Need pro help, spl subs to fit in specific space

[Jduane]

I have a f350 dually quad cab with the equipment seen below.

Good alt. big 4, 3 batts,

I moved the back seats up and forward to get more room. I have 5.5 cu.ft. Behind the rear seats for subs, that includes box and displacement, for 2-4 subs

I'm looking at soundqubed hc3 12's or sa 12's what's you opinion on subs and box configuration?

Needs to be wedge shape box bottom depth is 13" top is 4" height is 23" length is 61"

Click to read more...

 

[blazian87 10+ year member]

I think 2 HC3 12's would work well in that application. You can do either a slot ported facing forward or if you want a little more spl use a 6" flared aero facing forward, which might have to be external for it to work.

 

[Jduane]

External port is a great idea thanks

Any recommendations for a box size with external porting, I don't have any software to test and did a lot of searching with different results

 

[blazian87 10+ year member]

External port is a great idea thanks Any recommendations for a box size with external porting, I don't have any software to test and did a lot of searching with different results

If you only have about 5.5 cu ft to work with then basically as much as that as you can squeeze in. The more the better. The HDS3 likes big boxes that's why. External porting is much easier to calculate. You just design a sealed box essentially and just add however much port you need for tuning. Make sure to account for bracing if you decide to use any. I would suggest a double baffle for the subwoofer side if you can fit it.

Use this calculator to figure it out. Products Menu

With 5.5 cu ft net volume, it'll be roughly 10" long for 32 hz tune and 12" long for a 30 hz tune. Look at flared length, not straight.

Here's the port I'm talking about. Precision port makes it.

Precision Port 6" Flared Port Tube Kit

You can also use the calculators from here for the wedge box. Scroll down for it.

Subwoofer Enclosure Calculators, Parallel, Series, Port Length and Volume

If you can go without the wedge box though, you can get more airspace easily.

 

[mylows10 5,000+ posts]

Ok first off the box calc that's given sux. Bad. Don't use it. Also. Port the box off the side wall you'll get better results there's a few box designers here that can make a design for you. For a price tho. I suggest talking to one of them

 

[blazian87 10+ year member]

Ok first off the box calc that's given sux. Bad. Don't use it. Also. Port the box off the side wall you'll get better results there's a few box designers here that can make a design for you. For a price tho. I suggest talking to one of them

What's wrong with the calculators provided? I don't understand. Is it inaccurate or just hard to work with? I used the Precision port calculator for tuning my aeroport box and it worked just fine. I even did the math equation on paper and got the same exact answer. Are you referring to the wedge calculator?

 

[blazian87 10+ year member]

OP Here's another nice tuning calculator that is very useful. https://www.mediafire.com/?rwlf754d3th1f56

 

[mylows10 5,000+ posts]

The box calculator isn't very good. The psp port calc. Should be fine if you have internal volume

 

[blazian87 10+ year member]

The box calculator isn't very good. The psp port calc. Should be fine if you have internal volume

Yea never worked with wedges before. I realized this calculator doesn't even let you do the top depth so it's flawed. Thanks for the tip.

 

[blazian87 10+ year member]

Enclosure Volume Calculator - Subwoofer Box Calculator

I think this wedge calculator should be sufficient..

 

[blazian87 10+ year member]

OP I just calculated with the specs listed above W 61 H 23 D1 4 D2 13 and it appears to be 5.182 cu ft with .75 thick wood. That's before sub and port displacement. Might have to play around with port ideas but it should be enough for those 2 12's.