all VR speakers emply this.
the cool part about it is that its not simply a rear fireing tweater.
its also out of phase, giving you a very wide/deep sence of space. Its not ugly at all.
As im sure you've read, the deal w/this is to act like a microhone in reverse. that rear ambiece, which is OOP, is exactly like a mic works. There isn't much that is picked up from behind a card or hyper, but there is some...and that is vastly responcible for certain soundstage information. So, it *had* to be included on playback, and that is why Albert went with this design.
IMO, it makes blumlein recordings sound absolutely real. A couple that I have made display rear info so well, i'd swear there were crowds of rude people chatting away behind my couch...but there is only a wall there.
I keep it cranked on my VR4, and have noticed that there is not nearly the amount of output on these as there were on my VR2s, which I also kept cranked.
I would turn them off...run for a month, then turn them back on and see where i liked it. I think 75% was where I settled w/the vr2