View Full Version : 5 cubes GROSS for 2 12" HDC3s

04-28-2008, 04:51 PM
I'm gonna be ordering this setup either tonight or tomorrow so let me know now before i make a mistake on this-

I have 5 cubes gross for 2 of these subs.

After sub and port displacement, i have 3.75 cubes NET

Is this gonna be enough for these subs?

I was talkin to DJ about it earlier on the phone and he was kinda iffy about it but the kicker is that i am running 2 AQ2200ds to this pair so I do not know if it's advisable to keep them in a box like this due to me giving them this extra power...

What you guys think?

Think i should do the 2 12s or something else like 3 RE SX 10s in 3.75 cubes NET? Can they handle 1,500w per? or are these 2 12s gonna be potentially louder?

Tuning for the AQ 12s is gonna be at 40hz, if i went with REs subs it would be at 35hz.

I was thinkin about 3 ICONs but i have too much power

I was also thinkin about Fi BLs but i think RE SXs may be louder.

Let me know guys, Thanks.

04-28-2008, 05:07 PM
is 3.75 all you have? Whats your vehicle?

i have mine in 5.5 cubes NET and they sound pretty good. I have about 5kw on tap and its a little more than they like in that box.. But running them in a smaller box should help their power handling.

04-28-2008, 05:12 PM
i have already cut all the pieces for the box.

It's for a 2007 scion tc.

I had to leave room for 2 AQ2200ds, 1 sundown 100.4 and 3 Kinetik HC1400s, extra internal sirens and enough air room for the side firing port to travel back which is an extra 4" of width from box to wall.

And..., hehe, i wanted to leave enough "see-through room" so i can still use my back window.

It's 5 cubes gross exactly. Port takes up 0.9 cubes. 2 subs= 0.4 cubes displaced.

I know it'll get loud 40hz and up for sure, but i am just afraid a box like that.... not saying it will, but am afraid anything let's say 35hz and under is gonna be almost completely silent.... Any thoughts on that?

04-28-2008, 05:33 PM
i'm not really sure. I know mine gets down fairly decent. I'm tuned to 38.. it starts to noticably roll off in the low 30's. They like bigger box's to get low, but your smaller cabin will help on getting down too.
I drive an explorer, so i have a good bit more air space to fill than you.

You should be fine tuned to 40.

04-28-2008, 05:54 PM
well, with me side firing this port, crossing my fingers that acoustic length continues as it exists the port more than normal...

Reason why i say that is because every direction but up is walled off around the port exit.
The only direction air can go is toward me and up only an inch...

Hopefully the little 4" wide tunnel that's left beside the box adds to the acoustical length a little to get the lows back in action.

04-28-2008, 06:08 PM
the website recomends 2.5 cube feet PER 12 inch hd3 including displacement of subs ,

SO double that for 2, and GROSS you need 5 cubes

04-28-2008, 06:11 PM
yea i know, sounds simple dont it?

That's why i thought it was easy.

The site says there's no need to subtract sub or port volume...

that means that 2.5 per 12 is GROSS so having 5 internal GROSS should be perfect!

But when i was talkin on the phone with DJ, i could have swore he said i need 4.6cubes after sub displacement then i need to add port in addition to that.

I may be wrong but i know what u r saying, the site makes it easy.

Everbody elses 12s need 2-2.5 net per sub, that's what makes me worry bout me only given them 1.85 per

bad @SS chevy
04-28-2008, 06:15 PM
You need a 5 cube box, tuned to 40hz, 90-100 sq inches of port.... 5 cubes after port and sub displacement.

04-28-2008, 06:17 PM
well, if that's the case, then this setup won't work obviously.

So new route-

got bout 36hrs to make decision-

3 10" Fi BLs with cooling or 3 10" RE SXs... off of 4,400w of AQ power.

bad @SS chevy
04-28-2008, 06:21 PM
You can definanlty make 2 12''s work in your car though.. My current box is only 4.0 cubes tuned to 35hz, and it rocks everyones socks off. 2000 rms going to each w00fer youll be fine...

king ranch
04-28-2008, 06:24 PM
might want to consider aero's

04-28-2008, 06:24 PM
i dont understand?

If i need more volume, how would my car help with that?

I know i should run subs that fit rather than forcing something that may not work.
I want to make sure that whatever i go with is the best choice of course.

3 10s have full output potential in this type of box.... are you guys still considering 2 of these 12s will outperform 3 of either of those 10s in the 1.3cuft per....

04-28-2008, 06:27 PM
i've already thought about aeros and just regular pvc, don't have room for pvc and would need 2 6" aeros but if the outer flange diameter is larger than 8" which i'm sure it is, then it wont fit either.

04-28-2008, 07:02 PM
aeros? theyre like 8.25or somethin, but man you can cut back on port space with an aero...... i was almost 11-12 gross, b4 i decided to use aeros now im down to a lil less then 8.....its worth a try.......

04-28-2008, 07:14 PM
i would need 2 of them 21.25" long

I just did the math, it's only gonna save me 0.25cuft...

Not that big of a difference.

Honestly, i think i may be better off with 3 10s.. what u guys think?

I would go with HDC3s but weight is also an issue.

wanna stay around 100lbs

So... Fi BLs or RE SXs...?

And... i take it the 2 12 HDC3 idea is history correct?

04-28-2008, 07:29 PM
is your box a common chamber?

04-28-2008, 07:49 PM

It's already built, just no holes cut yet nor port.

17.75" high
36.25" wide
17.75" deep
Double baffle being used, subs forward, port to passenger side.

16.25" high
34.75" wide
15.5" deep
5.06 cubes GROSS
0.2 per sub displaced-
4.66 left
Port displaced - 0.9
3.76 minus allthread displacement... 3.6-3.7

04-28-2008, 07:59 PM
port dimensions?

04-28-2008, 08:07 PM
if i went with AQ,
16.25" high
4." wide
19.25" deep
65 sqin port area
Slotted port tuned right around 40hz.

04-28-2008, 08:11 PM
I have 2 right now in 3.6ish tuned to like 33hz.....with 2 500.1s strapped at 2ohm

Gain is set on low side.....but they sound fine and take some good power

Ima have to meter them in a bit to see

04-28-2008, 08:14 PM
Is that what i'm going to have to do then?

To prevent risk of losing the low end, just tune a lil lower than 40hz?

Let's say 35 at the lowest?

I still own 2 of the original HD3 15s, i have experience with AQ.

it's just, i went crazy with their 15 in the past.
Never ran more than 1, but i did run one of those in 7.9 cubes at 29hz, hehe.

Tore my car apart.

04-28-2008, 08:31 PM
Is that what i'm going to have to do then?

To prevent risk of losing the low end, just tune a lil lower than 40hz?

Let's say 35 at the lowest?

I still own 2 of the original HD3 15s, i have experience with AQ.

it's just, i went crazy with their 15 in the past.
Never ran more than 1, but i did run one of those in 7.9 cubes at 29hz, hehe.

Tore my car apart.

This is what Jeremiah25 has told me

Lower Cu and lower tuning for his best results

I had my 4 in 2cu per at 40hz and it was nuts on the lows as well

But this one seems a tad bit better on lows......it might could be a lil higher but im not cutting the port to tune 2hz higher

good luck

04-28-2008, 08:33 PM
thanks man, u and Jeremiah are the Mans, lol

Guess i'll be order 2 AQ2200ds and 2 HDC312 D2s tomorrow.

Should be one loud hatchback

04-29-2008, 08:56 AM
i plugged your dimensions into my spreadsheets its a 3.84 net tuned to 39.22.

04-29-2008, 09:01 AM
What about 2 HDc3 10s?

04-29-2008, 04:47 PM
i had thought about that...
But i don't know if it's worth it for what all money i am spending already.

I have ran 2 10s before tuned to 40hz off of a 1200w amp...

I just don't know spendin $1,300 on 2 10s and amps is worth it.