[flip888]

I got an Alpine type R 12" today and on the paper that it came with it says what the optimal ported box dimentions are but i was just going to build the biggest box i could fit. It was going to be like 30x25x12 or something. Theirs is 18x13.5x16.5.

What should I do to get this thing to be as loud as possable? Build their design or mine?

 

[RE's 97 gs-t]

That word optimal has a meaning. It means that you will get the best sound from their size box. You can vary the dimensions as long as the interior volume matches the recommended volume.

 

[flip888]

ok cool i see, so if the internal dimentions were bigger than what they say i should make them i wont get the best sound then.

Where can i find info about building a vented box for a 12" Alpine Type R all i know is that it should be 18x13.5x16.5. i dont know how big to make the vents or anything.

 

[keclipse]

ok cool i see, so if the internal dimentions were bigger than what they say i should make them i wont get the best sound then.

Where can i find info about building a vented box for a 12" Alpine Type R all i know is that it should be 18x13.5x16.5. i dont know how big to make the vents or anything.

i would consider buying a pre-built vented box, because making one isnt as easy as it sounds i dont think, you have to put the vents in a certain place for it to sound up to par

 

[flip888]

where could i find a box designed for this sub. or would it have to be custom?
I already got the fiberboard. All i realy need is to find a pic of what the box looks like with the top off. My friends will probalobly help me out if i get lost tho.

Where should i look for the box design?

 

[forcdndukshun]

I would do an online search or maybe pirate a box building program off of limewire. The dimensions aren't as important as air space. The required air space should be listed in a spec guide that you recieved with the sub. It should have requirements for ported/vented and sealed enclosures. It is listed in cubic feet. Once you know the air space you are looking for you can change the dimensions of the box to anything you want as long as you meet the requirement for air space. You calculate air space my multiplying length, hieght, width and then dividing by 1244. It doesn't have be spot on but the closer you are to that number the better the sound.

 

[Dragonstalon]

There is a program out there called BlauBox that has been around for years. It's a great program, though it is a DOS based program it is still one of the best out there.

 

[RE's 97 gs-t]

I would do an online search or maybe pirate a box building program off of limewire. The dimensions aren't as important as air space. The required air space should be listed in a spec guide that you recieved with the sub. It should have requirements for ported/vented and sealed enclosures. It is listed in cubic feet. Once you know the air space you are looking for you can change the dimensions of the box to anything you want as long as you meet the requirement for air space. You calculate air space my multiplying length, hieght, width and then dividing by 1244. It doesn't have be spot on but the closer you are to that number the better the sound.

You divide by 1728 not 1244.

Conversion Factors

- cu in / 1728 = Cubic feet
- cu ft x 1728 = Cubic inches
- cu ft x 28320 = Cubic centimeters
- cm x 0.394 = Inches
- in x 2.540 = Centimeters
- ft x 30.48 = Centimeters
- ft x .3048 = Meters
- m x 3.281 = Feet

 

[RE's 97 gs-t]

ok cool i see, so if the internal dimentions were bigger than what they say i should make them i wont get the best sound then.

Where can i find info about building a vented box for a 12" Alpine Type R all i know is that it should be 18x13.5x16.5. i dont know how big to make the vents or anything.

I did a calculation of that box size and it comes out as 1.71 cubic feet of internal volume. The dimensions that Alpine listed are external dimensions so to calculate the internal volume you have to subtract 1.5 from each dimension which is the thickness of the MDF (two boards per dimension).

 

[MNcordia]

I found bassbox pro off of torrents, it's kind of handy for stuff like this, but it nothing you can't do on paper.
Your sub's sheet should have the recommended port length and diameter.

 

[boostola]

The vented enclosure for an Alpine R type 12" is 1.75 cu ft gross volume. The vent area is 15 square inches by 22.75" long (Yes the port will have to turn!!) The 1.75 cu ft already includes the displacment of the woofer and port... so don't add them.

 

[flip888]

wow im in over my head i think. i looked for bassbox pro and BlauBox but didnt seem to find them. i did find http://www.caraudio.com/forum/showthread.php?t=137804 though. is there a design in there like the one that i should build?

 

[gearbasher]

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[JungulSouljah]

I would do an online search or maybe pirate a box building program off of limewire. The dimensions aren't as important as air space. The required air space should be listed in a spec guide that you recieved with the sub. It should have requirements for ported/vented and sealed enclosures. It is listed in cubic feet. Once you know the air space you are looking for you can change the dimensions of the box to anything you want as long as you meet the requirement for air space. You calculate air space my multiplying length, hieght, width and then dividing by 1244. It doesn't have be spot on but the closer you are to that number the better the sound.

This is the worst advice Ive heard anyone give. Limewire?!? What are you deficient? Yeah download off of limewire and watch what happens.
No more of adding your 2 cents if you have no clue what you're talking about.
Find a PROFESSIONAL installer and ask him/her about your specific vehicle and equipment.

 

[gearbasher]

This is the worst advice Ive heard anyone give. Limewire?!? What are you deficient? Yeah download off of limewire and watch what happens.
No more of adding your 2 cents if you have no clue what you're talking about.
Find a PROFESSIONAL installer and ask him/her about your specific vehicle and equipment.

Wow the best advice so far....no offense but this what I get paid for.

 

[volvodriver]

the math I've done says the R12 is best suited for a SEALED enclosure. of course if you really just want LOUD LOUD LOUD bass the thing will pound like the fist of an angry god in a properly ported box...it'll just sound way better sealed.

I've heard them sealed and ported...sealed ftw

edit// and by properly, i mean according to the dimensions given by the manufacturer, and then tuned with an osciliscope to the recommended resonant frequency.

 

[mystilexzero]

honestly, if you port it it would be wayy to much spl's and not just that they bass wont exactly be hitting as accurately as you would like, for small enclosures i found the best was a sealed enclosure inside an eclipse, or any type of hatch. UNLESS your willing to dump cash for a premade box then definately go for a double band pass, accurate and will knock your socks off, i personally love big boomy bass so i will be going with a DBP box. its really up to you and how much work/ money you would want to spend. There are alot of car audio forums out there that support on building your own boxes, maybe snoop around there for half n hour n see what you can find. Btw ported boxes are bit more harder than sealed mainly because ported boxes are bigger and placing the port holes makes a big difference, whereas sealed its like wrapping up christmas presents =) have fun

-Aaron