Dude, where's my bass? Oh, lost to stiffened rubber surrounds...who knew?

Does anyone think there would be a difference in repair procedure on rubber surrounds vs. foam???

I have a set of Genesis III's and two of their Servo12's-- all of the woofers used foam surrounds and after about 12 years the foam began to fail on many of them-- used a local speaker restoration specialist and he recommended using a light rubber replacement surround instead of the foam-- I went with that and did them all-- that was more than ten years ago and they all sound great to this day. I never noticed any degradation in the sound quality-- and in the case of the subs I think it made a small improvement. Would do it again in a second if I had to. 

Well, thanks to all the responses pointing me toward on-line sources for either speaker/driver repairs or replacement surrounds.  After considering shipping costs, repair and materials fees, etc, I opted for a first-pass DIY approach, as I am a bit of a hobbyist and have quite an array of tools, what-have-you to do the necessary remove/refit of new rubber surrounds.  Went on-line to SimplySpeakers.com, ordered two repair kits (four surrounds and adhesive) for 6.5in B&W cones.  Removed the perished original grey rubber surrounds, cleaned cones, then followed directions to correctly place and glue up new rubber.  Everything went smoothly, then connected up speakers to some old vintage gear (Carver) with existing Monster cables, just for initial evaluation...WHOA!  bass is back, with a vengeance!  Put on some bass-heavy tunes, can't believe the difference...complete restoration of dynamic, full-range response, w/o any optimisation.  Also nulled out tone controls, and ran speakers at moderate volume with a ton of Trentemoller to really work the woofers/mid-range drivers.  Seems as though sound improved after a couple of hours, then  leveled out.  Whatever, I'm so pleased that the CM-4s, as Lazarus, have arisen from the dead!  Will be relocating back to HT room, pairing with sub for some cracking LFE.
Now, about those cable evaluations...(?)

Congrats on the resurrection! 

As to the cables, don't bother and don't waste your money.   Cable is cable./s   Just wanted to get that out there before anybody else!

Actually, I stand by my recommendation in your other thread in Cables.

@johnk --

... system I am running as I type uses drivers from the 1950s 60s 70s all are orignal all are in spec. They sure dont make it like they use to.

Would you expect new, more or less equivalent drivers with the same diaphragm (i.e.: paper) and surround material (pleated cloth accordion surround) to last as long as those older drivers you’re referring to? The bass horn drivers of yore are almost a breed onto their own that are rarely made the same way today (i.e.: with their typically smaller and lightweight VC’s and light diaphragms), though a few examples that are made today could be GPA, Vitavox and Crites (the K33E "clone"). Moreover, bass horn drivers are very often hidden to some degree behind the horn they’re loading, and so aren’t as readily exposed to sunlight and other atmospheric conditions. I would assume this also to be a factor in extending their lifetime compared to direct radiating units?