@sounds_real_audio: Incorrect. The primary and most important reasons for and benefits of bracing is to:
1- Minimize the ability of the enclosure to expand (like a balloon being blown up)---thereby propagating sound---in reaction to the internal pressure created within the enclosure when the drivers move inward. That pressure is extreme, like a pot of boiling water with a tight lid on the stove with a high flame. Wall-to-wall braces prevent the enclosure from doing that. Again, look at how Jim Salk braces his subwoofer enclosures, and how Magico braces their loudspeaker enclosures.
2- Raise the resonant frequency of the enclosure panels to that above those excited greatest by the most problematic of the enclosure frequencies---the low ones (bass).