Apogee Acoustics is now making replacement EMIM diaphragms of very high quality which will fit all of the Reference series speaker plus Betas/Gammas/ Deltas, IRS series, etc. Check out this link for details, pictures and ordering information. I have these in my RSIIb speakers and they sound far better than the originals!

http://www.audioworld.com/sw/Forum1/HTML/008160.html