IF you want to get more-indepth into the acoustics, Carpet is actually not usually preferred, though in most theater settings it's the only way to go, aesthetically speaking.
Carpet is excellent at taming echos. Problem is, that you usually only hear echos as high-frequency reverberation. Carpet is absolutely useless for absorbing lower frequencies, and ideally you want to lower the reverb to a correct level across ALL frequencies, not just the highs.
Some prefer hardwood floor, and an absorptive ceiling, since you can have many inches thick of absorption and also diffusion up there that you can't really walk on the floor

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Just realize that carpet *will* affect the acoustics of the room, but it is usually *not* the best desired treatment. You should take this into account if adding other absorbers, because you may end up absorbing way too much of the highs and not enough of the lows.
If you dont go without carpet, some area rugs for the first reflection points off the floor wouldn't be a bad idea though.