Center channel height for 3 ch stereo

[profsbg]

Considering a center channel between two Khorns spaced about 17'.
Due to projection screen only have about 30" max height below screen
for center channel speaker. Mostly will be used for 3 channel stereo,
but will serve double duty as HT center channel.

Am somewhat
confused about center channel height (for 3 channel stereo). Most
suggest same height as tweeter/mids in mains. If so why are LaScala
Belle Cornwall significantly shorter than Khorn which they were center
channel for originally (like 15" shorter, although not sure of exactl
tweeter/mid heights there)? Were they intended to be used on stands?

The
only thing that seems workable without replacing screen is a
Heresy on a stand (10" stand maybe). Does anyone have experience
using Heresy with riser or other angling either on floor or short stand
as center channel for 3 channel stereo between Khorns?

Thanks.