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

Double posting...if there is a moderator, pls remove...cheers.

Speaker cones do age, and the surrounds even more. These speakers were introduced quite a while ago, so they may be fairly old. Degradation is faster in the sun or close to a heating system, of course.
Some people manage to replace the surrounds, but I would not expect the speaker to sound exactly like the original.

Check with Bill LeGall at Millersound (http://www.millersound.net/index.html).  He can advise you as to whether it's cost-effective to repair your speakers or not.  Dick

There are professionals that can replace the surrounds and the speakers can sound as good as new. You would just need to do a google search or I don't doubt that someone here on Audiogon can make a recomadation as to a person/business/website.

Get the surround repaired rubbers lucky if it lasts 10-15 years 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.

I've had several friends get speaker surrounds fixed they will sound good as new once broken in.
It maybe a good time to check crossover components too .

The most difficult to replace surrounds are on the midbas and mid drivers.

Difficult as matching back to the original sonic presentation, as it was originally designed to be...becomes very difficult.

Not so bad with generic drivers but B&W would not be generic drivers or generic surrounds attached and glued and built in a generic way. The opposite in fact. at least in modern designs. Some surround types are not made for nor available to the repair market. For older drivers this is not as much of a problem, as some of those cone/surround considerations have become mainstream. But not always. Cases are individual, and require individual investigation.

On the high end midbass and mid drivers this becomes the core issue.

In the best cases it is minor, as problems go and in the worst cases, it can be undoable or so sonically shifting... that it is no longer like the original speaker.

Someone who can judge that correctly in a mid bass or mid scenario, is almost (partially, at least) a driver designer in their own right.

So you can’t just and should not simply buy a surround anywhere, from mister reseller who sells surrounds that ’fit’.

Look to matching things up correctly, via a specialist who knows what is what. And research the specialist. Make sure the research results of people’s satisfaction is built out of people who can understand the subtleties in difference. Look for the intelligent and learned opinions and feedback.

Ie, a pile of opinions without data on the intelligence and learned aspects of the opinions means exactly squat, but most people don’t look close enough for that, and so..mediocrity ends up ruling the day. Quantification and qualification of the given data leads to the better conclusion, as it does in all analysis...

Another +vote for Millersound.

Thanks all for your suggestions...will contact Millersound to arrange for refoaming...cheers.

+1 on the MillerSound recommendation.  He has replaced the surround on a car speaker, as well as replaced the surrounds and restored my original pair of New Large Advent Utilities that I got new in 1978.  I couldn't bear to part with them.  They now look and sound wonderful.  Bill LeGall is a consumate professional and a really nice guy.  Highly recommended.  Reasonable prices, too!

+3 on Millersound.

Bill listened to my speakers, and immediately felt the rubber surrounds hamstrung them.  After he worked his stuff on them, he had them soaring like eagles.  He's a master at getting a driver to work optimally and actually make music

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?

Re: SimplySpeakers replacement surrounds:  the material of the new surrounds differs from original in color (black, slight shine), more supple, and "soft" to the touch.  I emailed SS to enquire about the composition of the replacements, but haven't heard back.  Maybe it's a proprietary formulation, who knows?  But, for all that, just great gear.

Hard to tell how things will really age and I honestly do not think that modern drivers will age as well as some vintage has. I have modern drivers in my scrape piles many killed by foam degradation modern plastics are used in most everything and some of those as they age become gummy and break down into the VC. 

I have a pair of KLH Model 2, they have to be over 30 years old and the butyl surround is still soft and supple...  so you never know....the environment plays into it too.  

That's great you were able to DIY