Sure
The Blaupunkt stock speakers (SL version here with the premium stereo system) has the speakers built into a hard plastic frame then attached by 3 bolts into the door skin. The stocker speakers are 60 watts each and 20RMS.
since my speakers are fairly deep I had to use a spacer, so I cut out the SL speakers(they are attached by 6-8 plastic legs) after I had them removed all you have remaining is a circle spacer.
I then put door insulation are the cricle and I attched the speaker using 4 zip ties, the fit is nice and tight with no movement or space for air to come out.
You can also reuse the speaker connectors if you wanted to, but I just cut the plug off and used the wire that was included with my speaker sets.
It is very hard to explain but was so simple to do, I am going to dynamat the doors and when I do that I will post better pictures of what I did to mount the speakers.