testing db

[muffman001]

hi there i was just wondering how hard it would be to test the db im puting out in my car i have heard you need a mic and a computer i have been told you need to put the mic at ear level drivers seat and turn all eq off
but what program do i need and what else is to be done ??????
please help

wanna c the db rateing of my less than $300 system :drink: