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imhungnurnot

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Posts posted by imhungnurnot

  2. Posted

    Ok so here we go. The box will be roughly 1.215 cuft after displacements. The radius of the curve will be 2 inches and will be used for volume. The port will be 2x9.5x34.75 (disregard the 35.25 on the sketch) which will tune the box right at 33Hz with 15.64 square inches of port area per cube of volume. Here are some VERY rough sketches.

    Photo0049.jpg

    Photo0050.jpg

    Photo0051.jpg

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  5. Posted

    There is more to it than that. You need to basically fiberglass the pod onto the metal floor of the car. You then have to vent the pod somewhere to get enough volume or your speaker will be choked. In order to do this cutting of sheet metal is usually involved =(

    There is already a hole in the metal behind my kick :) its about 3x4 inches i guess.. but that will be plenty..

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  6. Posted

    If i increase the width to 30 that will give me 32.12 hz

    And 9.10 cu^3

    Im not good with measuring port area and what it should be relevent to the size of the box for it to sound good tho.

    Measuring port area isn't shit. You probably just think its more complicated than it really is. When you look at the front of your box, the port is a 2 dimensional rectangle. Right? Well the area of this rectangle (base x height) is your port area for your box. When you talk about port area, you talk about it as a ratio between port area and the net volume of your box. Fi recommends 12-16 square inches of port area per cuft of net volume. Lets say the area of this is 100 square inches and the box is 6 cuft (net volume; meaning after sub and port displacement). You divide the total port area by the net volume of the box (100/6) and you get 16.7 square inches of port per cube of volume. This is a little above the range which isn't a problem except for a long port. Sometimes port area has to be decreased so the port length will be decreased so the box will fit into the space your have in your vehicle.

    However, if you increase your port area, the port length needed will have to be increased to stay at the same tuning. So lets say i cut down the port area of the box from 100 to 80.. (the port will have to be shortened to keep the same tuning; so it will displace less volume so your subs will have more net volume now) lets say your net volume is now 6.5 cuft. Now 80/6.5 is 12.3 You're still in the range so its good.

    It's really a number game.. sorry if this is hard to understand.. read it multiple times if necessary.. :popcorn:

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  8. Posted

    Try the downfire method or you could try side venting into the cab corners.

    My original plan was sub up, external port into the passenger side corner so I could switch tuning easily. But I think I'm going to put a battery there. Now I'm leaning toward the idea of porting out of the front with the flares (like in the picture).

    I'm thinking about firing the sub like the drawing, but maybe decrease the angle so its closer to a downfire setup. But i'll still have an angle on it so the sub will be able to breathe and it may create a horn type affect with the angle.

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  12. Posted

    It's all completely car dependent.

    Unless you know someone with the same vehicle and has tried multiple locations, we can't tell you for sure.

    Yes i know.. but in general thinking about a single cab. With my current box, it loads off of the roof which is pretty far away. And it may be harder to compress the air in my cabin because it can easily flow out of my windows. I've heard that utilizing the reflection of sound waves in your vehice (loading) helps with something or other? Not sure if its SQ or SPL. Any thoughts?

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  13. Posted

    well im trying to keep the spare tire, Idont want to but im being forced to. and so i measured it (finally) and it is 11" deep into the trunk. i would like to keep the design but i dont know if i can. and im pissed off cause i was starting to like the idea.

    It'll definitely work.. I'll punch some numbers tom at work and let you know.

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  15. Posted

    something I wish I would have never showed pics of

    Don't get me wrong. You're a bad ass builder, but it's basic geometry. Someone would have figured it out anyway. Hell i didn't even calculate anything on mine. Just cut and tested it. If you make more cuts then necessary it doesn't matter because you are going to glue/glass the shit out of it.

    Photo0038.jpg

    Photo0043.jpg

    Photo0042.jpg

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  16. Posted · Edited by Im Hung N ur Not

    DON'T BUILD THAT, YOU'RE BUILDING A DAMN WHISTLE.. LOL THATS ONLY 3.4 SQUARE INCHES OF PORT PER CUBEEE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :ohnoes9:

    How many subs do you have? and what size?

    That is just a rule of thumb and does not always apply, I actually HATE that little "rule" because the port MUST be designed to suit the woofer, not the enclosure it is in.

    He's using 7.6 cuft.. he's gonna have a lot of cone area.. he isn't building this for a 6 inch woofer.. more like an 18.. and for high excursion woofers that rule of thumb is necessary. At the very least he'll need to flare the port on both ends

    Port Area Calc.

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  17. Posted

    Sorry.. I didn't answer that. 1.1 cuft per sub. Remember this is a approximation, but a good one. You told me about 2.6 cuft total.. So I designed it assuming exactly 2.6 cuft total. So you'll probably have a +/- on the tuning of 1 hz at the very greatest. You won't be able to notice this though..

    Idk about firing the ports just on one side.. You may get port loading because of the hump in the middle isn't going to allow the air on the passenger side to "see the port" as much as the air on the driver side. i would try to put one on either side of the box firing out of the front.. You can try to put both on the driver side and see how you like it. Or we could get a more experience member on here to help us decide.. Port tuning isn't hard for me now.. The hard part is deciding where to fire sub/port if you have options

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  18. Posted · Edited by Im Hung N ur Not

    Not trying to hate on you.. but those rims have to go.. there's too much going with them.. you need a clean 5 or 6 spoke rim with a nice size lip.. also.. this will be MUCH easier to clean..

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  19. Posted

    DON'T BUILD THAT, YOU'RE BUILDING A DAMN WHISTLE.. LOL THATS ONLY 3.4 SQUARE INCHES OF PORT PER CUBEEE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :ohnoes9:

    How many subs do you have? and what size?

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  20. Posted · Edited by Im Hung N ur Not

    cant add a divider, the box is 19" on the drivers side bottom and 20 on the passenger side.

    can i do two 3" ports?

    Make it the same on both sides so the box is symmetrical and divide it. You won't loose much airspace, and the divider will be an awesome brace for the top piece.

    3" ports are only 7 inches of port area per port.. I did the numbers.. 1.1 cuft per sub. 2 3" (one on each side) 14 inches long.. but its only like 6.5 sqaure inches of port per cube.. 3 inch aeros will be the way to go unless you can flare the 3" pvc.

    im not too worried about the divider.

    seem like aero's are what i need with my strict space requirements.

    so how much net volume will i have with 2 3" aero ports tunned to 33hz?

    my box is basically done so im stuck with it. haha...

    DSC_0658.jpg

    I see.. ha. The its basically gonna be the same as with the 3 inch ports , but you add another inch to the port length.

    Do two 15 inch long ports (from flare to flare; i.e. end to end). You will still only have 6.5 square inches of port per cube. However, you can get away with a 50-75% port area reduction with aero ports because they significantly reduce port air speed. So since 12 square inches per cube is the minimal recommended port area per cube, 54% of this is 6.5 square inches of port area per cube. There you go; you are in the 50-75% range!!

    This should be a clean sounding setup. You're going to downfire the subs? Port out the front or side?

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  21. Posted

    the radius would be 6" i think that might get me the amount i need, it can also be smaller. thats the maximum.

    There is one more piece of information I need. What is the max depth of the of the left side in the top view. (the part where the ports are firing in your drawing)

    just found out the maximum depth of the box can be 11". So I'm going to scrap my idea And just build a normal box. Is 11" too shallow for a 10" FI BL

    You're design will work.. why do you want to scrap it? I'm looking for this dimension in this picture..

    Photo0047.jpg

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  22. Posted

    Mtx makes their preloaded enclosures using ports like this. A port is a port as long as it has enough port Area and tuning frequency typically doesn't mAtter if it's square, triangle, flared etc. As long As you have those two you're okay. But I think it's just a thing with Mtx besides them I know of no one else who does their ports like that. Nor do I know how to calcualte it

    Yeah, but a trianglular port with a rectangular opening???

    Shouldn't matter.. ports are tuned by area and length. So the cross sectional area of the triangle should be equal to the area of the rectangular opening. Do the numbers. Let us know if this is right..

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  23. Posted

    Heat the end of the PVC with a torch. (careful not to burn it, just heat it)

    use a bowling ball (for large ports) or funnel (for smaller diameters), push the heated pvc on the item to start the flare.

    Finish it off by re heating the edges and forming the rest with a crescent wrench. (as a small hand brake)

    test for uniform molding by setting the flare on a flat surface.

    Remember to take you're time!!

    Don't try to form it all perfect the first time you go at it.

    If you go too fast the pvc will split or warp to an un-usable piece.

    ~or~ by aero ports.....

    Sounds like something fun to try! :fing34:

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  25. Posted

    cant add a divider, the box is 19" on the drivers side bottom and 20 on the passenger side.

    can i do two 3" ports?

    Make it the same on both sides so the box is symmetrical and divide it. You won't loose much airspace, and the divider will be an awesome brace for the top piece.

    3" ports are only 7 inches of port area per port.. I did the numbers.. 1.1 cuft per sub. 2 3" (one on each side) 14 inches long.. but its only like 6.5 sqaure inches of port per cube.. 3 inch aeros will be the way to go unless you can flare the 3" pvc.

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