I have been thinking about building an spl system something i could compete with in memory of cousin who passed away in October from cancer it was a project we talked about doing before he passed i just need some tips on building a box never done it before but its a project I want to take on myself i was thinking about kicker L7 15s in maybe a blazer or a Tahoe i would assume each sub needs its own chamber and was thinking about fireing the subs up with a slot port towards the back of the vehicle my biggest question is on tuning the port o know i can't jusy cut a hole in the box and call it a port is there any apps or websites that could give me box design ideas and also another question is the best sealant for the joints thanks for any advice