Yea, it's pretty easy to replace the foam surrounds on drivers, provide you
find the bits that fit and are willing to do some glueing. If you start swapping
out the drivers themselves with replacements, you're pretty much starting
from scratch and just using a Mc box and crossover to build your own
speaker in -- which if you're unreasonably lucky might work out other than
poorly, but would almost certainly be a bad plan.
Have to admit, I've actually done it both ways. Had some unidentified
speakers with corroded surrounds that I swapped out with some from rat
shack in college (actually pulled and replaced the 12 inch woofers, I mean).
The speakers themselves where worthless, so no loss, but I nonetheless
thought I was super clever. They worked. For a little while. And then they
stopped, and there was nothing to be done about it. Actually ended up
pushing them out of the window rather than carry them down the stairs.
Better luck, older pair of infinity speakers, also with totally disintegrated
surrounds on the woofers, I got a kit to replace the surrounds from some
spot in CA and they're now as good as ever. You can find reconing kits as
well if your cones are damaged, but sounds like all you need are new
surrounds.
Makes sense to start with the manufacturer, but you may also be able to find
kits with the proper sized surround and apoxy on the intertubes if it comes
to that. But have to agree, wouldn't just start swapping out drivers. Having
learned the hard way, there are much better options. Best of luck.
Oh, further thought -- I have actually replaced drivers on a pair of Thiels, but
in that instance I in fact had fried the coaxial tweeter/midrange and the good
folks at Thiel were kind enough to send me a replacement driver matched to
my speakers. So, you can certainly replace drivers -- but I wouldn't do it
with anything other than the drivers by McIntosh for Mcintosh. In all events,
sounds like here there's a much simpler (and cheaper) fix....