When it comes to describing someone as having a big voice, there are several synonyms that can be used. Instead of saying someone has the "most big voiced" voice, you could use words like booming, thunderous, sonorous, powerful, resonant, or majestic to convey the same idea. Other options might include deep, rich, or full-bodied. Ultimately, the choice of synonym depends on the tone and context of what you're trying to communicate. Whether you're describing a singer with a booming voice or a public speaker with a powerful presence, there are plenty of synonyms to choose from when trying to find the perfect adjective.