Here are a couple of designs I did for boomnblzr from ca.com... not a member here yet, but hopefully soon
First is for a pair of 8" RL-i.... 1.3cf @ 33Hz, 21 sq in of port area, going into an S10 Blazer
Second one is for a quartet of 10" RE SE's... 5cf @ 34Hz IIRC, 70 sq in of port area, for the back of a Tahoe
pics:
