Aren't passive radiators out of phase?

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

Sean (or anybody knowledgable about such things),

At what cabinet size and/or radiator size does hysteresis become an issue? I would think that in a big cabinet or with a big passive radiator, the response of the radiator to movement of the active would begin to lag, resulting in some potentially smeary sound. Is this an issue? Inquiring minds wanna know these things....

will

I've never spent much time playing with or learning about passive's although i have owned a pair or two over the years. As you probably know from some of my posts, i am a "sealed" kinda guy when it comes to boxes with TL's coming in second. Someone that is far more knowledgable in this area would have to help you out.

All i can say is that passive's allow a lower percentage of "out of phase" signal to play with speakers reproduction above its point of resonance than what a port or simple "slot loading" allows. Below the point of resonance, they are all about equal. Sean
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