Hi,
I wouldn't recommend using a single IW85, as the drivers are similarly sized but definitely quite different. The original M&Ks used all danish drivers.
I believe the new MKsound use chinese units. Additionally, the SW-85s were typically installed with a kit that impacts performance as well.
I still assemble the original M&K speakers using the original cabinets, drivers and crossovers. I can assemble S-150 / MPS-2510 LCRs, as well as SS-150, SS-250 / MPS-2525, and MPS-2575 tripole surrounds.
Unfortunately, I can't send a replacement driver. I did a bit of that earlier to help folks out, but I need the remaining parts to fill the enclosures on hand. I also can't recommend eBay, as many parts from the bankruptcy sale in California circulate there. Most of those drivers were QA rejects. I bought cases of original drivers that were never delivered, so they were not from the auction.
However, I happen to have a spare, new in box, SW-85 left from installing the ceiling speakers in my basement 11.1 system. I would be willing to swap it for your damaged SW-85 and cash. That way you can use the original installation and use the grill from the original so the colors match. I can send pics if you are interested.
If you want to discuss it, my email is
chaswerner@gmail.com
I still feel the original Miller & Kreisel equipment is superior to almost anything for multichannel HT use. There was a reason almost all THX film studios used those speakers to master movies. Your SW-85s are smaller, but use the same drivers as their bigger relatives.
I hope this helps,
charlie