Depends on the tweeter. If it has a lip, you want a matching lip. Each tweeter mounts differently. Looks good. It would be nice to see a bit more surface area around the tweeter. I have some paper mâché eggs that I will experiment with also.
imagine a laser beam coming out of the center of a tweeter (or speaker). that is the axis. you are on the axis (tweeter pointed at you) it is on-axis. if you are not (tweeter pointed away from you) you are said to be off-axis. being off-axis should be further clarified with an angle (in degrees) with 90 degrees being perpendicular. this factors into the polar response of the speaker/tweeter at each frequency. polar plots are useful in determining what you will hear as you move from being in front of a speaker/tweeter to what you hear when it is pointed away from you.
attenuate is just a fancy word for "turn it down". decrease level/volume of the nearest tweeter and the sound stage will become more centered (since we localize sounds above 3kHz based on intensity (volume) and not on pathlength).
thanks for asking for clarification. i'm sure it will help other as well.
Here's some well overdue pics of the spheres KHA made for. Fortunately, I had the same tweeters as him, so measurements were easy! I just had to give him angles.
@keep_hope_alive; is the goal to have the paths cross at a certain point in the vehicle? Part of the reason I ask is that 2 of the vehicles I am thinking of doing this on are pickups, so no c pillar to aim at. I know I can just guesstimate, and am probably over thinking it.