Originally Posted by DigitalGriffin
You're right there. I had a morning brain lapse. :-D I already deleted it before your post when I realized my mistake. I knew better than that. I knew they had to be 180 out of phase, but reversed the image in my head when I typed it out.
But I still didn't understand your previous post. Although from what I understand these Polk LSiF/X do have a left/right side labeled on the back of them near the serial number. Like I said, I never seen a setup like this before. Its unconventional for a dipole/bipole mixed design.
Only the speakers pointing directly at the listeners head should be firing in bipole mode.
I would imagine all speakers would fire in dipole mode.
Not really unusual. These Polks are not the first dynamic driver, box surround speakers to offer both. There's usually a simple switch built into such a design that allows you to flip the phase on one set of drivers in each box 180 degrees to create a bipole or dipole as you wish. Once set to dipole mode, you just have to make sure you've got them mirrored correctly to avoid nulls.
I wish I knew how to upload a sketch. You'd get it instantly from a picture.
Planar speakers like my Maggies on the other hand are natural dipoles. When the front side is generating positive pressure the back side must generate negative pressure and vice versa. Dipoles can be very useful in a real world room. The back wave can provide a sense of space with 2 channel material and the nulls at the left and right side can minimize room boundary interactions with adjacent walls.
Definitive Technology has made a living out of bipole only main L/R box speakers with dynamic drivers as have many other speaker companies dating back to at least the 70's.
And then there's surrounds like mine that don't fit any of these categories but are also set up as a mirror image pair. But I'm too lazy to go into that description.