I'm not a fan of passive radiators. They make no sense to me. If the passive diaphragm is equal to that of the woofer, then five calculations are required.
Sealed cabinet with passive radiator.
Sealed cabinet without passive radiator.
Ported cabinet.
Sealed cabinet with twin woofers.
Ported cabinet with twin woofers.
In no scenario does the passive radiator #win#.
Sealed cabinet with passive radiator.
Sealed cabinet without passive radiator.
Ported cabinet.
Sealed cabinet with twin woofers.
Ported cabinet with twin woofers.
In no scenario does the passive radiator #win#.
Ports and PRs are ultimately just cheaper alternatives to sealed. PR is more feasible in smaller cabinets when you account for volume taken by the port
To be fair... this DIY. Land of the unreasonable👽
https://www.grimmaudio.com/pro-products/pro-loudspeakers/pro-sb1/ Supposedly these guys are terrific. They use MFB. A bunch of people here recommended this as a viable design technique and so I've been looking into it. I definitely like the idea. Just need to weigh the pros and cons of each I guess.