fiberglass design

#1 You don't need ports. Ports suck. All they do is create more air flowing through the car, and you here all that air too. Sealed boxes are the way to go. Ask anyone. They create a more cleaner crisper sound than any other. Certified installer

if a vented enclosure is built correctly it will be more efficient above the tuning frequency and also have more output than a sealed box. as far as the hearing the air. yes that is true. you can hear the air if the edges of the port are not rounded or the bass note you are trying to play is below the tuning frequency. if you listen to rap or bass cds you need to tune it low. 90% of the boxes I build I tune to just below 30hZ. this will give room for the low bass notes down to about 25 hZ. not much music has notes below 25 hZ. but if you listen to a lot of pipe organ music you might want to go with a sealed box. I have a ported fiberglass enclosure myself for a JL 15w3 and would not ever go back to a sealed box, unless for space issues. It is in a jeep Grand Cherokee, so hearing the air would be very easy. but there is no unnecessaryair movement. I listen to a wide variety of music from scratch DJ music, to rap, to classic rock. if the amp has good control of the speaker, the crossovers and subsonic filtres are setcorrectly, and the box is built correctly, the sub bass will still be responsive and sound as it should. if you have a weak link in the system you will have issues.