or sealed.Wouldnt be really that great.
Best performance would be all subs on one plane, and port on a perpendicular plane.
Better off just having one port.
You may have some phase alignment issues and port unloading.
Ports usually like having a solid surface behind the opening to load better.
Actually, if thats the only way to have subs fit. You will probably have better performance from just 2 woofers.