2 12" alpine type r's in my custom ported box

 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 1
Registered: Sep-08
Hello everyone i am building a custom ported box by myself for my 2 12" alpine swr-1242D. I have read alot about building boxes and how everything works but now i just want to see if all my calculations are right. Ok so my box dimmensions are (lxwxh) 35x15x15. Im going to put a divider in and minus 4 inches in the front because im gonna make it snazzy and put a piece of plexiglass across the front and have neons and leds inside. Well anyway it came out to 1.671 ft3 for eachside of the box without calculating any ports or anything. Now i calculated the ports with this http://www.reaudio.com/speaker_box/LPort_Box_Calc.html I tuned the box to 37hz( is that a good frequncy for rap and techno?)It came up with a width of 1.5, height of 14.5 and a length of 26 inches for a slot port on each side. And now its 1.33 ft3. is that correct? IM using 3/4 mdf. i want it to be superrr loud and be able to set off car alarms.
 

Platinum Member
Username: Nyyfan13

15 Mag USA

Post Number: 10353
Registered: Jul-06
My supper is usually relatively quiet because I am too busy eating....but sometimes I have the TV turned up kinda loud I guess.....
 

Gold Member
Username: Somedonniedude

Illinois United States

Post Number: 2005
Registered: May-07
The box isn't big enough... aim for around 2~2.25cf per chamber after port displacement. If you want to hit lower I would tune it around 32-34hz, but 37 might be ok for what you listen to. Maybe aim for around 22~26 sq inch port opening for each port. See what this leaves you with...

Hopefully some people that have first hand experience with R's can give input.
 

Gold Member
Username: Mixmastaspig

Team RD, Canada

Post Number: 1858
Registered: Sep-05
@Yanks

LOL

I can't tell you anythign about the box dimensions you have listed but 37hz is decent for bass stuff.
 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 2
Registered: Sep-08
Crutchfield says a ported box for this sub should be between 0.75-2.0. so i thought 1.3 would work out pretty well. i cant really make the box bigger because i have a jeep wrangler and those are like the max dimmensions i can use. and the sq inch port oppening comes out to 21 so that should be fine.
 

Silver Member
Username: Ducka

Houghton/Hancock while..., MI United States

Post Number: 475
Registered: Jan-08
your gunna want closer to 2+cuft per sub. I have the same subs. I have a box built to 35hz and it sets of a few alarms. Ive got plans for a new box, but their kinda secret.

But yeah go for 2-2.25cuft per chamber and 37 is a good tuning level.... How are you going to have it divided with only one port?
 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 3
Registered: Sep-08
No i divided it and made 2 ports one on each side for each speaker ill upload a pic.

could you maybe provide me with your plans haha? the only problem is that i have limited room so thats why i came up with such a small box. and would the 2.0 ft3 be including the port length and stuff? Would i be better of making it a sealed box?? i want to do this prject this weekend so i appreciate eveyones help if you can give it to me

Upload Just a rough sketch
 

Silver Member
Username: Ducka

Houghton/Hancock while..., MI United States

Post Number: 477
Registered: Jan-08
Easiest way would be to ditch the plexi, cuz you'll lose a lot of output by not porting it

If you want my design I have now i can give you that... I just used the re enclosure. Sorry but the new design isnt for sale lol. Not till I build it atleast.

if you wanna do it your way i would suggest aero ports(if you dont know what they are google them). put 1 4" areo on each side and you can figure out the length with this calculator.

http://www.carstereo.com/help/Articles.cfm?id=31

the bottom one

Make sure this box is like 4cuft(total) unless you dont have the space. Mine currently is 3.8 and it sounds decent.
 

Gold Member
Username: Somedonniedude

Illinois United States

Post Number: 2007
Registered: May-07
Where you wanting to put a piece of plexiglas over the front of the subs? If so that's a bad idea. Your box would be a disaster fyi.

Go sealed. I installed 2 12"s sealed (about 1.25cf per chamber) and it was a tight fit. I don't see a ported box fitting very easy, unless you go above the seat/window line.

Also, Can I ask what amp you are using for these? Hope you current electrical can support it.
 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 4
Registered: Sep-08
Well how about me going with one 15? i was just reading about the Alpine SWR-1542D and they got really good reviews so how about i take that box im building and make it tro fit 1 15" type r and make it like 3.5 ft3 with a port to tune it to 35 hz? i think that would be a really good idea but i dont know. but may i ask a question why is the plaxiglass is a bad thing? so now i might just make a slot on the one side of the box in the front to display my amp with a piece of plexiglass? in my opinion that would be cool but if its gonna break or do something bad i wont do it. and i was thinking about using a Hifonics Brutus 1608D is that any good?? i would like to push the sub about 900 rms
 

Silver Member
Username: Ducka

Houghton/Hancock while..., MI United States

Post Number: 479
Registered: Jan-08
you could use your design just put the sub or subs on top (not on the plexi) that way looking through the plexi you could see the magnet. I dont suggest putting the amp on the box... that is a good way to damage it. I think using your idea have the plexi in front and a 15 on top and take out the divider. You could make the box around 3 cuft and i think that would give you enough airspace for the sub and enough to port it.
 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 5
Registered: Sep-08
i was thinking about your idea and i like it. but wouldnt that blow the plexi glass out though?? the reason i wanted the plexiglass was to protect the front of the sub from getting punchured and thanks for all your help.i made the box (lxwxh)35x17x15 In the re calculator the box is 4.0 cubic feet withoug the port and then when i add the port its about 3 cubic feet. port is 3 inches wide, 15 height and 26 inches long
 

Silver Member
Username: Ducka

Houghton/Hancock while..., MI United States

Post Number: 484
Registered: Jan-08
It won't blow out if you have it in securely. If you did it your original way it would be like a bandpass box, but it wouldn't be properly calculated so it would sound bad. If your worried about the sub just get a grill for it.
 

Platinum Member
Username: Rovin

1 15 = 149.5 DBsTrinidad & T...

Post Number: 14165
Registered: Jul-05
u should use around 2cuft\sub tune it to 35hz ...use aeroports if u dont have much space ...
 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 7
Registered: Sep-08
Alright i went with the idea of a 15 inch type r. And i dont want a grill cause i want to enlose the sub so it looks cool with the leds but if you think it will really sound shitty i will just get a grill. also another question is a Hifonics brutus 1608D a good amp?? and my new port came out to be 3 inches is that ok or would that be too big of a slot hole???
 

Silver Member
Username: Ducka

Houghton/Hancock while..., MI United States

Post Number: 485
Registered: Jan-08
I meant get a grill if your worried about the sub getting hit with stuff.

Dont put the plexi over the sub. If you want a plexi window just put it on a different side from your sub and you can put the LEDs inside the box.

That amp is pretty good.

and the port is 3inches wide or what?
 

New member
Username: Hunter77

West milford, Nj United states

Post Number: 8
Registered: Sep-08
the port will be on top of the box 3 inches wide,15.5 inches height, and 27 inches long.(35hz) ive never seen anyone with a 3 inch wide slot port so i was wondering if it was alright??? and i found a good way to seal my box and make it like concrete, you get some fiberglass resin and slosh it around inside the box and let it sit untill dried, i read that it will cover up the pores in the wood and it will almost make the box unbreakable! thanks for all your help ill post pictures next week
 

Silver Member
Username: Ducka

Houghton/Hancock while..., MI United States

Post Number: 493
Registered: Jan-08
Yeah that width sounds decent. I have never done the resin thing but that seems like a reasonable idea. Happy box building!
 

Platinum Member
Username: Rovin

1 15 = 149.5 DBsTrinidad & T...

Post Number: 14175
Registered: Jul-05
that resin thing is what steve meade does often in his builds - i never tried it b4 though ...
Jump to: Home Audio Forum | Home Video Forum | Home Theater Forum | Car Audio Forum