Aren't passive radiators out of phase?

The drivers of most speakers except for Meadowlark, Vandersteen and a coupl of others are out of phase due to the high order crossovers most commonly used.

Passive radiators have to be out of phase but drivers can be wired to make them in phase to compensate for the crossover.

No, no, no, most speakers with higher order, i.e. 3rd order and above, crossovers do not deploy the drivers in opposite phase as they did fifteen years ago or so. A quick scan of the Audio and Stereophile test reports of the last fifteen years will clearly show this. This is not to imply that they are phase coherent, higher order crossovers are not. A passive radiator is modeled the same as a vent in a reflex enclosure, the maximum output of the passive radiator or vent is at the minimum motion point of the woofer.

Besides the phase considerations, you should look at the transient response of all vented designs. Passive radiators are the slowest of the slow but can still sound "good" if done right. I much prefer a well tuned passive radiator to that of a port for multiple reasons. Sean
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I don't understand the nature of the question, other than your possible concern of buying a speaker which you find inferior, due to a passive radiator inegration.
I personally owned Thiel 2.3's, that used Passive radiator, and the things were fantastic sounding from top to bottom!
I do tend to notice, however, that my favorite subwoofer designs DON'T employ passive woofers! Hummmmm...beyond me