needing some help

[1loudZ71]

im needing some help find out what my box size is and what its tuned too.. i also what your guys input on the right size box for my subs and truck.. the system is only loud or some good with the windows down if you roll them up the subs sound bad and dont wanna move.. so i wanted to know if its the box or if its just to much air wit the windows up before i go adding 2 more sub and making it worst or something.. the setup is 2 l5 15's off a 2500.1 the plan is to add two more and two 1000 watt amps but i want to know how it will work to gather cuz i dont want it to sound even more like **** with the windows up.. the box is custom and big just not sure

[akheathen]

well, what truck do you have them in, and box/port dimensions. i would not go more than 1-2 l-series 15's in a truck cab, and i doubt you can even feed that single 2500.1, unless you have serious electrical upgrades, like 250-300a alt and a couple good batteries, plus enough power cable..... yes, it's going to change a bit with the cabbin sealed, but a huge difference is all in tuning. last single cab mini, i tuned it the other way around- louder with sealed cabbin.

[1loudZ71]

its a 2002 silverado 1500 ex cab with dual altr 2 batterys 1 run of 0 gauge big 3.. box is around 23tall 23 1/2 deep and 49 wide and port is like 16/12 long 3 wide and 15 deep so i guess something like 5.3 ch tuned to 34-35hz? im looking for daily but lots of flex and good lows

[akheathen]

that's a little on the small size for one port for 1 sub @ 5.3cu. i would shoot for 12sq-in per cu-ft and 36-37hz.... which direction is the port? also, check for voltage drop on that single run of cable. i would be @ 2/0, or 2 runs of what you have optimally