12 inch sub(JBL) in box with a 500 watt pioneer amp, sounds good with some types of base. would you cut a port hole in speaker box?
riverray1969 it would help if I knew the exact model number of that JBL sub you are referring to. With that info I can provide exact specs.
Basically, you need to build/modify an sub enclosure that is suited for the sub, the music you mainly play, and vehicle tuning. Generally, sealed enclosures will provide tighter bass response and get decently loud. Some would argue that it will give you greater sound quality. A ported enclosure will give you a louder more booming sound. That depends also on where the port is tuned (ex. 32 hz, 36 hz, etc ). You need to make sure that the enclosure meets the sub's airspace requirement as well. A customized well made enclosure is just as important as the sub you put in it.