Resonances in the body of a musical instrument are an essential part of defining its nature and quality. The opposite is true of a loudspeaker.
Cabinet panel resonances are a significant cause of sound coloration. Heavy bracing of a typical MDF enclosure can help reduce enclosure flex but at the cost of increased energy storage and damping factor. Although a welcome attribute for midrange outout, over damping is detrimental to bass performance (high energy storage, low wide Q and low resonances).
MAGICO has spent many years developing an enclosure system that successfully balances the 3 elements that constitute a proper loudspeaker enclosure: stiffness, mass, and internal damping.