I suppose a good place to start is to ask yourself: what does Respect look like to you?
If a band respects you, if the students respect you, how would you know?
Next question: Do you model that respectful behavior to them? If you want it from them, you need to give it to them as well.
Followed by: Do you hold them accountable for their actions? Are your expectations of them clear and understandable?

For example: I know of a very successful retired director whose band students still respect him and admire his accomplishments. He was very clear about how he expected you to come in to his band hall. If you didn't, he would calmly tell you to go back outside and come back in quietly. He wasn't rude, he just expected you to comply. And he himself would also enter the band area in a calm and collected manner. He didn't allow students to talk while he was directing, and would stop the group and tell them to stop talking, that their conversation was louder than the students who were playing, and he was trying to hear the musicians to help correct their playing. But, he was mindful of the fact that some students have the attention span of a flea on caffeine, and would limit the times he stopped the band, and would limit the number of words he used so the kids spent more time playing and less time sitting. And he knew they needed to let off some steam here and there and would allow them to talk once he was off the podium.

Again: You want "more respect" from your students. How does that look like? Are you modeling and are you holding them accountable for their actions?

Good luck. There are no easy answers.