The quoted research points to two self evident features of dome material they may effect frequency response and dispersion ? Resonances are not in that research but if we add that , what’s more ?
There is no homeopathic property that imprints some “ aluminium dome sound on everything “ ? Like I thought in the past .
Implementation differences then ? hard dome will spread hf energy differently . Wonder if all speaker designers always been on top of thier game , making the balance of direct and indirect sound make sense ? Making the transition designing speakers with a soft dome vs a hard dome ?
To compound the matter dome material including Alu ( before be and diamond ) is a marketing property and some designs makes you hear that
a proper implementation might instead give a subtle improvement that don’t stand out that much. Suppose it works the other way to with a silk dome ?