THis is directly related to gaining up to 10 - 15 db in your system, i know to find out your cars resonance freq in hz u can either do the 1/2 sin wave or 1/4 sine wave experiment... where u calculate the # of feet from the back of your car to where you feet rest and so its 1138/that number/4 or 2 depending on 1/4 or 1/2 test... 1/4 is more spl 1/2 is more street i think 1138 is speed of sound in feet... now im wonderin if anyone has already tested the freq of a maxima 4th genreation by puttin in a sealed test box and a metre to see which freq gives best spl...... anyone done it ??? im goin for 1 15 dd 9515 sub which shoudl give 155 db if i do it right off of one dei 1100d amp and a capacitor as well as an extra car battery for the amp. LEMME KNOW

 

most cars have a resonant frequency around 50-55, but if you wanna find it yourself, take a sub and use an rta to find the peaks of it in an anechoic chamber (or in an open field or something), and then test the same sub in the same box in car. then the peak between 50-55 hz, that doesnt match up between the 2 is the peak for your car.

eric

 

i've done that in my sentra before..it does work i did it while i was at installer institiute in long beach. We did the SPL test and everything i used a RFosgate HX2 in several boxes...the spl meter showed a difference of about 7 db difference with the various sealed boxees.

 

how are you planning on pointing your box? and what size box you usin?

eric

 

ported box the ports on the same plane as subs firing towards trunk.... first i thought i would have the port firing through the middle of the seats at the back but its not good to have subs and ports on different plane... the size will be about 4-5 ft^3 what do u think?

 

sounds about right.

eric