New build for 1 18 fi q


Silver Member
Username: Cwruck

Post Number: 168
Registered: Feb-10
hi guys i decided after taking some measurements i can throw in 1 18 into my car, it will be a tight fit but will work. the plan is to have the sub sky firing and the port firing into the cabin, not at the trunk, with previous installs this is louder in my car.. dont ask why.
for the fi q i will go with the cooling, the p chamber since its free with cooling, and the spider. the sub will be run on a sundown sae-1200d at 1 ohm so i figure i may as well add the cooling since its not expensive.
measurements, i have w-32.5 height-31 depth-15
.75 mdf and with driver displacement im sitting at 6.905 cu ft.
now for the port i read that the port area should be 5-10% of the total volume so that would mean .7 cu ft or 1210 cu inches of port area.
now is that number right? if it is thats good im good to go, but if i can go bigger than that i would like to.. maybe even up to 1800 cu in if possible.
what would you recommend as port measurements, is it ok to go with a 6 in wide port? what about length and height?
and also is polyfill a good idea to add? since fi recommends 6-10 cu ft ported with the q im on the lower end, would polyfill help? Ive read it doesnt work so well in larger enclosures.
any comments or advice is appreciated
sorry for going on and on

Silver Member
Username: Cwruck

Post Number: 172
Registered: Feb-10
anyone? i just want some confirmation to make sure i dont mess the box up, i dont have the most time in the world and i dont want to build a box and accidently do it wrong.
im excited to start running an 18" Fi Q!

Silver Member
Username: 813thumper

Tampa, FL United States

Post Number: 176
Registered: Sep-09
ok im pretty sure you cant have cubic port area. that just doesnt make sense. and do you have any idea what it is tuned to? there are alot of people on here that can help you design a box so if this is your first time you may want to ask for help.

here is my aim if you want to chat about your design: enzofreak224

Silver Member
Username: Cwruck

Post Number: 174
Registered: Feb-10
sorry dont have aim but we can email. i see you on caco ill send u a pm tomorrow with my email.
i think i meant sq in according to aq's website to my knowledge from what they were saying it was saying keep the port area or sq in to within 5-10% of the boxes total net volume which my box will actually be around 6.65 cu ft after sub displacement
so that would mean i want the port area to be at the most .665 cu ft or basically 2/3s of 1 cu ft.
well 1728 cu inches equals 1 cu ft so the way i get the number for the max port area is 1728x.665 which is 1150
with the box calculator i use i found a way to get very close to that number and have a tuning of 32 hz

does all that make sense? i might be putting things in different terms than a box builder would do, like the whole sq in thing for figuring the port is more confusing than the way i was figuring it out.

and when i do plug in all those numbers i will be around 6.0 cu ft after sub and port displacement, Fi recommends 6-10 for the q which seems like a huge box to me. but i can just barely do 6 cu ft in my trunk

Platinum Member
Username: Rovin

1 15 = 153 DBs ...Trinidad & T...

Post Number: 16348
Registered: Jul-05
« Previous Thread | Next Thread »


Shop Related Deals


Main Forums

Today's Posts

Forum Help

Follow Us