The tone of your voice is not the only thing that others pick up on. It's also how the use of pauses and emphasis that completes your speaking voice - and the point you get across.
There are a few powerful tricks you can use when speaking to instantly make your voice sound more commanding and confident.
First, learn to use pauses. They grasp the listener's attention. The words following the pause instantly sound more important. Next, know how to use emphasis correctly. The last word before each pause should be the one you are trying to emphasize. Taken to the extreme this can make you sound angry, but done the right way, it adds an awesome amount of power to your words.