As an intersesting side point, I should mention that I hooked up the QS4s to the front channels in place of the M50s the day I got them (since I didn't have the cables, studfinder, anywhere to put the things on the sides of the couch, etc.) and listened at low volumes to make sure that all the drivers were operating. They didn't sound too bad in front. (I had them standing on one side so as not to obscure the woofer.) A bit diffuse, but not as much as I expected.

I am the Doctor, and THIS... is my SPOON!