need box design for alpine type r 15

I need somebody to help me design a really loud and efficient box for a Alpine Type R tuned to 34 hz. The maximum height is 15" Max width is 40" max depth is 23"

doing it fiber glass or just a box for it


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Ronald Bailey Owner/ Installer of VIBRATION CUSTUM SOUNDS. CUSTOM BOX DESIGNER AND BUILDER
TID-896 7" screen,Amp-BX1206d
4/0power/ground cables
4-12 mofos 12ft3 box tuned 40hz DB:163.1

its just a box

Probably should use the whole airspace available, build a good braced box and net about 5.25 to 5.5 cu ft.  Put a slot port vertically up one side of the front baffle, 3.5" x 13.5", 14" long (deep).  Round off port edges including in the inside of the box, and round off the back side of the driver cutout.

That's not going to be the best SQ you can get out of that sub, but it will be loud.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

ok thnx, yeah thats what i am doing with 4 cu.ft @ 35 hz. thnx. I was just worried about the air velocity in the ports, but i will round em out.

You'll need to make the port 20" deep (still 3.5 X 13.5 area) with net 4 cu ft box airspace.  You might have to put a 90 degree bend at the end;  you want to be sure to allow at least 3 or 4 inches of airspace between the end of the port opening and the wall.   Port air velocity will be low and quiet with that port opening size.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

i dont understand what you mean by "be sure to allow at least 3 or 4 inches of airspace between the end of the port opening and the wall. "

When I plug that port into WinISD I aam getting 80 ft/s and in order to avoid port noise it should be under 55 ft/s

the port is 3.5 inches wide, so the the end of the port that is inside the box needs to be atleast 3.5 inches from a wall. if it gets too close to a wall you need to make a 90 so the entire port will have the same width from beginning to end. and round off any edges if you can.

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thnx but I decided to go with a port that is 13.5 x 5 x 32". I got this:

1200 watts?  We are talking about one sub?

Maybe be a little more realistic with wattage so you can keep that port structure at a minimum.  The more volume you give to the port because of the very large opening area, the less air volume you have available for the driver...and the worse the low end drop off will be.

Use real RMS numbers and allow higher port noise than you would for a SQwannabe setup (the criteria is 10% Mach or 110 ft/sec for a vehicle, not 5%.  This is SPL, not SQ.)  Remember, your concern for this project is "really loud and efficient".  Keeping box volume (dedicated to the driver...not the port) as large as possible will be a plus in the efficiency department.

Also note whether you have port air velocity valued at "peak" or "RMS" in your program.  If it's showing peak, change it to RMS.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

trust me, changing the port from 3.5" to 5" wont do anything for port noise. 3.5 is about the same i use for the port for the box for my 18SX. adding port area will only increase your port length while trying to keep a similar port tuning frequency. 3.5 X 13.5 is still a HUGE port for that sub. mine is only 3 x 18 x 28ish and i get NO port noise that i can detect

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oo ok thanks alot guys !