ok first, you need to determine what the speakers are made for.. not all drivers work in both box types. you need the TS stats 9should come with the subs, or download the tech specs from their website) and calculate the EBP here's how:
Efficiency Bandwidth Product (EBP) EBP = Fs / Qes 50 or less = best used in a sealed enclosure. 50 - 90 = flexible enclosure options. 90 or greater = best used in ported enclosure.
hey mo i was just wandering, if a sub is rate at say 48, does that mean there is a smaller gap in loudness going from sealed to ported in that driver whereas if you go from sealed to ported with a driver thats 115 there is a much bigger gap?
Alex... You should do 1 15" Type R in the 4 runner... I know a guy doing 142.1 db with a 15" R in the trunk of his car. Definatly port whatever you get though... The 12"s I'd tune them more around 34hz then 38, the 15" I'd do 32hz
for the 12" subs, go with about 1.5cu ft per sub for sealed, and 2cu ft per sub if ported. ported, tune the ports to about 35Hz, using 4" inner diameter ports. (tuning the ports is done by adjusting their length. Remember to allow for speaker (and port tube volume) displacement when calculating the box dimensions for interior volume.
3cu ft per 15" sub, 6" inner diameter ports, one per chamber.