Abhi, since you have an excellent sub in the VTF-2, the lack of mid and low bass in the M2s wouldn't be a factor and three of them across the front should do very well. As to the surrounds, it's a question of how direct or how diffuse you want the surround material. Since you're already using a QS4 as a back surround, if you like it there you probably would like two of them as side surrounds even more.

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Enjoy the music, not the equipment.