2 x 12" Dcon d4 ported box

[BigGuy 22]

I finally took the time out to measure my trunk for a box for my brand new still in the box 2 x 12" Dcon d4 subwoofers. This is going in a 1983 Cutlass Supreme. Height: 14.75" Width: 38" Depth: 21 &1/2". I have no idea how those measurements would convert into cubic feet for the subs. Will a box built to these specs work with these subs? Amp is a Rockford Fosgate 1051s rated at 1100 watts bridged. I jumped the gun and ordered subs before measuring. I realize the trunk is wide but not tall, so box height would be limited, which makes for a somewhat smaller box. Probably should have gone with 10"s. But I'll try to work with what I got. I know in terms of sound I am looking for a balance between "sq/spl", the most musicality. All music gets played. Thanks in adavance for being patient with a learner.

[lithium 358]

you need to figure out what size box you can actually fit into the trunk through the opening or through the back seat.

if you good with a measuring tape try figuring it out that way. another idea would be to make a mock box using card board boxes.

[BigGuy 22]

Unfortunately there is a brace right behind the back seat and the opening would not allow for a sub box of any size. I measured as if the subs were to be facing the rear of the trunk, back of box facing passenger area. I will see if I can get some pics. I'm sure they will help.

[Aaron Clinton 2,372]

If you can, add dimensions with MS Paint or similar program, with the dimensions you have. This will help others to give you an idea on space available.

[porkchop 304]

okay....i hate this lap top....i got help for you but my clipboard is messed up again....no copy and paste happening here.

go to rf box wizard to learn to model up air space easily....

rockfordfostgate.com / woofer box wizard.

your current max dimension specs offer 5.5 cubes for your subs.

you need to subtract port and sub displacement as well.

double baffles and internal bracing as well as 45' degree angles can change the volume as well.

your dcons need 4.5 cubes and displace about .25 cube of your internal volume.

your port would stand 13.25" tall and 4.5"wide would give you about 60" of port area.

personally when the box is enclosed in the trunk i raise the tunning some....this is a preferance....imo, 30hz. would be nice.

i suggest if possible to mod the rear deck in a fashion that will help "port" the bass into the cabin.

many folks find with a stronger front stage that the rear stage is not needed, if you choose thise path your 4"x10" openings being open would help out a bunch.

for a drop in box.the space you have, the port and subs will work out fine and some 45's will be nice. the double baffle is not needed imo. some .75" dowells for vertical and horizontal bracing from your local hardware store will serve as a nice bracing system and cost effective.

[BigGuy 22]

Thanks Chop, you're the man. I have to tell you I was a little afraid it wouldn't fit. Every other box I have had was pre-fabbed, sealed, and they were tiny. I hate how the our Cutlass trunks are made. Looks big from the outside, but it is rather small. I'm still impressed how you're fitting all that gear in your ride. That's a whole other level for sure. I'm still crawling over here. Anyway, I appreciate the heads up about that RF program. I'm going to check it out as I do want to learn how to make boxes. I wish I could hear your as I still have my inner bass head addiction.

[CTAudio 0]

4.5 cubes net is too big IMHO for 2 12" DCONS. I think you will find that 3.5 cubes net is just about perfect for your set up.

[BigGuy 22]

CT, why would it be too big? SSA recommends 2.25 for one so using my logic, which is poor in most cases, doubling that would be 4.5. Please explain because I really am soaking all this info up. All I know is I want a box that going to give the best balance and a nice flat curve. Help understand??? 3.5 or 4.5 net? And what tune for a trunk car?

[CTAudio 0]

^^^^^The reason it is wrong is that there is no law that states the size and number of subs increase at the same rate. The DCON loves smaller ported enclosures and if I am not mistaken the optimal size for two 12" DCONS ported is around 3.3 cubes. I would also tune it around 30-32hz for a daily system. I am sure someone smarter than me will chime in but those are just my thoughts.

[BigGuy 22]

Let me say first say thanks to Alton, Chop, and CT. You guys have really been helpful. I appreciate it. So the question is, should I do 3.5 cubes or 4.5 cubes at 30 or 33 hz in a trunk car on approximately 1000 watts? Of course with 1k watts, I'll be gentle on the gain and volume controls.

This will be my last question as I will have the box made to whatever specs recommended. I'm just extremely happy knowing that whatever box gets made, I know it will fit.

If money were no object, I would just have both boxes made and listen to which one I like best.

Edited June 14, 2012 by BigGuy

[swift 501]

Split the difference and just do 4cu and dont get caught up in stressing over .5. Once you make a decision and move on it makes life easier, lol

[BigGuy 22]

Absolutely right Swift. The thing I like about sealed boxes is their measurements are more or less exact for a sub. Also, all of my past subs have been JL prowedge boxes and Kicker boxes. I'm new to this raw driver and ported box thing. I was wanting to make sure I have the "perfect" box for my subs and my car.

Here is a link to my whip on cardomain. I'm sure you guys want to see what's going on.

http://www.cardomain.com/ride/3158303/1983-oldsmobile-cutlass-supreme

I won't post anymore until I start my build thread. Promise