Possibly.By drilling a nice 1 inch diameter hole in the mount, just to make access a bit easier, have I compromised the audio performance as pretty obviously it is no longer sealed! Thanks.
In fact, yes, but will you notice, probably not!
I made gaskets from closed cell foam to seal the drivers to the adaptor, then reclaimed the factory foam to seal the adaptors to the door. I then drilled a pair of holes and Dremeled a slot between them to make a figure of 8 hole that was a tight fit to the cable, which I sealed with some bitumen stuff from a scrap of sound deadening. This seals the speaker up nicely, but the door is still full of holes anyway so quite possibly overkill! I only wanted to go into the door once. As it turns out I was kidding myself, been in at least 4 times but that's another story!