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First Ported Build Alpine SWR-12D2 (Need Help)


EraOfDiscovery

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Hey everyone, this is my first post to SMD, so bare with me as it might be a little sloppy. But right now I am trying to build a ported box for my 2 Alpine SWR-12D2. I've lost so much sleep reading about porting because I really don't want to go through the time, effort, and wood to have a crappy ported box come out. As of right now I have them in a custom built divided chamber sealed box with 1.76 cubic feet per sub in the back of my 03 Chevy Tahoe. I've done all the research I can and I have some ideas in mind for a build. I read up on port area, port tuning, cuffing, you name it. I just would love a second opinion.

(Keep in mind thsee specs are for only half of the box with one woofer, as the other side will be mirrored, I just did this to save some time and math)

Enclosure 1:

Box Dimensions

H:15"

W:25"

D:20"

Port Dimensions

H:13.5"

W:3"

L:37"

Box Stats

Gross Vol: 3.40 ft3

Port Vol: 1.06 ft3

Physical Port L: 33.25"

Port Bends: Yes

Port Area Range: 27-36 in2

Port Area: 40.50 in

Port Area Per Foot: 18.08 in

Net Vol: 2.24 ft3

Tuning Freq: 33.36hz

Enclosure 2

Box Dimensions

H:15"

W:25"

D:19"

Port Dimensions

H:13.5"

W:2.5"

L:28"

Box Stats:

Gross Vol: 3.21 ft3

Port Vol: .70 ft3

Physical Port L: 24.75"

Port Bends: Yes

Port Area Range: 29-39 in2

Port Area: 33.75 in2

Port Area Per Foot: 14 in2

Net Vol: 2.41 ft3

Tuning Freq: 33.28hz

Thanks for any feedback you might have! Open to ANY ideas!

-Just trying to make the world a louder place, one decibel at a time...

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Firstly welcome to SMD.

ok if ive read this correct each of the sealed sections is 1.76 cubic feet which is too much for those subs according to the manual they need max 1 cubic feet per sub for sealed.

As for the ported they need max of 1.5 cubic feet each so for those boxes you designed their too big for the subs, unless ive read wrong and thats for both subs.

Heres a link to a box calculator if your not using one try designing the box with both subs in the one box.

http://www.stevemeadedesigns.com/board/topic/38791-torres-box-tuning-calculator-updated-818/

1998 Holden VS Statesman

Kenwood KDC-U556BT

Cadence CS2.65K

Pioneer GM-D9601

Alpine SWS-10D4

KnuKonceptz 0 Gauge

Response 4 Gauge

Execution Audio 60.4

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Your volumes sounds just fine to me, as well as port area. Those Alpines can benefit from a bump in airspace over what manufacturer recommends. Alpine recommends the minimum amount that the sub will work in to get the subs in the hands of the most users they possibly can. If someone has a choice between a sub that can sound good in 1.5 cubes vs 2.5 cubes, they are going to choose the sub that likes the smaller space. People(other than car audio fanatics) care about the extra trunk space that they don't have to dedicate to a sub enclosure.

OP, your idea sounds pretty solid. If I were you, I'd go forward one of these designs and see how it sounds. 4-4.5 cubes for 2 of those subs would sound pretty awesome I'm sure. It will absolutely stomp your current sealed box in compared output and dig lower.

The only thing I'd advise, since you're going from sealed to ported is DON'T grossly overpower the subs. You can get away with overpowering a sub in a sealed box much more than a ported one. The closed environment adds cone control and acts as an air spring(you may have stumbled across that while reading). A ported enclosure doesn't allow overpowering as much but benefits from low end output and authority and a bump in output at around tuning.

Im not the one you want to try to troll. Just a fyi for you.

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Firstly welcome to SMD.

ok if ive read this correct each of the sealed sections is 1.76 cubic feet which is too much for those subs according to the manual they need max 1 cubic feet per sub for sealed.

As for the ported they need max of 1.5 cubic feet each so for those boxes you designed their too big for the subs, unless ive read wrong and thats for both subs.

Heres a link to a box calculator if your not using one try designing the box with both subs in the one box.

http://www.stevemeadedesigns.com/board/topic/38791-torres-box-tuning-calculator-updated-818/

Hey Kerry95, thanks for the feedback :good: but i've read around and like CleanSierra said, these subwoofers can benefit from being in a larger box, Alpine just shows the smaller specs so more people will buy their subwoofer because it can fit in a smaller area and take up less space.

-Just trying to make the world a louder place, one decibel at a time...

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Your volumes sounds just fine to me, as well as port area. Those Alpines can benefit from a bump in airspace over what manufacturer recommends. Alpine recommends the minimum amount that the sub will work in to get the subs in the hands of the most users they possibly can. If someone has a choice between a sub that can sound good in 1.5 cubes vs 2.5 cubes, they are going to choose the sub that likes the smaller space. People(other than car audio fanatics) care about the extra trunk space that they don't have to dedicate to a sub enclosure.

OP, your idea sounds pretty solid. If I were you, I'd go forward one of these designs and see how it sounds. 4-4.5 cubes for 2 of those subs would sound pretty awesome I'm sure. It will absolutely stomp your current sealed box in compared output and dig lower.

The only thing I'd advise, since you're going from sealed to ported is DON'T grossly overpower the subs. You can get away with overpowering a sub in a sealed box much more than a ported one. The closed environment adds cone control and acts as an air spring(you may have stumbled across that while reading). A ported enclosure doesn't allow overpowering as much but benefits from low end output and authority and a bump in output at around tuning.

Thanks for the help. I have been bashing my head into the wall trying to design this and make sure everything is right so your input means ALOT. I'm really looking forward to the outcome of this box, but also know I have to take my time. If it were you building this, which one would you go with? I'm in a bit of a stump. Enclosure 1 has a net volume of 2.24 cubic feet, but the port volume per foot is a little high [18 cubic inches per foot]. With what i've read it should be between 12-16 cubic inches per foot. With Enclosure 2, the port volume is 14 cubic inches per foot [right in the middle of the recommended range] but the net volume after displacements is a little high [2.41 cubic feet] With what i've read with that it should be around 2-2.25 cubic feet. So with either box i'm going to have to make a compromise. As for the power to the subwoofers, each sub has a power handling of 1000 watts RMS and 3000 watts max. I'm currently running 2 Pioneer GM-D8601 amps [one per sub] and they put out 800 watts RMS and 1600 watts max so I shouldn't have a problem with over powering them [: Again thanks for all the feedback :good:

-Just trying to make the world a louder place, one decibel at a time...

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I'd go with the first one, since volume is closer to what you want. Please don't pay attention to "port per foot" as a sub doesn't care about that number. The sub cares about that total port area you're giving it. Honestly, either box you have listed, if designed and built right, should sound just fine.

Im not the one you want to try to troll. Just a fyi for you.

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I'd go with the first one, since volume is closer to what you want. Please don't pay attention to "port per foot" as a sub doesn't care about that number. The sub cares about that total port area you're giving it. Honestly, either box you have listed, if designed and built right, should sound just fine.

Alright, thanks for all the help! Just a couple more questions, I've read some things on "Port End Correction" I understand it a little bit but would I have to take it into account with my build? Should I add a 45 degree corner to my port? (Both in the corner and on the port wall to keep the length the same) I know it will cut the net area down a little bit but will it make a noticeable efficiency differency? Also, does sub orientation/placement matter? Can I have the sub on the top and the slot port running on the back and side wall? Would you place it closer or farther from the port entrance? Sorry for all the questions, just a box noob here and getting other options really helps!

-Just trying to make the world a louder place, one decibel at a time...

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From what ive seen everyone uses 45's at the port bend. As for the sub placement its all about testing as its dependant on the vehicle.

1998 Holden VS Statesman

Kenwood KDC-U556BT

Cadence CS2.65K

Pioneer GM-D9601

Alpine SWS-10D4

KnuKonceptz 0 Gauge

Response 4 Gauge

Execution Audio 60.4

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OP you are missing to mention what amplifier you are going to use, that's important parameter to decide on how to do your box specially because you picked dual 2 ohm subs and not D4s, also these are 5th generation Alpine subs not the SWR-1243 which worked fine in the 2-2.25 range on rated power, those 12d2 will likely sound peakier in a large box, make sure that's what you are looking for.

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He mentioned his amps Joe. Pioneer GM D8601. He didn't mention the voice cool configuration of his subs though to determine final ohm load at each amp.

I missed that these were the Gen5 subs that like a bit smaller box. I doubt the subs will fall on their face with 2 cubes a piece. At least not that's noticeable with every day listening. Low end extension should benefit from the extra air. And what are we taking about as far as that much "extra"? .25-.50 over suggested per sub? You and I know that the purpose of a ported enclosure IS to be peaky by nature. That's the whole point and purpose of design with a ported enclosure to get that bump around tuning.

Im not the one you want to try to troll. Just a fyi for you.

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