What kind of Box you sugest for 2x Pioneer 307D2 just for SPL Street B class.

Dimensions, Port, and other things.

Thank`s

Something tuned to your cars response.

My car is WV Golf II

How to know what is my car response? How to measure that?

easist way..grab a termlab, place the mic in the location (or real close) to where the mic will be in competition. grab a sealed box and install your subs in it. add your power and play a sweep. write down the frequency the car played it's loudest. recharge the battery(s). start 5-7 cycles down from the seeep peak and burp the system one cycle at a time till you see the score go down. write down what the peak was. you are now real close to the car's peak frequency response. build your box anywhere from 7 to 11 cycles down from that peak and test...

it's not an exact science, but will put you in the ballpark. you have to remeber, seat placement, mic placement, battery voltage, box placement and overall size, will all affect the score. after you find a general peak, start testing until you just don't get any louder.

and then test, test, and test some more.

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

A wild guess on the golf would be maybe 49hz.

Yes Denim that is correct . Today I mesure and loudest frekvency is 48-49 Hz! What i need to do next? How to calculate a dimensions of box, port lenght?