Box for fi Q 18" (what size, how much port)?????

[KickerAudio21 0]

Just got my 18" Q w/BP in the mail yesterday. (thx scott). Next week is spring break and I need a box design for the back of a 97 blazer. I have about 8 cubes to work with. Accordman from steavemeadeforums told me to go 6.3 ft^3 and 90 in^3 of port, which results in a 32-33 hz tuning. I have never worked with 18's before, and I've heard certain boxes for 18" Q's can really restrict their output. I only have about 1000 watts RMS from a bxi1206d to work with for now, but plan on upgrading to 1400watts rms.

My goal is to make a well balanced box. Not pure SPL or superlow tuning for SQ. I just want to get the most, good sounding output from the sub. And i'm a broke ass college student so I can't afford to play around with different boxes, i wanna hit it on the money first time.

here is a quick sketch i did. Top will be double baffle, and I will add some form of bracing. nothing is to scale, just a quick sketch to show you what design I plan on using.

[johnecon2001 82]

That looks like a great box.

[bodybuilding90 0]

That looks like a great box.

x2, thats one of my favorite box designs, great job

[j_black10 0]

That box will work. The only thing I would change is the tuning, 30hz instead of the 32-33hz.

[cLutcH 0]

Did you make th at design from scratch? Or is there a sub box calculating thing online. I want to make a box with that design except for a SSD15 tuned to 32 hz, 4 cubes.

[Accordman 0]

That box will work. The only thing I would change is the tuning, 30hz instead of the 32-33hz.

imo it wasnt worth the output loss at 30hz rather then 32-33 i tryed that sub in pretty much every hz box form 28-40

[j_black10 0]

That box will work. The only thing I would change is the tuning, 30hz instead of the 32-33hz.

imo it wasnt worth the output loss at 30hz rather then 32-33 i tryed that sub in pretty much every hz box form 28-40

I agree somewhat, but it shouldn't be that much output loss. I'm more about sound quality and those subs sound better @ 28-30hz compared to 32-33hz. They will have better control on the lower notes which that's what 18s are made for imo!!

I know mine got REALLY LOUD and LOW when I had them in the 28hz box compared to the other two which were 30hz and 33hz. 33hz was the loudest but didn't hit the low notes to my liking.

[KickerAudio21 0]

can someone tell me wtf 14.28 sq. inches per cubic foot means!???? My box will be in three dimensions, not two, so i have no idea what 14.28 inches per cubic foot means.

What i need is the number of inches ^3 per cubic foot. My box will be roughly 17.5" wide x 24-26 " tall x however many inches deep it takes.

6.3 cubic feet, 90 sq. inch port, 32 hz tuning is the goal.

PLEASE HELP ME I NEED TO START CONSTRUCTION SOON

also, does anyone know an fi email that they actually answer fast that can give me help??? i can only get through using [email protected], and that doesn't sound like tech support.

[ford302redneck 15]

14 sqin of port per cubic foot means, exactly what it says. For every cuft of your box, you should have around 14 sqin of port.

So with 6.3 cuft, you should have 88sqin.

Which your very close with 90sqin.

I'd keep what you have, it looks good to me.