To quote from issue 67 of TAS"a pair of(Classe) DR 8's sends 350 watts into 8 ohms,and 525 into 4 ohms"So I think my Classe DR 8's run in balanced mono are quite up to the task of driving my CLS even as a single run. Now when the amp sees the series set up the power output would drop some, but the increased wave launch from the extra panels makes watts a moote point and the amp sees an even more friendly speaker impedence.Forget the Speltz auto formers,not needed.I hate to beat this thing to death but I am the guy who lived with these without the sub, then with the Depth and now doubled up pair.The difference is amazing and the 80% acceptance factor goes up another 10% at least.The only time this makes sense is when you do it. Then you will insert your foot in your nether regions for not doing this before,and for trying all the "audiophile approved"expensive fixes.I am stating, you will never get a cone sub to mate with a stat.The closest the Quad 63 got was the Gradient dipole and it was not perfection.The Depth is a good sub ,I have one remember,but it is not a panacea for this or any other stat.Stats need planar bass panels to keep the music coherent.This is much more serious yet it appears not to mater to the naysayers here,who have not tried or heard a double pair,and have had little exposure to very many stats as is evident from the threads.There are NO Cancellation or Phase problems!The speakers disappear,it is a seamless integration,coherent,more music occupies the room, yet they aren't louder.More bass is present- not louder, deeper,out of phase,added on bass, but the true panel bass of a single CLS is increased. There is the same bass sound, but more of the room is filled by it so you don't notice that the speaker is bass shy.I have run out of ways to explain the benefits of a double CLS set up,and if I were wealthy enough I would fly the doubters here for a listen, because you have to hear the improvement for yourselves.