crescendo fi

Currently I have a one 15 fi sp4 in an extended cab Silverado and im looking to upgrade. Power wise I have a crescendo bc3500 to push whatever I end up getting. Here are the dimensions I can have for a box; 30 inches tall, 27 inches from the back wall to the front seats, and 56 inches from side...

Today as some of you know I was experiencing some trouble with my amp which i got all figured out. But anyway when i was testing it by free airing my sub I noticed that the volts only dropped into the high 13's instead of the normal 12's when I have it in the box. IS this normal, can someone...

So the other day I was playing my system pretty hard when the sub cut out for the first time. it came back on almost instantly so I didnt think much of it until today when everytime I roll the volume up it cuts out and will come back on and then cut out again. I have a fi sp4 15 wired down to...