With all due respect to your above comment, when Naim develope(d) the speaker it was not with the view to "right we have made this speaker with all its special suspension, isolation, pistonic suspension for BMR, now what do we cover the drive units with." It was devloped as as a whole unit, ill bet the drive unit covers were not an afterthought, and are part of the design, the way it sounds works etc.
Many people wont know that there are two tiny ports in the base of the speaker which " vent" and the foam under the bass grills will all affect complance and speed and return of the bass drivers.
Ive always been of the opinion more clarity does not mean more music.
David.