Protege 5 Resonant Frequency?

[BlazedGlory]

Has anybody taken the time to figure out or does anybody know what the resonant frequency of the Protege 5 is?

Just wondering...any guesses? Anyone know the resonant frequency of a similar car? (Civic Si, Matrix, Vibe, Focus...whatever)

Wondering so that I can get to work on a box for spl purposes...I want to have two boxes (this is for 2 12" Audiomobile Mass subs, 600-700 watts each). I will have a box (separate chambers) that is sealed with around 1.2 cu. ft. each. I'm trying to figure out what I should tune my spl box to though for maximum spl =).

 

[macklum]

this might help you
1/4 wave lenght low frequency limits 1132/(4X Y)= the resonance of the car where y is the longest distance in the car in feet
ie 1132/(4X10') =23.8 hz I found that at least in the sedans the car resonates at about 45HZ
Standing wave 1132 /X where x is the shortest distance in feet 1132/3 =approx 400 hz where i worked this out in my 92 sedan i found a dip at 800 HZ
Some other things the sedans do as far as sound curves are
Peeks subbass at 45hz,12 db peak in the 80-150 hz range .a dip of 12-15db at 800 hz ,a peak of about 9db around 4000 hz and a roll off starting at about 17000hz
These were the problem areas I had when I was competing in sound compititions . Hope this helps .