2 m3's may be an idea in the right direction. I think you need the larger drivers in the center to produce the tones correctly.

I tend to think a problem may be using a stock or on-hand driver to create every speaker in a manufacturer’s lineup may be a problem. I'm not so sure that you would want an aluminum cone to reproduce vocal qualities. It may indeed not be the material necessary to get a pure reproduction on a center channel. I understand manufacturing costs and more inventories but it may be necessary.

Just a thought……