i got a kicker l7 15 dual 4 wired to 2ohms into a hifonics brutus 1200. i just got my box built by one of my buddies who owns a shop. the box is roughly 5 cubes tuned to about 35hz pretty sure. i got everything together last night and spent all day today playing around and trying to tune it and it just does not want to put out those real lows in some songs. sounds like its just blowing air. None the less it tears apart the mid to high bass. i dont know what i could do to change it up maybe rebuild the port or something. not to good with this stuff thats why im asking you guys.

inside of box dimensions:

width 39

height 13.5

depth 18.5

its got 3 in wide slot port

its just a 10.25 piece going down it doesnt corner off or anything

you should state your crossover and filter settings (head unit and amp) to give us a starting point to help ...

What vehicle is this in?

Enclosure placement and driver orientation play more a part than most think.

you should state your crossover and filter settings (head unit and amp) to give us a starting point to help ...

hu: kenwood excelon kdc-994

sub amp: hifonics brutus bxi12100

u mean crossover and filter settings on the amp or the headunit.

on the headunit the subwoofer crossover is set at

fc:80hz

slope: -24db/0ct

phase: normal

is that what you mean?

its in a jeep cherokee. box takes up most of the back hatch aread. with sub and port firing up towards the roof

with .75 md you get 39.45 hz tuning and with 1 you get 41 hz tuning.. not including drive displacement, bracing, etc.

The Brutus has a subsonic filter. Make sure that isn't cranked all the way up to 35hz

The Brutus has a subsonic filter. Make sure that isn't cranked all the way up to 35hz

i got it at about 30

The tuning is way to high.

According to my calculations it seems as though it's not too far off from being correct, although it seems the tuning is actually about 38hz, it shouldn't cause any unloading issues, which sounds like the problem you're having. That's assuming the port is 3" wide and the 13.5" tall and that the measurements you posted are accurate and actual internal dimensions.

That being said, and again assuming the above port dimensions, the port area for that sub seems low, it may not be but it could be causing port noise if it is. Otherwise you could have an air leak that's causing the sub to unload as well.

Settings could possibly be off, but if it actually sounds like blowing or huffing air coming from it then I'd be willing to bet it's unloading, the port area is too small or a combination of both that's causing your issue.

The tuning is way to high.

alright well the hu crossover for the sub

goes on the fc:30hz to 250hz

the slope from 8 to -24db/oct

I meant for the enclosure and it seems the port area is to small

I meant for the enclosure and it seems the port area is to small

so what more like a 4 in slot port

I can't find the XMAX spec for the L7 subs ANYWHERE, even on kickers site in the owner's manual which is odd. Without I can't calculate the minimum required for the sub, however I have to imagine it would need about double the port area it has now to operate as it should. That would in turn require a larger enclosure to fit the added port displacement.

The 12 Is roughly 14mm I would assume the 15 would be around there

I can't find the XMAX spec for the L7 subs ANYWHERE, even on kickers site in the owner's manual which is odd. Without I can't calculate the minimum required for the sub, however I have to imagine it would need about double the port area it has now to operate as it should. That would in turn require a larger enclosure to fit the added port displacement.

huh well i guess is wasnt made to well. rather make a new box myself. does anyone have a plan for an l7 15 box. i want about 5 cubes and between 30-34 hz. something that willl be just shaking things around

my max dimensions i can use are 42 width x 22 depth x and 16 height

Edited January 25, 201213 yr by atrueOG