Help Needed - Fi-nally Box Build... SP4 v2+ 15 on DC2ks

[Joshdashef]

It has been a very long time coming. Finally getting around to pull everything out and start building again. Threw my back out after a long month of staying in the hospital and long road trips, so make sure you guys are stretching and doing some core! Took me a week to recover but now I am about 90% back and ready to go. 

 

Amps: Two DC 2ks strapped ~ 4k

Goal Volume: 3.5 - 4

Tune: 30 Hz

 

This time I will be doing some things different, including the box. Single 15" Fi SP4 v2+ 15 (link)

Options: Dual 1 ohm | 7" Gloss Carbon | Hybrid leads | 4 spider | Cooling = Yes | 4" Voice coil

 

Max dimensions are as follows: Height - 16" | Width - 34" | Depth - 17" | Wood Thickness 0.75 MDF

Height and Width are pretty much as much as I can squeeze, but I can play around with the depth a little bit up to around 18/19

Some sub specs:

overall diameter = 15.625”

cutout diameter = 14.125”

mounting depth = 11.00”

subwoofer displacement = 0.21 cubic feet 

 

With these current measurements, not including displacements for port/port walls/subwoofer/etc, inner dimensions are H 14.5 x W 32.5 x D 14.75 = roughly 4.0225 cubes internally

Here is a sketchup rough draft of what I am planning so far. Double baffle, playing with the possibility of aero ports instead of a slot port. Also will be doing some cylindrical bracing inside the box, not sure what material yet but likely wooden dowels about 1.5-3 inches thick in diameter going back to front and top to bottom. 

 

Wanting to achieve at least 60" squared port area, going off minimum of Triticum's Improved Port Area Calculator

 

 

All in all I am looking at least 0.21 for the sub, around 0.06 for bracing cylinders, might need 45s, and the volume taken up by the port...

That leaves me around 3.7 ish net volume

 

Played around with the idea of two 6 inch ports for about 56.5 port area. However when I put it in WinISD It shows I need a total length of ~37.7" for a 4 cubes box tuned to 30

 

 

Any input would be appreciated. 

Here is some pictures of my trunk for reference, it has a false floor of cardboard not even half an inch thick. 

 

 

[CstrokerV]

Just an f.y.i the displacement of those 2 ports is 1.24 cubesYou don’t  have enough space for that sub with those dimensions,  And that’s without brace displacement, from  your calculations you have close to  a 3 cubes box after sub and port displacement which will tune the box different then your calculations.  With what you want you need a box with an internal volume around 5 cubes

[Joshdashef]

40 minutes ago, CstrokerV said:

Just an f.y.i the displacement of those 2 ports is 1.24 cubesYou don’t  have enough space for that sub with those dimensions,  And that’s without brace displacement, from  your calculations you have close to  a 3 cubes box after sub and port displacement which will tune the box different then your calculations.  With what you want you need a box with an internal volume around 5 cubes

Thanks for the heads up. Looks like I need to re think my original layout plan. 

 

If I did go for an aero port, and it extended outside of the box, I would treat it the same essentially right? It just wouldn't cause as much displacement inside of the box

[CstrokerV]

Yes you subtract the part outside the box... 

[Joshdashef]

redesigned the box. Came to 4.124066 internal volume after factoring in displacement for a 14.5 by 4.25 port by 39.46 long. After taking away .21 for the subwoofer and .2-.3 for bracing I should be left with around 3.7 internal net. 3.5 likely if I add some 45s

 

This is a barebones sketchup, no 45s or bracing yet. But how does this look? Black outer circle is overall diameter

 

I'll end up with about 61" squared of port area. Appreciate any input you might have @Triticum Agricolam

 

[Joshdashef]

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