I found this in a different thread, but the sub they were talking about was a HDC4 12.
"As for the port area, aeros are great, but not if you cant get enough port area. AQ LOVES alot of port area. AQ suggests 16-18 sq inches of port per cube for loud daily applications. I personally stretch that to 18-20 sq inches per cube for loud daily, and 20-22 sq inches per cube for burps. A single 6 inch aero works out to be 6.25 sq inches per cube, and an 8 inch equals 12.5 sq inch per cube. Ive tried small port setups with AQ. Output will suck, and the sub (esp on high power), will not like you at all. "