You would have to redesign the cabinet, and cross over if you put in different brand higher spec- matched drivers. For their magnet,frame structure is different
A DI ultimate reference would be I would estimate around $18k
To be close to the competition that sells for $40k.
I think this is an honest assessment if I were coursing parts .
Like a 3 way speaker I built ,for sale grade A Birch ply sonivly is noticsbly more solid ,and sonivly better, the DI dpeaker uses MDF .one major reason these $$ big money speakers have such low noise and tight Bass is composite ,materials
Machined Aluminum and high tech - black hole sound absorption for example
,and the Entire crossover in its own isolated chamber. The Double impact
Has the Crossover in the same environment as the drivers, that is an error .
For the crossover picks up vibration as is generated back as distortions ,small may be but cumulative. These are just examples .even hook up wire .I seen a great demonstration with regular decent ,kimber,cardas hook up wire $ 3 a foot
And the excellent Verastarr Copper foil ,in a vapor speaker .The verastarr was $10 a ft .thst being said the speaker was much more detailed in transparent.
It all comes down to how much do you want to compromise in the speakers $$ price, performance .All parts choices are cumulative in the final voicing
Of it's design.