Not really. The purpose of a passive radiator is similar to a vent in that it harnesses the wasted internal energy of the enclosure for additional output. They're finicky though so most people avoid them.

 

I wanted to post some charts from a book by yamaha that outlines the effects well... 'sound system reinforcment'... But I can't find it...

at anyrate a small clairification is needed.. 163hz is where refraction will start going on.... the first actual standing modes will be at 565hz....

True enough this is much more important when dealing with large cabinates and drivers reproducing higher frequencies.... but Ill guarentee that fill will help get rid of audible distortion in any scenario.....