Box Design Help for 18" FI Q w/BP, 4" Aero Ports...

[snb778 5,000+ posts]

15 won't give me the output I want... I can go down to 6 cu. ft. and still be within specs of FI... Keep in mind people.. there are people running FL BTL's in 4.5 cu. ft

and maniackilla... I just looked through all of the links in the sticky for enclosure design... not 1 site came even close to aero port calculations

anybody know based on the specs I posted how much port I even need... lets start there

 

[mlstrass 5,000+ posts]

Q will do fine with 12^2 per cube if doing a normal slot port and the general rule when using aero's is that you only need 1/2 of that amount. Now figure out your gross box size, account for the space the sub & aero's will take up, and see what you have to work with...

 

[terra 5,000+ posts]

I have 10 cubes for 2 18"s and I went with 8 4" ports

 

[snb778 5,000+ posts]

Q will do fine with 12^2 per cube if doing a normal slot port and the general rule when using aero's is that you only need 1/2 of that amount. Now figure out your gross box size, account for the space the sub & aero's will take up, and see what you have to work with...

I can't do that until I find out how much port I need... sub disp. is .123 i believe... again though, I dont know what this Q wants for port. This is what I would LOVE for someone to figure out for me who already knows how to figure it out. I've looked through stickies, I've search for links, i've looked at some tutorials..gave me nothing.

Im simply looking for someone to say, "ok, for THAT SUB... 6.7 cu. ft, to tune to 30Hz with 3x 4" Aero's, they would have to be ____ long, giving you xx amount of port area"

im sure there are TONS of people out here that know how to do this, I don't get why its been so difficult getting help.

 

[mlstrass 5,000+ posts]

What do you mean "how much port it needs"??? It needs 12^2 per cube of box. Pick your tuning, figure out how long they need to be, calculate how much volume they take up, etc...

It's all there for you to figure out...

 

[mlstrass 5,000+ posts]

And once you figure out how to calculate it once you'll have that knowledge going forward...

 

[snb778 5,000+ posts]

as i've said.. the reason I want to go ported is because its not loud enough for my preferances... 15 wouldn't cut it.. im already downgrading from 2 15" Type R's ported off of 3000watts... I wanted to get a smaller, better quality driver that could get just as loud... everyone was talking about their 15 flexing, and their 2 15's sealed flexin, so I was hoping this could get the job done...

6.7 is still within recommended specs.. I at least want to try it before I ditch it... know what I mean

 

[snb778 5,000+ posts]

ttt

c'mon.. theres only like 50 people on here that build boxes

 

[mlstrass 5,000+ posts]

what you want is a design and there's plenty of guys on here who do designs for a few $$$.

Otherwise just take a few hours to figure it all out as it's not that hard.

You would probably end up around 6^3net after the sub, ports, and bracing, so it should work...

 

[snb778 5,000+ posts]

MOST guys on this site want 20 bucks for a design... I already have the box design.. I just need to know how many ports I need, and how long... something that should be VERYYYY simple, and IF i knew how to do it.. I wouldn't charge people for it... seems like basic help to me...but im getting to frusterated waiting for help so I just might do that soon.. next day off is sat. i think.

 

[mlstrass 5,000+ posts]

a 6cube box needs 72^2 of port area for a Q. You need around 1/2 of that if using aero's, so 36^2. 3 4" aero's would do the trick. For a 30Hz tune they need to be 16.89" long.

Each port will take up .12^3 of space, so .36 total. Add .36 to the disp of your sub and that total is what you need to add to 6cubes for the gross box size.

Now you can spend Sat building the box...

 

[snb778 5,000+ posts]

Thank You!!!

seriously.

how do you know how much port this sub needs though, so in the future I can have that stat. ready.??

I almost want to pay you just because it was so hard to get an answer from someone, and i was probably 12hrs away from payin someone for a design anyways. PM me your email and ill send ya 5 bucks if you have paypal... im going to take the box out on fri, and actually sat. Ill prob. build some cardboard boxes to see what kind of max dims I can get... problem is I can only have itbe 14.25"tall... I've had a box 36"wide, but it was like 22" deep... so I figure i'd go a little less wide, and a little deeper to compensate.. IF possible

do you know if the less port'S=better... like 1x 10" port vs. 3x 4" ports??

 

[skadude016 5,000+ posts]

6.5 cu ft tuned to 30hz exact same tuning/box and woofer you are using.

 

[skadude016 5,000+ posts]

let me know if i can help i have all the specs for it //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[snb778 5,000+ posts]

ok, well I just went and measured my trunk... I have a little more room to work with... External Dims, I can get 7.1cu.ft. AFTER port and displ.

So that being said...how long should the ports be (im using 3) to tune to 30Hz? someone help me out here, im willing to pay for a quick answer