View Full Version : ...enclosure fi q18 Q...

02-10-2009, 12:38 PM
i've already asked it many time, but since i had few weeks to play with the sub, i just can't love it as much as i tought i would.
My car won't let my use anything bigger, i even had to cut more than expected... at 8ft/cu the sub was def sounding deeper, lower and louder in my house than what i got now in my car (6.5net 30hz).
It does hit the low, but now the same way it hit those with more airspace that was so much nicer :( my dog and cat, they were both scared as **** wondering what the fock is going on :laugh: )

In powering it with a bxi2006d, i know it ain't a sq amp but still... It does it the 30-45 quite well but there's a huge dropout after that.. is it normal? my old alpine type r were a lot tigher in the 50-80hz freqs...
it does is loud, maybe a lil less than what i was expecting...

So i'm thinking of going sealed. It will require my to get the box out ... which is not cool atm... and work a little on it. I would be more in the "optimal" fi audio recommended range of airspace but will i loose a lot of dbs? I already find it is hitting low enough.. so not a lower end problem
I mean, right now i'm on the lowest ported airspace and if I mod my box i'll be in the higher of the recommanded seal airspace... what can i expect? sq and spl wise?

02-10-2009, 12:41 PM
mainly listening to rap btw... and no i don't want to switch for a bl or any other sub... i'll keep this one for a while

winsd someone?

02-10-2009, 02:48 PM
so no opinion on biggest sealed box/ smallest ported possible?

02-11-2009, 10:38 AM

02-11-2009, 07:44 PM
no one experiment enclosure size with fi q?
The sub ain't sounding that good, in particular over 50hz... it's a real deception for now :(

Jeremy M
02-11-2009, 08:07 PM
fi q isn't made to hit any upper freq.
u should try stuffing your 6.5cu ft box...and that should get u just over 7cu ft....but the Q was made for SQ, so where it rolls off your mids are supposed to pick up.

02-11-2009, 08:11 PM
yeah i might be trying polyfil, but i'm gonna need a shitload of it :D and i don't thing it work that much in a such big ported box...
The transition between line seems.. awkard sometime, the box ain't got air leak but no bracing either... do you thing bracing could get me some more dbz??? any bracing i could add now that the box is done?

check his Q http://www.youtube.com/watch?v=pbrRGdU9qgk Sounding so much more like when i had mine in 8ft/cu... even if it's a youtube vid, that give an idea...
**** little accent

02-12-2009, 11:23 PM

02-13-2009, 04:24 PM
double post but i'm deleting the first one

02-13-2009, 04:26 PM
thank's for the pms Snb778,
Anyone else got some experience with fi Q18 in different enclosure volume?

02-14-2009, 01:00 AM
Do the biggest sealed box possible, and completely stuff it with polyfill.

02-14-2009, 01:16 AM
Thats weird, i used to run 2 18" Q's and they would MURDER the lows. I was at about 10^3 and 35hz. If you go sealed you are going to lose a bit of output, if i were you i would try building another ported box. Personally it seemed like the Qs had more low end than the BTL's but i am going to build a new box for the BTL's and try to give them a little more air and a lower fequency.

EDIT- I just realized your lacking the upper end, not lower end. That is something i noticed to, they were not very loud over 30-40 hz but it could also have to do with the low tuning.

02-26-2009, 11:24 AM
I've mod the box but I ain't sure i've got enough port area....
box before displacement = 7.1 ft/cu.
three 4inch diameter aero x 9 inch long ( ain't big at all but i wanted a 35hz tuning)

The sub does sound more present than at 30hz but not really louder... is it because i ain't got enough of aero port area?

02-26-2009, 03:55 PM
well after some more playing time... it does is louder :D it hit higher and the lows aren't that bad either... they were just a little better with a 5hz tuning lower