Need HELP with Dual Sundown SA-15 Enclosure

[brianm113]

Hey guys, so I know I am a "noob" on here but i have been a major fan of the site for a little while now and have now finally come to needing to register hoping for some help from the pros haha...well anyways for a couple months i had a couple of rockford p3-12s in a ported Ground Shaker prefab box in the trunk of my 93 buick century powered off a rockford r1200-1d..the amp birthsheet said 1370....I was VERY pleased with the set up but obviously wanted more. I decided to buy a pair of sundown sa15 d4s and a ported Ground Shaker prefab again...the box is about 3 cubes per chamber with unknown tuning...I planned on just barely squeezing the box in the trunk but sonic's dimensions were just an inch off in width...making it too wide to fit between my trunk hinges. I already had the back section of my rear seat removed with a trim panel made of mdf in its place. so I decided i might as well bolt them to that in the back seat, facing sub up port up. It sounds like SHIT. It doesnt sound like bass AT ALL, just like the mechanical sound of the subs kinda. when I cover the port with my arm a bit it gets a little bit louder and more "bass-like"...but still doesnt do to much. Doesnt seem as if nearly as much air is getting moved out of the port as should be. So i figure I need to build a box....or does it just maybe sound bad because of my positioning of the box? I can post pictures if need be just a little late now and i dont have any yet...just got the box in a couple hours ago. If in need of a new box design, I have access to a woodshop to build the box but I have trouble completely understanding the concept of box design, being 18 years old and just starting what I would consider my first "real" system. (although just about any of you guys could make mine sound like an alarm clock radio lol)....but could anybody maybe whip something up for me or anything? sundown suggests 3.5 cubes per sub, tuned at 35...doesnt matter to me whether it's sub up port up, sub up port front, sub front port up, sub front port front...whatever would make a good daily setup with a bit more emphasis towards spl...if that makes any sense...It would be greatly appreciated...I can provide whatever additional information may be needed

[Joe X]

2 15s in a trunk is going to be hard, post max dims for a box that you can fit into the car or maybe you will need to build inside. also what vehicle is it?

[brianm113]

2 15s in a trunk is going to be hard, post max dims for a box that you can fit into the car or maybe you will need to build inside. also what vehicle is it?

They dont have to go in the trunk, can stay in the back seat like I have them....Ill post some pictures a little later....but the biggest i can go in the back seat is 44x24x18 if I put the box in through the front doors....The car is a 93 Buick Century Sedan

[brianm113]

heres a couple of crappy camera phone pictures

[brianm113]

thinking about just going sealed in the trunk...found a prefab thats almost perfectly 2.5 cubes per chamber, same as sundowns recommendation...I have found that my old p3 12s are a LOT louder in the trunk than they are in the back seat position that i have the 15s in. So I am hoping by putting the 15s in the trunk sealed I will still get higher spl than the 12s but also have a little sq Key word: HOPING.... any ideas?

[Joe X]

You do have the space for those subs in the backseat ported, backseat boxes usually don't do very well (but not always), if you are not heavily into low tuned music do the sealed or if you are give dimensions inside the trunk assuming you will be building inside, 3 - 3.25 per sub would still work, you just need to push some more power.

[brianm113]

You do have the space for those subs in the backseat ported, backseat boxes usually don't do very well (but not always), if you are not heavily into low tuned music do the sealed or if you are give dimensions inside the trunk assuming you will be building inside, 3 - 3.25 per sub would still work, you just need to push some more power.

thanks man, yeah i kinda figured it wouldnt do too well anyways. I put my p3s in the same position I had the sundowns in and it also didnt sound very great...but definitely sounded better than the sundowns. I do plan on "upgrading" to a hifonics brx2400.1d (idk if going from rockford to a hifonics is really an upgrade, but xD) or getting another r1200, but I could only get 800 rms at 2 ohms from each r1200 (the sa's are dual 4 ohm)...so most likely gonna go for the hifonics. so i guess ill see how they do sealed up on 2400 and then see where we go from there...maybe pick up two more sa's and do a wall?

[brianm113]

ok so I got the sundowns in the trunk sealed running on my r1200...have heard some bad things about hifonics so i have decided to go with the lanzar opti3201d...does 2100 rms at 1 ohm, 3200 at .5. The 15's definitely brought in the lows I wanted, but sealed up they aren't much louder than the 12's were ported. So I am thinking about building ported in the trunk, but am curious as to whether I should build it with the subs facing into the car, sealed off from the trunk at the back seat, or just build inside the trunk with them facing to the back? I am just hesitant to build them facing towards the back because it seems like there wont be much space left around the box for the air to flow forwards...any ideas?

[81000D]

Towards the cabin so the port can breath.

[TylerParrish]

I've always found it to be louder if it's FULLY sealed off from the trunk facing forwards, but that's not always the case with everyone.