so i bought my xb gen 1 a week ago, it came with 8" rockford subs, my friend told me that i could buy or build a new box to make them sound better, does anyone have any ideas for the dimensions that i should be looking at?

 

What is the model of that sub? Just take a look at their website for the recommended cubic feet required for that sub, and make your box based on that. Make sure to account for displacement if you're really **** about getting it right lol