As a lifelong musician, that has been on stage hundreds of times, I have never had any problem with projecting my presence to my students. I have a deep, loud voice that has no problem in being heard and I have a sense of humor that is projected into the class setting. I find it puts the students at ease, and takes the idea that this is a chore away from them. If they have a little laughter while learning, they will pay better attention, is what I have found over the years.