It seems to me that above the fronts would likely be the best place for "height" channels. However, I am all bent out of shape about loosing the center channel, which I have always considered most important, even for stereo, where it is easily derived from ther 2-channel source.
I don't know why the center channel speaker gets such criticism in audiophile circles. Examination of the signal characteristics of stereo recordings will show that common-mode modulation dominates, and this is center material. In particular, solo performers are usually recorded equally in both channels, and isolate nicely in the center channel. I know that two good speakers will image the soloist between them, but this effect depends stronly on listener position, which is not the case where a center channel speaker is used. Other advantages are a wider soundstage because the left and right speakers can be further apart, and reduced speaker power for a given room sound volume level. Of course it goes with my philosophy that the center speaker and amplification should be as good or better than the left and right. Perhaps the minimalist center channel speakers that are commonly used for movie dialog may be responsible for the bad rap for music.
I don't know why the center channel speaker gets such criticism in audiophile circles. Examination of the signal characteristics of stereo recordings will show that common-mode modulation dominates, and this is center material. In particular, solo performers are usually recorded equally in both channels, and isolate nicely in the center channel. I know that two good speakers will image the soloist between them, but this effect depends stronly on listener position, which is not the case where a center channel speaker is used. Other advantages are a wider soundstage because the left and right speakers can be further apart, and reduced speaker power for a given room sound volume level. Of course it goes with my philosophy that the center speaker and amplification should be as good or better than the left and right. Perhaps the minimalist center channel speakers that are commonly used for movie dialog may be responsible for the bad rap for music.