but if the mains are elevated and flush mounted in a control room, at a height of say, 6 feet or so, then what would the vertical angle need to be? Does this need to be calculated so that the "focal point" of the mains align in the vertical as well as the horizontal? [/B]
There are many theories on the vertical issue, however I firmly believe the best starting point is level, especially for nearfields. If you sit in your mixing chair, and measure the height your ears are from the floor, thats the height of the center point of the monitor source points.
The sourcepoint of a monitor is 1/2 the distance between the woofer and tweeter centerpoints, along that same line, not necessarily the center of the speaker box itself. Then you can adjust up, or down, to achieve the best sound within the acoustical properties of your room.
Flushmounts in larger studios often have large monitors (say, Genelic <G>) horizontally the same as you have already figured out, but they sit much higher than level to your ears. Typically, this angle is somewhere between 5 and 8 degrees.
The reason for this is multiple, and usual has more to do with construction than mathematics:
The control room window is in the way for ear-height flushmounted monitors.
By having a slight downward angle, the reflections in the room change drastically, as there would be less standing waves. The sound moves towards the back of the room, but slightly downward thus when it hits the floor it bounced off the back wall also on an angle, thus moves up and down.
This of course can create more interesting acoustical problems, but thats another story.
The way your ears work mechanically, you have significantly more sensitivity to horizontally located sounds (stereo imaging) as compared to vertically located sounds, so a 0-10 degree incline (from your ears forward) or decline is not going to impact your acoustical response all that much.
In fact, due to "cramp" in my control room, my nearfields are mounted at just above waist level, aimed up at my ears, matching the 30/30 horizontal angles you mentioned earlier.
Actually, I'm going to move them away from me, as when mixing at the decibel level I need to use to get the flattest response, I can hear the woofers breathing which causes my hair on my neck to stand up
Did that help you at all, or did I just make it more confusing?
