Could you stack the SP200 on top of it and show us how it stacks up? The M400 seems very deep and the SP200 would look ridiculous on top of it. How's the pairing with the SP200 by the way?
the top side of m400 looks very weak to scratch, so it is not a good thing to stack it. but yes, I think it is not fit. the size is very different. I am waiting a SP400.
however, the sound, it’s nice work. detailed, silky sound. nice deep bass but the punch is little light. depth of sound stage is good, but width is not wide for me.