Aren't passive radiators out of phase?


Passive radiators seem like a great idea, but they must be out of phase with the driver. Yet, you see them on some pretty good speakers, such as the Sunfire subs. All I can think is they provide a spring-board, storing energy for the driver. Still, any sound produced by the PR is out of phase though. Any thoughts?
jhimnsue
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
>
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
>
The dual 18" PR's in my HT SW really only kick in at very low frequency i.e. sub 30 HZ. Off the top of my head they each have a mass of around 1500 to 1800 grams. This is about 3.5 pounds. At these low frequencies the 15 inch driver's main job is to drive the PR's, not to produce direct radiated sound.

My 18" music SW is a 7.5 cu foot sealed box which I augment with a BASSIS. This avoids any potential problem with ports or PR's.