Fi Q18 enclosure...

[xprime4 5]

Hello , Fi community

I got my fi Q 18inch a month ago. I had some time to play with it.... hooked on a bxi2006d @1ohm

Right now, it's in a 6.5 net enclosure tuned to 30hz with three 4x15 inch aeros. It hit the 35-40hz freq nicely, but i'm sure i can get more out of it.

This summer, i'll be might be working on a way to use my wheel pit and get another 2ft/cu maybe. How will the increase enclosure volume help the Q, i mean in loudness and sq.

I'm thinking i might get more prononced 30-40hz range, is that accurated? how much louder? is it worth the trouble fiberglassing the wheel pit???

Also, the 55-80hz range ain't loud at all, is it normal? i mean my old alpine type r were quite loud in that range, the Q is another story

the hpf is at 80hz atm, should i put it at 60hz even if my comps aren't going that low?

thanks in advance

Edited February 13, 2009 by xprime4

[xprime4 5]

oh and btw, do you think the sub has totaly broken in with around 30min per day x 30 days? Most of the time with a lot of power, i mean can i expect more loudness over time?

Edited February 13, 2009 by xprime4

[ABXX49 20]

Sub should be broken in. What does your front stage look like?

[xprime4 5]

Sub should be broken in. What does your front stage look like?

Image dynamics ctx65cs, hpf set around 90hz. Sending over 200watt to them so i can't really go lower without distortion

[aznboi3644 2]

bigger you go and lower you tune you lose out on the higher bass like you are saying lacks.

[xprime4 5]

so there's nothing to do over 60hz with that woofer? What if i tune to box a little higher and I add 2.0ft of volume?

[lee 2]

if you want higher, chop the port length some, this will tune higher. youll gain net volume aswell

[xprime4 5]

will the box volume increase will get me better lows even with a little higher tuning?

[johnecon2001 82]

It's a subwoofer.. if you're lacking higher MIDbass, look to upgrading your front stage and deadening.

[xprime4 5]

It's a subwoofer.. if you're lacking higher MIDbass, look to upgrading your front stage and deadening.

I already got great midbass from my image dynamics ctd65cs. Still they won't go down to 60hz on 300watt rms. Every other sub i tried had descent response till around 80hz.....

q

[crazyder 0]

Why in the world are you sending 300 watts to something that only recommends 100 watts? That is probably why they are distorting.

How sealed are your doors?

Johnecohn2001 is right you are asking about midbass, despite what your previous subs did, anything over 65hz your subs should not be the key to.

[aznboi3644 2]

18 inch sub...my 19Ov.2 rolled off around 60Hz...big cone has a high end roll off i guess.

You might say you have enough midbass but you wouldn't be complaining if you DID HAVE ENOUGH MIDBASS.

[xprime4 5]

well midbass to me is 80-400hz. 40-80 is bass and under that subbass....

it just seems like there's a empty gap between the two. All the woofers I had prior were 12inch. They had no problem getting up to 80hz without rolling off, but weren't as strong in the low as the fiQ18 is. I tought that sub was pretty linear from 30-80hz but it ain't the case. Minsinformation i guess....

But what are the benefit of building a box that is bigger? fi recommand 6-10 and i'm at 6.5. what if i go to 8.5, how would it change the sound quality and loudness of the sub?

My door are deadned, but i'm getting mad window vibration setting my hpf under 80hz btw

[lee 2]

yes the 18Q digs deep, and it seems you dont like it. like i said earlier tune higher, you'll reach the gap you're speaking of, but sacrifice your 20hz range output.

you might be 1 of those 40hz tune daily guys idk

EDIT: if the above is true, the Qs not for you

[aznboi3644 2]

dampening the doors will help a TON with midbass.

Also there is nothing wrong with sending 300 watts to 100 watt speakers.

My 6x8s are only 40 watts rms but they have been taking 80 watts rms for the past year no problems.

[xprime4 5]

i'm thinking about modding this box to achieve a 35hz tuning. I know this ain,t what fi recommand, but should it? Can i expect a higher dropoff and some more db's...

[dbjunior 0]

i think you would be better off switching to a bl it would fit your desires better. i have a q18 and have tried a lot of boxes you wont get much in the 60-80hz range its made to do great on the lows and it does.

[xprime4 5]

i'm about to tune that box to 35hz. what can i expect? wider ranger in the upper bass + a little more spl?

[lee 2]

yes, a little. give it a try

[aznboi3644 2]

If you want more upper bass make a smaller enclosure tuned 35-40Hz

[xprime4 5]

If you want more upper bass make a smaller enclosure tuned 35-40Hz

smaller? its already the smallest size fi recommand

[Solid_State13 1]

the bigger your box, the larger the peak at tuning, so if you have a smaller box, when you tune high it wont be as peaky

[aznboi3644 2]

large enclosure and low tuning it lacks on the upper bass frequencies...going smaller will not affect the sub in any negative way if you are afraid of blowing it. The only thing that will happen is the mechanical power handling will go up.

[xprime4 5]

large enclosure and low tuning it lacks on the upper bass frequencies...going smaller will not affect the sub in any negative way if you are afraid of blowing it. The only thing that will happen is the mechanical power handling will go up.

ok then , next step will be increasing the tuning and if it doesn't help me out, i'll be making a smaller for it

thanks for the help dude