.put on some music you like, i suggest you start off with your sub off. this way you hear just "mids/tweets". go into the crossover settings. set the slopes to 24 then set the front and rear high pass to 100 listen, then change to 90 listen then 80 listen. after listening to the diff frequency settings, set it to the one that sounds "best". You might also find that your front and rear like to be crossed over at different frequencies. Once you feel it sounds good it is time to dial in the sub. put music back on, I would start off with the low pass at 80 with 24 db slope. if you set your high pass to 100 then try 90 for low pass and then try 90 then 80. see what sounds best/ blends with your factory mids/tweets. (this step assumes your sub amp gains are already set. if you need to set your sub amp gain there are a number of ways to do this).