Hey Austinbirdman, I had the exact same thought some time ago.
I wanted to use two M2's since after reading a post here linking to an article explaining why a horizontally placed speaker isn't very good ( can't find the link) I really don't believe the horizontal dispersion of any centre channel ( or any horizontally placed speaker ) can be as good as a vertically placed speaker. As well I'm interested in using DVD-A / SACD and certainly the recommendation for that is the same speakers all around.
Can you do as you suggest? I'd say yes and you'd want to connect them in parallel with a resultant impedance of 4 Ohmns ( 1/8 + 1/8 = 2/8 --> 4 Ohms ). So you'd need a decent reciever to do this...
One caveat. Using two separate speakers together could have its own problems. Remember you're not talking a stereo signal here, but a mono centre channel. As a result both speakers would be producing the exact same sound and it would be easy to create nodes and nulls if your placement isn't done very carefully. As a result I'd consider just one vertical speaker like the M22.
I think Ians' point is well taken here; however. Certainly an identical speaker to the L/R is the optimum but for most of us placement of an identical speaker in the centre is problematic and any benefit is likely lost by a compromised placement. Thus we have the centre channel. A compromise yes, but I do believe good companies like Axiom don't just make a vertical speaker and place it on its side. Good companies like we have here will actually put effort into designing a centre that performs as close to optimum as possible, given its placement and orientation, and by every account people here love their VP150's. In my estimation if you can place a centre channel just like your L/R channel then go for an identical speaker or something like the M22, if you can't then likely a dedicated centre is going to get you the closest to the optimum. Ultimately the choice is yours and you wont go wrong no matter what your choice.
Good Luck Jane.
