Subwoofers in a 2 Channel System

I have a Focal Sopra 3 system powered by a Gryphon Diablo 300 along with two JL Audio F112s crossed over at 45 hz filling in the bottom end(one for each channel).   The other day I powered up the system and settled in to listen to music for a couple of hours when I noticed that something was really off.   I couldn't put my finger on it...   

Come to find out...a few days earlier I had unplugged my entire system due to lightning.   When I plugged it back in I had forgot to plug back in one of the subwoofers.   I felt like an idiot.   What surprised me the most about this little unintentional experiment is that it was not so much the lack of low end bass, but the soundstage depth.   As soon as I plugged back in the other subwoofer the soundstage placement and depth really improved dramatically!

Anyway, it was a surprise and thought I would share.   Happy listening!