I knew a guy who made a set of subs based on the JBL 4530 design for base bins that you used to see in nightclubs and discos.

The speakers he made looked to be an exact replica, scaled down to about 1/2 to 1/3 the size. They sounded great were really efficient.

He called them "baby boomers" but I don't think anyone else called them that.

Has anyone ever seen a plan for these?