Over the years, I have tried numerous positions for my center channels and quite frankly, the speaker position in your particular set-up well below the monitor and in this case, inside a cabinet, when it came to performance, especially in the case of openness of sound, for me, was always the least appealing. Despite all my experimentation, the speaker, directly above the set tilted towards the listener, always turned out to be the best position.
A topic that has been discussed many times on this forum is that unless one has the space and ability to purchase a "full range" center speaker like the VP180, the consensus of opinion among many forum members is that a pair of M2s or an M3 used as a center channel will give you a somewhat more natural and better off-axis performance than a VP150.
In your case, the monitor is quite close to the wall so you could actually purchase an on-wall version of the M2 or M3 OR better yet, buy one or two of the brackets, mounting them on the wall directly above the television and tilting them toward the sweet spot. Balanced properly, this would give you a nice arc of sound between the L/C/R speakers.
