Box design for fi Q 18 done need the "go" signal

[Xprime4 10+ year member]

after losing some hair, some patience, few hours and some sleep, i finally think I (with the help of few) think i've got something ok. I ain't good with design software so there won't be any pics before the build start but i just need a confirmation on what i'm doing //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Box will be 37,25 width x 21 height x 22 deep = 8.261 ft/cu before all displacement

Sub = fi Q 18 (27mm xmax) and .24 ft/cu displacement

Tuning expected = 30-32hz no more/ no less

Power will be around (+/-) 1500 watt rms from bxi1606d @ 1ohm. I may set it around 1400 for safety purpose.

Aeros port will be pvc tube from home depot of 4 inch. (i think it's internal)

I've used carstereo calculator but still... they told me i need at least 12.99 inch of minimum diameter (i'm at 16) and minimum 132.53 inch of port (i'm at 754.93???//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif).

Calcul: P x 2square x 13.01 x 4 aeros = 755inch/cu.

The 13.01 comes from carstereo calculator for 32hz in 8.3 but i'm not sure i need to input the net volume (after sub/port displacement) or the total internal volume before all displacement //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

The aeroports will be on the left and right side of the box 2 per sides. Sub facing the roof of the accent 99 hatchback.

There is no other way of doing it coz of aeros cleareance issu.

I know i need some kind of bracing to help the aeros straight, what could i use? I only got acces to a local home depot //content.invisioncic.com/y282845/emoticons/crying.gif.ec0ebefe590df0251476573bc49e46d8.gif

How will the bracing displacement affect the tuning freq? should i make the port longer/shorter and am i doing something wrong? If i get the start signal i may start the box building this afternoon....

Please help a poor guy with no selfesteem when it come to tuning calculs.

Click to read more...

 

[Rashaddd 5,000+ posts]

Oh boy.......

 

[Xprime4 10+ year member]

Oh boy.......

oh boy isn't a lenght

oh boy what?

 

[Rashaddd 5,000+ posts]

oh boy isn't a lenght oh boy what?

You sure about that?

 

[Xprime4 10+ year member]

3.14 x 2square x oh boy = fial... pm me if you want 5 bucks with an accurate answer

 

[snoopdan 5,000+ posts]

You wont need to brace those areos with anything more than a shitload of liquid nails.

 

[Xprime4 10+ year member]

You wont need to brace those areos with anything more than a shitload of liquid nails.

really? what about the box? will an 18 destroy it if it's well done with my dimension?

rashaadd read your pms

 

[Rashaddd 5,000+ posts]

3.14 x 2square x oh boy = fial...

Now you're catching on

4 4" aero's need to be ~15 inches long each

This gives you 7.6 cubes net after all displacements @ 32hz

and you have 50 sq in of port

you're welcome

 

[RAM_Designs 5,000+ posts]

Don't worry about what the carstereo.com thingy says about minimum port diameter and/or area. If you're doing a slot port, 12-16in^2 of port per ft^3 is fine, you can probably get away with 10in^2 per ft^3 if using a PVC pipe, and maybe as low as 6-8in^2 per ft^3 if using aeroports. I've always used slot ports...they're cheaper and add bracing to the box, win-win in my book.

 

[Xprime4 10+ year member]

thank you all! I'll now be able to do something with some confidence. is there a problem of the aeros are facing each other (those on the left panel in front of those on the right panel) facing each other...

 

[Xprime4 10+ year member]

Don't worry about what the carstereo.com thingy says about minimum port diameter and/or area. If you're doing a slot port, 12-16in^2 of port per ft^3 is fine, you can probably get away with 10in^2 per ft^3 if using a PVC pipe, and maybe as low as 6-8in^2 per ft^3 if using aeroports. I've always used slot ports...they're cheaper and add bracing to the box, win-win in my book.

this is my 3rd box. the other two were slot and i this time around, i wanted to try something new.

Will i need some kind of bracing or it should be fine?

 

[RAM_Designs 5,000+ posts]

this is my 3rd box. the other two were slot and i this time around, i wanted to try something new.
Will i need some kind of bracing or it should be fine?

It never hurts to brace something. If you have any doubts just go ahead and do it; at least you'll have peace of mind.

 

[Rashaddd 5,000+ posts]

I'd just add a couple wooden dowels to the box where you can and where seems fit

 

[Xprime4 10+ year member]

I'd just add a couple wooden dowels to the box where you can and where seems fit

check yo paypal account //content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif hope you love canadian mony //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

is there any thing wrong with the port facing each other ? there won't be a lof of space between to two. maybe i'll be able to put them few inch away from each other

 

[Rashaddd 5,000+ posts]

check yo paypal account //content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif hope you love canadian mony //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
is there any thing wrong with the port facing each other ? there won't be a lof of space between to two. maybe i'll be able to put them few inch away from each other

Try to have 8 inches in the middle between them, if not, I'd just put them all on one side if they'll fit