dual 12s, ***** am ported box build *PICS*

[Lil Poot 5,000+ posts]

decided to get the ball rolling on this ported box, so i ordered the ports, bought the mdf, finished the plans and got cracking. started building today, thought i'd share a few pics. im planning on having 2 4 inch flared ports firing at the driver and passengers heads, with the 12's at the rear, angled upwards.

just test fitting here, actually wont block my rear glass at all with the hatch shut.

basically all i got done today after i finished the plans. i did 2 of the smaller side pieces, but only attached one.

this gives you an idea of the size of the ports i have to accommodate. 4 inch port my ***, its almost 7" at the widest point of the flare.

this is without the box in. going to see where it sits with it in, then drop the front to match. looks goofy all high like this, i know.

Click to read more...

 

[spitfirees20 10+ year member]

Great start, looks like it's going to turn out awesome. Lots of work involved there, but the aero ports are lookin sweet //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif

 

[SAG3 5,000+ posts]

looks complicated

 

[Lil Poot 5,000+ posts]

just a thought, does anyone think i may be able to work in a slot port at the top?

i noticed while reading the instructions that came with the aeroports it said to have at least the diameter of the port between the port and any inside walls, but a 14 inch tall box isnt really an option for me. now, the front section for the ports is 8 inches tall, just enough to fit the aeroports.

 

[IamDeMan 5,000+ posts]

Great project. I think you may want at least 3X 4" ports though. I used 1 4" aero port for my brahma 12" and when it's cranked it makes port noise. Mines in a trunk though so it wasn't as critical, but with those ports getting aimed at you, you're gonna here it. Keep us updated mang.

 

[negativezeroz 5,000+ posts]

just a thought, does anyone think i may be able to work in a slot port at the top?
i noticed while reading the instructions that came with the aeroports it said to have at least the diameter of the port between the port and any inside walls, but a 14 inch tall box isnt really an option for me. now, the front section for the ports is 8 inches tall, just enough to fit the aeroports.

Slot port will most likely take up more cf so it will change your enclosure volume and tuning compared to the aeroports.

 

[PowerNaudio 10+ year member]

i agree with going with at least 3 to 4 4" ports. the only problem is you're going to have to go with longer ports to keep the same tuning.

i suggest you do any part of the enclosure that is not going to be seen like the floor to save you on the weight side.

that box looks like is going to be heavy.

 

[Lil Poot 5,000+ posts]

does anyone have any tricks of the trade for making angled cuts like im going to have to do? when i did the one in my sealed box i just carefully measured the angle and angled the blade on my table saw, but theres got to be a better way to attach pieces at an angle.

yeah i can't really go any longer on the ports, right now they're at the length they came as, i think 18 inches, and they'll just barely fit in there like that. i want to get the thing built first before i cut them so i can have the exact volume in case i have to change anything along the way, but i think they'll need to be about 14-15 inches long each.

i guarantee its gonna be heavy, my sealed box even needs 2 people to remove, over 100 lbs with the woofers in.

what do you mean you suggest i "do" any part of the box that won't be seen?

 

[saywhat? 5,000+ posts]

thats how its done man, table saw adjusted to angle.

 

[PowerNaudio 10+ year member]

what do you mean you suggest i "do" any part of the box that won't be seen?

lol my bad i meant to put in there the word fiberglass. lol

 

[PowerNaudio 10+ year member]

oh and for the angles place a piece of paper on the board and trace the angle, cut the drawing of the angle and place it on the table saw and angle the blade to match the drawing.

 

[baseballer1100 5,000+ posts]

Looks good so far. Keep it up!

 

[Lil Poot 5,000+ posts]

ok i just figured up the airspace, and it looks like im working with 4.97 cubic ft, gross. after .36 woofer displacement and .26 for the ports, i've got 4.35 net.

this is a bit on the large side for a pair of rl-p 12's right? i'm planning on adding a bit of mdf bracing in the middle of each section but i doubt it'll displace more than 1/10th of a cubic ft, if that.

leaving the ports the way they are, dual 4 inchers at 18 inches each will give me about a 28 hz tune right?

 

[IamDeMan 5,000+ posts]

ok i just figured up the airspace, and it looks like im working with 4.97 cubic ft, gross. after .36 woofer displacement and .26 for the ports, i've got 4.35 net.
this is a bit on the large side for a pair of rl-p 12's right? i'm planning on adding a bit of mdf bracing in the middle of each section but i doubt it'll displace more than 1/10th of a cubic ft, if that.

leaving the ports the way they are, dual 4 inchers at 18 inches each will give me about a 28 hz tune right?

Yes. 28hzish is right. The only problem is that when plotted in WinISD, it shows that when these woofs are given full power you will get a port velocity of 17m/s and rising up steeply at 40hz and below. At 25hz the velocity is 85m/s! That is a lot of noise to direct right at your ear.

 

[ngsm13 5,000+ posts]

Tits.

Should be able to fit one more 4" port in there... they don't displace that much... that is... if you have the depth...

nG