L7 in huge box- what port ?

[srool]

Hello,

A friend of mine has 12" Kicker L7 and Mac Audio Fearless monoblock that is rated 900RMS and probably gives much less (pretty overrated).

He stupidly built a huge box (around 5.5 cu.ft) for it, and doesn't have the money to build a new one.

He wanted to know what dimensions of Aeroport would be good for him.

He wanted to tune to 30 hz so I suggested two 6"x27.5" round ports for this, but other friens claimed that there won't be enough air pressure.

As I calculated the port area per cuft it comes out around 11 sq.in per 1 cu.ft.

Can someone please explain me how the difference stands out between this case and recommended volume tuning?

Is this safew to run it in this box?

Would it be effective ?

What would you recommend him for the port dimensions?

Thanks !

[john253a]

what are the box dimensions

and if it is that big just put another sub in there but if he dont have the money run the sub in series on all coils to give it the lowest rms possible off that amp

and for aero 2x6" 20" long is 33hz,

but idd tune it a lot higher in that box as the size will still let it get low

idd go 2x6" 10-15" long

another thing he can do is what ever wood he has left over make another box and put it inside of this box to reduce the air volume inside

[srool]

The box inner dimensions are:

Width 32.3"

Hight 15"

Top depth 15"

Bottom bepth 18.1"

It comes out around 5.8 cuft before displacement of sub and ports.

if tuning higher- is it ok to go with 3 6" ports and gain more port area or is it harmful ?

[john253a]

im getting 4.64 gross

i take it as he has next to no money it will just be pvc port yes, thats no probs

either 4x4" ports (front to back at bottom) 15" long @ 40hz 3.95net

or if you side port

4x4" 20" long 37hz 3.8 net

4x4" 24" long 35hx 3.6net (this is what i would do)

4x4" 28" long 34hz 3.5net

2x6" 15"long 42hz 3.9net

1x8" 24"long 35hz 3.7net

[srool]

Thanks, I calculated the outer dimensions therefore the differences.

I think I'd consult him to go with the 4 4"s or 2 6"s.

[Hugh G. Rection]

He stupidly built a huge box (around 5.5 cu.ft) for it,

i dont see whats so big about it. i ran a solo-x 12 in a 6.5ft^3 enclosure and could bass race over a 150 with it..... won nopi nationals and 4th at the 2006 bass race world finals with it..........