buy a 5" port from? Parts express only had ones going up to 4".

PVC pipe my friend, hardware store.

 

[LinxuS 10+ year member]

Ah, so i'd be okay just doing that instead of flared?

EDIT: looking through and saw that some people made them flared themselves.. how do I go about doing that? Does it involve molding or anything?

 

[LinxuS 10+ year member]

I've decided to go with about 30-32 hz instead..

For a 2.5 cubes box to 30 hz, i'm assuming a single 4" diameter, 13.3 inches long port isn't going to cut it..

Any other ways around this?

 

[PowerNaudio 10+ year member]

I've decided to go with about 30-32 hz instead..
For a 2.5 cubes box to 30 hz, i'm assuming a single 4" diameter, 13.3 inches long port isn't going to cut it..

Any other ways around this?

i think you will get allot of port noise out of a single 4" port. it would be best to just go sealed.

specialy having the sub so close to you. you will be hearing port noise from like 40Hz and below. if you play music that stays away from those freqs then go with the single 4" port. if not. then go dual 4" ports or go sealed. it would still sound very good and hit very low in a sealed enclosure.