Need help with sub box design

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[Old_Slapper]

People didn't like ported boxes because the port noise and needing a bigger box. Therefore, instead of 1-sub in a ported, they would go with 2-subs in a sealed box. The complaints were hollow sounding bass and the air turbulence sound coming from the port.

Back in 1997, I started messing with parted enclosures. This was a time when sealed boxes were the common design for SPL competitions. After sitting and listening to a ported enclosure, I realized how to fix the ported issue. The hollow sound comes from the plastic pipe reverberating the sound as it travels down the pipe. Same thing as screaming down a plastic pipe and sounding like a robot on the other end. The rushing air noise comes from a mass pressure of air trying to flow out of a small port. So, the fixes were simple. Design a port that doesn't vibrate and is large enough to allow air to flow easier. Also, it dawned on me (DUH) that sound was coming from the port, so if I made the port bigger, more sound would come out. My box design caught the attention of a few manufactures, such as Rockford Fosgate, JL Audio, and Kicker. My box designs also started to dominate the DB drags in my area. A single sub, in a ported box, out performed 3 of the same subs in a sealed enclosure. At the time, I worked at DOW Stereo in San Diego.

With that said, I would go with a large port opening that is made using, at the least, 3/4" MDF. A square port put out more sound than the slash port. Tune it around 40 hz. that will give it a really nice bump in the octives.