This is a complex subject. The fundamental recipe for the cabinet after choosing the material and shape is to brace, glue, screw and add absorption. The devil of all of this is in the details.

The purpose of a cabinet is to prevent the sound from the back of the drivers from escaping into the room. One can say choosing MDF sucks because most of the sound goes right through it. Hardwood appears to solve that problem by trapping the sound but now the back pressure has to go somewhere so, presuming the cabinet is epoxied, screwed and sealed, it escapes out the drivers which of course interferes with the sound. Hence some type of damping is added to absorb the sound.

Usually the damping is loose but not necessarily. Gluing heavy damping material to the cabinet increases absorption but increases mass which increases the cabinet's resonant frequency. Bracing can then be added to further increase the resonant frequency so it's not objectionable but this has to be carefully designed as well because you can't just brace anywhere and with anything.

Using hardwood usually means having to add heavy damping that is glued to the walls and multiple hardwood braces to get the resonant frequency above 1 KHz. This of course is very expensive. Hence why MDF is chosen - less mass, lower resonant frequency and a bit of fill.

The bottom line is the designer should have considered all of this and selected the right materials and construction methods to optimize the speaker as a system. So don't mess with it...yet. Build this baseline design and then build others if you want to compare with the baseline.