First, while it is not ideal, don't let everyone scare you. I, too, had to convert my set-up from vertical M22s to horizontal. They are wall mounted about 7 ft high.
pmbuko gave you good advice, which Alan also gave, and that is that you want the tweeters towards each other.
The sound is not ideal, but I have to say that angled downward, and slightly toed it (for my set up), the sound is still outstanding. Since mine are near the ceiling, the bass gets some extra reinforcement, and I need to recalibrate for the room.
But overall I am pretty pleased, and you can still get great results.
Rich
