Hafler matrix type of home theatre / rear recovery system

I guess it is not a popular setup ?

Had to do a little research on this, not having heard of it at all.  Appears to be a precursor or pre-derivative to DS/DPL, where the difference between the front R/L speakers are fed to the rears.  Not sure how this will sound in movies (I did like DPL encoding when it was the rage), but my preference for music is to eschew any surround.

It's probably not "popular" due to the prevalence of discrete surround formats, I imagine.

Posted this a couple of years ago:

I’m just going to go at this as I’ve practiced it many times.

Normal front speaker set-up.  Take long single wire from Rt (+) to Rt rear (+).  Repeat same Lt side.  Connect both rear speaker (-) terminals with single wire.

If anyone sees this as wrong and wants to scream foul, then proceed.  As explained to me it provides out of phase material diagonally.  So Rt speaker out of phase material appears in Lt rear speaker, same with Lt speaker material.

I’m no engineer, have just set it up multiple times with success.  It broadens and deepens the soundstage.