buiding a box for 3 sq hds3's in my 2010 cobalt

[skippy90210 10+ year member]

im building a box for my cobalt to fit 3 hdc3 12's

my question is, is 8cu ft of airspace BEFORE ANY displacements too much?

each on takes .78cu ft so the subs will take 2.34cu ft up in the box leaving it with just under 6cu ft after the subs are in is this enough or too much?

also im going with aero ports and was wondering if i should get 1 6 inch port or 2 4 inch port

i want to tune around 32hz and main goal is to hit the lows as hard as possible and to get loud.

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[NASTY08IMPALA 5,000+ posts]

9

im building a box for my cobalt to fit 3 hdc3 12's
my question is, is 8cu ft of airspace BEFORE ANY displacements too much?

each on takes .78cu ft so the subs will take 2.34cu ft up in the box leaving it with just under 6cu ft after the subs are in is this enough or too much?

also im going with aero ports and was wondering if i should get 1 6 inch port or 2 4 inch port

i want to tune around 32hz and main goal is to hit the lows as hard as possible and to get loud.

1 6" or 2 4" aeros are not enough for 3 hds. The sq subs like to breathe..they like bigger boxes with more port area ...id do 2 6"..and will that be cubes after sub and port?? If so thats about as small as id go...ive had all my aq pair of 12s in 5 cubes...and with a goal to hit lows u need port area and box volume...more air flow will have more pronounced low end impact ..bc of the amount of air moved at lower frequencies

 

[skippy90210 10+ year member]

9
1 6" or 2 4" aeros are not enough for 3 hds. The sq subs like to breathe..they like bigger boxes with more port area ...id do 2 6"..and will that be cubes after sub and port?? If so thats about as small as id go...ive had all my aq pair of 12s in 5 cubes...and with a goal to hit lows u need port area and box volume...more air flow will have more pronounced low end impact ..bc of the amount of air moved at lower frequencies

well i can do whatever i need to with the aero ports if 2 6'' is what i need that will be fine, but the box will be 8.29cubes without subs and ports each sub takes .78 so thats 2.34 cubes so 8.29 - 2.34 = 5.95 cubes after sub displacement

 

[NASTY08IMPALA 5,000+ posts]

well i can do whatever i need to with the aero ports if 2 6'' is what i need that will be fine, but the box will be 8.29cubes without subs and ports each sub takes .78 so thats 2.34 cubes so 8.29 - 2.34 = 5.95 cubes after sub displacement

Idk how much 2 6" aeros would displace but that box will probably be on the smaller side for 3 12s...cant go any bigger?

 

[skippy90210 10+ year member]

thats my whole trunk lol because i need a box i can remove

 

[bmk6795 10+ year member]

those subs don't have a displacement of .78 cubes.. more k

like .16ish. if you are using aero Ports that box will be fine, should be a bit bigger than 6 cubes.

 

[NASTY08IMPALA 5,000+ posts]

those subs don't have a displacement of .78 cubes.. more klike .16ish. if you are using aero Ports that box will be fine, should be a bit bigger than 6 cubes.

I thought he meant .78 for all 3 lol

 

[NASTY08IMPALA 5,000+ posts]

thats my whole trunk lol because i need a box i can remove

Yea the disp on those subs isnt .78 each ...my hdc4 12 are only .26 and they weight 70lbs each...that box will work fin e with 2 6" aeros

 

[skippy90210 10+ year member]

Yea the disp on those subs isnt .78 each ...my hdc4 12 are only .26 and they weight 70lbs each...that box will work fin e with 2 6" aeros

so is the displacement less then .78 per sub? i thought thats what the site said but i could be wrong haha well if this box will work i want to start building it haha

 

[bmk6795 10+ year member]

I thought he meant .78 for all 3 lol

i did at first then saw he was taking 2. something cubes for sub displacement, lol.

 

[NASTY08IMPALA 5,000+ posts]

so is the displacement less then .78 per sub? i thought thats what the site said but i could be wrong haha well if this box will work i want to start building it haha

No id bet that its like .12-.17 each buy some aeros and start building

 

[skippy90210 10+ year member]

okay cool i just wanted to make sure the box will work before buying and wasting wood haha also i should mention i will be putting the ports through the rear deck of my car so it fires off the rear window and i wont have to have my seats down so basicly is it okay to have the ports extend out of the box some?

 

[NASTY08IMPALA 5,000+ posts]

okay cool i just wanted to make sure the box will work before buying and wasting wood haha also i should mention i will be putting the ports through the rear deck of my car so it fires off the rear window and i wont have to have my seats down so basicly is it okay to have the ports extend out of the box some?

Yes u can def have the ports out of the box ..are u gona cut holes in the rear deck? What kinda wood are u using?

 

[skippy90210 10+ year member]

Yes u can def have the ports out of the box ..are u gona cut holes in the rear deck? What kinda wood are u using?

yeah i was gonna cut holes in the rear deck, is that not a good thing to do? and im gonna use mdf

 

[NASTY08IMPALA 5,000+ posts]

yeah i was gonna cut holes in the rear deck, is that not a good thing to do? and im gonna use mdf

No its fine..id use arauco birch or maple ..mdf is so heavy and pourus and splits easy ..save some weight