Box for two DD 1508's - Got questions..

[westman995 10+ year member]

Ok so im pretty sure im gona build a custom box for the rear of my 82 Trans Am. I got two DD 1508s on their way to me. So i am wondering what is the absolute best box size for the 1508? I want to get maximum output and really surprise some people with these little things. I should have more than enough room to go ported with these little subs, i would image. I think i got under 3 cubes to work with in my area, so should be enough i think.

Another question is, Is there any calculators or sometihng out there where i can easily change like the heighth of the box to make it the correct volume, or how do i got about figuring out exactly what height to make it to get the right volume?

This is kind of like what the box will look like to go in the rear "well" area thing.. I was planning to do this for two 12s but decided no way in hell i can get enough cubes in that area for the two 12s. It should be real similar to this minus the top being bigger than the bottom, and maybe not quite as high due to not needing as much space with the 8s. The box was not drawn to spec, its much deeper than it really can be, was just drawn to show idea of the shape it would have been.

So more than likely ill be trimming the height off that box, and the top wont be quite as big like i said, cuz that was to fit some 12s.

Can you recomend a box calculator that you can figure out what size to make it to get the right volume?

I read that .9 cubes ported some guy hit almost 150 with a single 8.. Now would that be .9 cubes before or after sub and port displacement?

I am also going to do slot ports im pretty sure.

One more question, since im doing two subs. Do i want to put a divider between the subs and put a port on each sub, or just build one big box with no divider and only one port? Im thinking with a divider is the way to go, but dono for sure.

Click to read more...

 

[loudmofo 5,000+ posts]

the box i built for both is 1.7cb ft and ported at 28hz i sould have mine sometime next week so ill let you know how it works out

 

[westman995 10+ year member]

the box i built for both is 1.7cb ft and ported at 28hz i sould have mine sometime next week so ill let you know how it works out

Did you ever even use the subs i purchased from you? Sounds like you didnt. Ordered some more?

Is that without a divider then? I also read a bunch of times to tune it up to around 40 or so...

 

[loudmofo 5,000+ posts]

looking at you design and being in a firebird i would do 1 big slot the long way behind both subs have both subs in one chamber.

 

[loudmofo 5,000+ posts]

Did you ever even use the subs i purchased from you? Sounds like you didnt. Ordered some more?
Is that without a divider then? I also read a bunch of times to tune it up to around 40 or so...

i never used the subs i sold you i really wanted the platinum cones //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif so when i got payment from you i called dd and orderd them thanks again .

dd always recommends 40hz but i have tuned dd subs lower and they sound great i mite try making a loading wall for mine out of 1/2in plexi will have to test and see how they like 28hz.

 

[westman995 10+ year member]

If you think that will do best, ill prolly that way first. If i dont like it i would think it would be too hard to take the top piece off, add a divider and do two ports or something if i really wanted/needed to. So the slot in the very rear of the car?

I also read the 1508s need something to "load" off of? Which ive never really heard of before. But i guess it means it needs to have something to stop them from bottoming out. Do you think it will work fine in there? Or would i be better off trying to get them to "load" off of something. If i have to, my idea is something i read, to put plexi glass in front of it. It would give it a cool look and i wouldnt have to worry about anything falling on top of the subs while back there facing up.

 

[westman995 10+ year member]

i never used the subs i sold you i really wanted the platinum cones //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif so when i got payment from you i called dd and orderd them thanks again .dd always recommends 40hz but i have tuned dd subs lower and they sound great i mite try making a loading wall for mine out of 1/2in plexi will have to test and see how they like 28hz.

Ah, how much did those platinum ones run you? Well i heard alot of people say 40 or so just for the 1508s not really for any other subs, so i guess just have to do some testing/tuning to figure out how it really sounds best to your liking. Ill prolly be doing some testing of different hz too.

 

[loudmofo 5,000+ posts]

fire the subs and port up same design you have now just do the port 1st the long way closest to the hatch and subs in front of it and if you do the loading plexi like i plan on dont cover the port with it only the subs hope you understand what im saying.

 

[westman995 10+ year member]

Yep i understand what your saying im pretty sure. Fire sub and port up like i planned. Port all the way in the back of the car, and the long way. And dont cover the port with the plexi haha.. I think the plexi would be a great idea to protect the subs also. So i really want to do that.

Ive got lots of questions cuz the only boxes ive actually built before were just sealed boxes built to specs.. Nothing special there. Im fairly new to the building ported boxes.

 

[loudmofo 5,000+ posts]

yes thats the idea the type of car you have works great with subs up and ports up the plexi does look good i seen it done a few times the best was lcrx with the box of 4 8s in the crx he has done alot of testing and used them the most i would pm him also.

 

[westman995 10+ year member]

Ya i seen he had some before also. I will PM him about some specs and to see what he has liked best since he also used them in a hatch, not real similar car but its still a hatch.

 

[westman995 10+ year member]

Ive read stuff about like "dead space" or whatever on some boxes, does that really happen? Is it possible to have problems with my design where its bigger on the top than the bottom?

I had another idea, depending how high i want to build the box, i may not even need to make the top of the box bigger than the bottom.. I could just make the top baffle big enough so it covers all around the rear to look nice. Ill do a little sketch up quick to show.. Depends how it looks in the rear with it being that high tho.

 

[loudmofo 5,000+ posts]

Ive read stuff about like "dead space" or whatever on some boxes, does that really happen? Is it possible to have problems with my design where its bigger on the top than the bottom?
I had another idea, depending how high i want to build the box, i may not even need to make the top of the box bigger than the bottom.. I could just make the top baffle big enough so it covers all around the rear to look nice. Ill do a little sketch up quick to show.. Depends how it looks in the rear with it being that high tho.

thats what i would do also make the top like a trim panel no need to make this box super big i would start with 2.2cb before sub and port displacement.

 

[westman995 10+ year member]

Ya that design above was to get max volume for some 12s at first. Should be quite a bit easier doing it for the 8s not having to squeeze as much as i can out of the space. Even tho you already know what i mean, here some pics.

Also, would the port work like this, or would i be better off doing the subs in center and port right behind? I kind of like the offset look having them both to one side.

But, one problem. I may not have quite enough room to make it the right size by doing it this way. It all depends on how high i want to, or can make the box. I dont want it sticking up real high. Idealy i would like to have the plexi be flush mount with the rear floor area.

Pics of the rear of my car.. To see where i want the plexi to be flush with. Yes i know its dirty, ive since cleaned up the wiring, its not a great car but its what i got right now.

 

[loudmofo 5,000+ posts]

Ya that design above was to get max volume for some 12s at first. Should be quite a bit easier doing it for the 8s not having to squeeze as much as i can out of the space. Even tho you already know what i mean, here some pics.
Also, would the port work like this, or would i be better off doing the subs in center and port right behind? I kind of like the offset look having them both to one side.

But, one problem. I may not have quite enough room to make it the right size by doing it this way. It all depends on how high i want to, or can make the box. I dont want it sticking up real high. Idealy i would like to have the plexi be flush mount with the rear floor area.

i wouldnt make the port like that i would do it on the length of the box the long way if you dont have the room just place it on the drivers side from top to bottom