YouTube subscriber Ann made an inquiry about how she could learn to speak louder and deeper. Here's a quick run at the basics of breath support. You need breath support (abs!) to speak louder, and these exercises will usually lead people to speak with a deeper voice, too.
Just like most things, this isn't an instant permanent fix. It does require that you continue to practice feeling this additional resonance and work in your abs, but it can transform your voice if you work at it!
Let me know if you've got a question!