SQ help

1996blackmax

I really liked my Arc Audio 12D2, similar to the IDQ and built by Image Dynamics. Only reason I switched was that I wanted more output and power handling.

dolfan87

Ok here is today's progress...and guess what?! Fiberglass!!! Well almost.

First I had to figure the angle of the baffle in the corner of the trunk.



Next I cut the side pieces, and decided to round the top of the box for a very non linear shape. Should provide much better sound quality.




Screwed and glued...



Next I went to Wal-Mart and picked up the 100% polyester felt so I can be cool like Frodo.



I stretched and stapled the felt prior to adding the bracing I wanted along the back and top. Screwed up my nice stretch job, but the back will never be seen, so I am forging on.




Test fit. I am going to run a 1/2" leather covered MDF cover that will completely conceal the box. It will run from the tail panel to the amp rack, and give the sub and grill a recessed look.



My first resin!! I layed it on fairly well, and the felt was soaked but not dripping on the inside of the box.



Tomorrow I will glass it, build the cover, wrap it in leather, and install the box.

Gram

MacLeod

Looks great dude! Youre definitely handy with a jig saw!!

One thing, that box looks awful small. What sub are you using again? Is that a 10"? If so, that box should be at the very least .50 ft3 and preferably .6

If its a 12, that definitely looks too small. I cant tell everything from pictures so correct me if Im wrong but just wanted to make sure you check on that.

dolfan87

It's 14" deep, 11.75 wide, and between 7 to 11.5 high. Should give me .85 c.f., and the IDQ wants .88.

Should be ok yeah? I can always add a bit of batting.

Oh and I used a router for the baffle hole...with a jig, so I am not THAT handy.

Gram

exalted512

those subs work extremely well in very small boxes. You can put a 12 in half a cube...he looks like he has about .6 there so hes in the range of the box that sub needs.

What amp are you running to it and at what ohm load?
-Cody

exalted512

i stand corrected...

dolfan87

Running the 500.1 at 2 ohms.

MacLeod

dolfan87 wrote:

It's 14" deep, 11.75 wide, and between 7 to 11.5 high.

Those are the INTERIOR measurements, right?

Youre obviously not a newb at this so I dont mean offense, but if thats exterior measurements and youre using 3/4" wood then that would only be .57 ft3.

exalted512

With that power, I would keep the box no more than .8 and no polyfill
-Cody

exalted512

MacLeod wrote:

Those are the INTERIOR measurements, right?

Youre obviously not a newb at this so I dont mean offense, but if thats exterior measurements and youre using 3/4" wood then that would only be .57 ft3.

time to bust out the peanuts:D
-Cody

dolfan87

Well Mac, you had me second guessing myself, so I went out and re-measured. You're right, I completely brain farted.

Actual INNER dimensions are (taking the deep average between bottom and top) 8.5 deep x 11.17 high x 12.17 wide.

Crap. CRAP! I haven't built a box in years, and I can't fit any more box in that corner, and actually be able to install it once it's built. I BARELY can slide it past the trunk hinge at the current width, and it can be no more deep or high.

The sub itself is going to eat .07 ft3.

Awe man what a bummer.

exalted512

that leaves you with about .35 after displacement.

If you could get another tenth of a cube and some polyfill, it would still be very doable. Like I said, those subs will work in a box down to .5, so if you can get 0.45 and stuff it, after displacement, the sub will 'see' about .5. And paired with a 500.1, I would say itd be about perfect.
-Cody

dolfan87

my calcs landed the box at .67, minus the sub leaves me .6 flat.

8.5 x 11.17 x 12.17 =1155 right? divided by 1728 = .668??

Did I screw something else up now?

MacLeod

The one thing you need to do is since the top of the box angles down toward the back you have to figure the height different.

Say if the highest point is 12" and the lowest is 10", you add the 2 together and then divide them by 2. 12 + 10 = 22 / 2 = 11. So 11 would be the value you would use for the height.

Actually you would do this for any side that tapers in or out at an angle. I just looked at the pics again and not only does the top taper down at an angle but so does the back so youll have to do that forumal for the back and the top.

dolfan87

ok, re-calc'ing it now.

exalted512

dolfan87 wrote:

my calcs landed the box at .67, minus the sub leaves me .6 flat.

8.5 x 11.17 x 12.17 =1155 right? divided by 1728 = .668??

Did I screw something else up now?

100% correct, i was taking account thickness of the wood still....I thought that box looked about .6

Eitherway, .6 after displacement is not bad for that sub, especially with the amount of power you have at hand
-Cody

exalted512

im still a fan of peanuts...
-Cody

dolfan87

Ok guys, I busted out my wifes flexible tape measure. Grabbed the box, and the inner dimensions are...

Top (depth wise) is 7". Bottom depth is 10.75. The average is 8.875.

Width It's a flat 12" across.

Height Short side is 10.25, high side is 12.5 for an average of 11.375.

Multiplied them all together= 1211.43

Divide that by 1728 and I get .701

Subtract the .07 for the sub= .631

Still kinda small. I am a bit upset right now because I don't know where to gain any more space.

dolfan87

Rebuilding the box today...bleh.

MacLeod

Thats not that small of a box for a 10. Slap some polyfill in there and you should be ok.

I was only able to squeeze out .53 for my box but I used a lot of polyfill and some Dynaxorbs and it works pretty well.

dolfan87

I talked with Image Dynamics today, and I am glad I did. They said that for my particular set up, this smaller box is almost perfect.

Reason is that the IDQ 12" with a .615 (lol...more on how I KNOW the box is exactly .615 later) is a great match is because I am using the 5.25 components (as opposed to the 6.5's for lower midbass) for the front stage. My smaller box raises the ideal tuning freq. on the sub from 15-35 at .88 c.f. to 19-50 hz. My mids (according to them are good to about 80-90) and with roll off it will cross nicely.

So I am going to run it, and see how it goes. Worst case I will have to rebuild the box, but it's looking like I am in good shape for now.

So onto how I know my box is .615. I was fiberglassing the back today, when I decided to resin and glass the corners inside the box. Then I just resined the whole inside. When that dried, I grabbed a gallon jug, filled it with water...my box, level, holds EXACTLY 5 gallons and two cups.

I have some pictures of the glassing coming in after I eat.

exalted512

dolfan87 wrote:

I talked with Image Dynamics today, and I am glad I did. They said that for my particular set up, this smaller box is almost perfect.

did i not say that?
-Cody

1996blackmax

You can also play around with some fiberfill to get a little more low end if you want.

dolfan87

exalted512 wrote:

did i not say that?
-Cody

Cody, brother, you did say that...but it was the explanation that really set my mind at ease. You were right though.

Here is the updates:

Ok, here is the first two layers of chop mat.





I started cutting my pieces, and numbering them to make things quicker. I saw someone else on here do this, and it really helped me.




This was like my fourth layer. After this I ran out of chop mat...and so did ACE hardware. They only had the cloth left in stock, so my final four layers was with the cloth. I didn't take any pictures of the cloth, but it looks about what you would expect. So a total of 8 layers of 3/4 ounce mat and cloth. I also layed some glass inside in all the corners.



Installed the box in the trunk, and then began the cover piece. The sub will sit recessed in the cover, and I have yet to decide if I am going to run the grill. Here is the cover...umm..."covered" in leather (sorry the picture is a tad blurry, but it was way dark by the time I took this shot.)



Ok, that's it for now. Tomorrow will see the sub in, and then I'll begin the passenger side of the trunk with the Alpine H701 processor.

Phew...so how did I do on my first glass?

exalted512

looks fantastic!!!! I wish I could work that fast!!!!! Or at least have the time and a garage to do all that.
-Cody

dolfan87

LOL...car is in the garage, but I work outside because of the dust and resin smell.

dolfan87

Here is the cover...I forgot to add it to the above thread.

ben62670

1 Gallon = .12 cubic Ft. ? I was going to ask earlier if anyone has used water to figure out Sq Ft

Nice work

dolfan87

1 gallon= .133 c.f.

Yeah, if I hadn't of resined the interior of the enclosure, I wouldn't of tried it.

But now I know for certain what I have...even if Cody and Mac guessed just by looking at the pictures. lol

ben62670

Yes MDF does Not like water!
Do you have any pics of the rest of your car. I am a Ford fan from way back. I have a 68 Bronce with 360 horse bracket racing 302 single plenum manifold, double pumper carb, roller rockers, ported heads, detroit locker, posi front, 4 wheel disk, bla bla bla. I would love to find a cougar with a 351c 4v, and hide away headlights seq tailights.