Help with a ported box design for 2 Kicker CVR 12s

[MrDrRoscoe]

There's probably been about 50,000 CVR 12 boxes built but I can't find one that will fit in my G6's trunk that actually gives any specs. This is my first box by the way.

I can have a max of 4.5ft^3 with two of these, each sub uses a recommended 2.25ft^3 which includes sub displacement.

My max dimensions are 14in height, 36in width, and depth doesn't matter much but probably 24in or less.

I'll probably do a flush mount just to make it look a little nicer.

I'm not sure about what to tune the port too or the length, 32Hz sounds like a nice number to me if I can fit it. Every calculator I use seems to give different numbers.

If anyone can help me design a box I'd be grateful. I've been working on one in SketchUp I'm really just not sure if I'm doing things right.

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[Better-Action 10+ year member]

How much power you giving them. I had 2 12 cvrs in a 4cf tuned to 34hz and it did nicely. Build a box and as long as its withing 4-4.5cf 32-38hz tuning and at least 10" of port per cube and you'll do alright.

 

[MrDrRoscoe]

I'm using this amp, the voice coils are in series and the subs are parallel so the load is 2 ohm

 

[disturbed471985 5,000+ posts]

I'm using this amp, the voice coils are in series and the subs are parallel so the load is 2 ohm

There ya go buddy..... Also, that amp is just fine for them..

Enclosure Specifications:

Fb = 37,503 Hz

Vb = 4,5 ft^3

Subwoofer Mounting = Flush Mounted

External Height = 14 in

External Width = 33 in

External Depth = 25 in

Port Width = 4 1/2 in

Cut List:

* All Dimensions in Inches.

* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

Front = 27 3/4 x 12 1/2

Front Internal = 27 x 12 1/2

Back = 33 x 12 1/2

Left & Right Sides:

Side 1 = 23 1/2 x 12 1/2

Side 2 = 22 3/4 x 12 1/2

Top & Bottom = 33 x 25

L Port Internal Assembly Parts:

Front to Back = 14 3/4 x 12 1/2

 

[MrDrRoscoe]

There ya go buddy..... Also, that amp is just fine for them..
Enclosure Specifications:

Fb = 37,503 Hz

Vb = 4,5 ft^3

Is Fb the tuning frequency?

I had to alter your design a little. The front baffle needs to be 14in high because cutout is 12.625in in diameter, the internal cutout is 11in in diameter so its fine. Also one of the sides was a little short and I had to change the depth of the top and bottom pieces because of the baffle.

Here are my edits, the weird decimals should be 24.25 and 23.5 when I actually cut them.

 

[disturbed471985 5,000+ posts]

Is Fb the tuning frequency?I had to alter your design a little. The front baffle needs to be 14in high because cutout is 12.625in in diameter, the internal cutout is 11in in diameter so its fine. Also one of the sides was a little short and I had to change the depth of the top and bottom pieces because of the baffle.

Here are my edits, the weird decimals should be 24.25 and 23.5 when I actually cut them.

Yes to the FB question.. Took a glance at changes an I think all is good

. Measure twice... ***** to build a box just to have to toss..

 

[MrDrRoscoe]

Yes to the FB question.. Took a glance at changes an I think all is good. Measure twice... ***** to build a box just to have to toss..

I figured it would all be fine since I didn't change any internal dimensions. I already exploded the box and made sure I can get it all on to one sheet of MDF.

Rounding off the inside port wall and the opening won't affect anything really will it? I may put in a 45 degree in the port also if I can cut it.

Thanks for the help, you solved my problem and then some!

 

[disturbed471985 5,000+ posts]

I have always used 45's in all corners. So I say use them can't hurt. One sheet mdf hmmmmm not sure. I only use birch and if going that route one sheet want make it.. Few years back got tired of replacing shocks every 6-8months. Best audio decession to date.

 

[MrDrRoscoe]

I might just go ahead and cut 4 45s then for each corner, I might only be able to fit 3 since the there's not a ton of room between subs but that's fine. I put all the pieces beside eachother in SketchUp to see if they'd all fit on a 97x49in sheet of MDF, then I found this optimal cutting calculator which seems to work really well, and it's free.

I don't know how much this bastard will weigh but hopefully it's not too bad on anything.

 

[disturbed471985 5,000+ posts]

I might just go ahead and cut 4 45s then for each corner, I might only be able to fit 3 since the there's not a ton of room between subs but that's fine. I put all the pieces beside eachother in SketchUp to see if they'd all fit on a 97x49in sheet of MDF, then I found this optimal cutting calculator which seems to work really well, and it's free.I don't know how much this bastard will weigh but hopefully it's not too bad on anything.

Always room to somehow get something on the corners to eliminate those dead spots an get that air flowing smoothly. 1 sheet 3/4mdf plus glue, screws min of 100lbs. Now toss in subs, wiring, amps, and I hope at least a set of batts ur in the 3-400lb range.. That's a lot of weight no matter which way u look at. If my current box was mdf it would weigh a solid 150lbs but by using birch I'm right around 100lbs only draw is price of birch bout double if not more then mdf. Just depends where u live.

 

[MrDrRoscoe]

After doing some more thinking and modeling, there's basically no way to fit a box that size in to my trunk without building it inside of it. So I might do two 2.25ft^3 boxes and just have to live with that for now. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif