[Me]

Can someone help me understand the phasing of a passive radiator?  I know that the passive is in phase with the, let's say midwoofer.  If the midwoofer is crossed over at 2.5khz, then will the passive be in phase all the way up to that frequency, or does it only stay in phase up to a certain frequency (say around 80hz), then does it go out of phase?  If the latter is the case, then will it adversely affect the midrange because one driver is moving out while the other is moving in?

[milford3]

This article will help:

http://www.humanspeakers.com/whatis/PR.htm

[Æ]

A passive radiator is just a substitute for a reflex port. It is still a bass reflex component, part of a bass reflex alignment.
A port is technically a Helmholtz radiator. You tune a port (very basic) by changing its length, you tune a passive radiator by changing its mass. Passive radiators tend to be opaque when it comes to midrange frequencies.

http://en.wikipedia.org/wiki/Passive_radiator_(speaker)

[Me]

Alright, thanks guys.  Both of those articles are very helpful.