Well, THERE's your problem!

[Kalessin]

Cambridge Soundworks was founded by Henry Kloss in 1989 in Cambridge, MA, one of the many local audio enterprises of the mid-20th centery incluing Acoustic Research, KLH, and EPI/Epicure, the original H.H. Scott, Apt Holman, etc.

The original CSW products were sold by mail only, with a 90 day (or maybe longer) return period for a full refund. The original Ensemble (and the thread-starting photo looks like Ensemble satellites) was close to the first if not the first sub/sat system, with two 8" woofers in slim cabinets and two small satellites. They were sold with wires included for connection in parallel, and instructions and hints on how to distribute the four pieces around the room.

The bass cabinets had a low-pass crossover at (if I recall correctly) 120 Hz or maybe 100 Hz, and the satellites a corresponding high-pass crossover. While many bass cabs were finished in plastic laminate (like a countertop), the satellites had a rubbery painted finish with a product called Nextel which deteriorates and gets sticky and gunky after three decades. The finish can be removed with denatured alcohol, and replaced with spray-on pickup truck bed finish or any other finish.

The driver surrounds were either butyl rubber (which lasts a long time but which can stiffen) or foam, which usually disintegrates but can be replaced.

I have a set of original Cambridge Soundworks Ensemble which I've been meaning to restore when I have time. They probably don't test very well, but they may make good workshop speakers. I've also got a set of the "Soundworks" computer speakers, which sold HUUUUGE in the early days of multimedia, with a powered 5" ported subwoofer with a 5w amplifier and two little satellites with 3" drivers and 4w amplifiers inside the sub.

CSW was eventually bought by Creative, the maker of sound cards, and the products cheapened out of existence. The name survives on some portable bluetooth speakers.

 

[mhardy6647]

In a blatant case of synchroniciry -- I just refoamed a pair of CSW Sixes last week.
Later Sixes had (I am pretty sure) rubber surrounds, but this US (Newton, MA) made pair had foam surrounds, and they were at the point of failure.
I picked these up at a church fleamarket in Acton, MA, probably 15 or 20 years ago.
Kloss and his cronies had a way with cone tweeters.
There's a nice XO do-over for the Sixes published by audioXpress in 2001 (FWIW).
Sorry, I know this is off-topic -- but not entirely off-topic!

DSC_0369 by Mark Hardy, on Flickr

DSC_0365 by Mark Hardy, on Flickr

 

[Kalessin]

In a blatant case of synchroniciry -- I just refoamed a pair of CSW Sixes last week.
Later Sixes had (I am pretty sure) rubber surrounds, but this US (Newton, MA) made pair had foam surrounds, and they were at the point of failure.
I picked these up at a church fleamarket in Acton, MA, probably 15 or 20 years ago.
Kloss and his cronies had a way with cone tweeters.
There's a nice XO do-over for the Sixes published by audioXpress in 2001 (FWIW).
Sorry, I know this is off-topic -- but not entirely off-topic!
by Mark Hardy, on Flickr

Nicely and neatly done!

It appears that CSW changed back and forth with surround types, probably going with whatever was cheaper from suppliers. Now I really do need to find some hours of spare time, dig out my Ensemble set from storage, and get the restoration going...

 

[mhardy6647]

Nicely and neatly done!

It appears that CSW changed back and forth with surround types, probably going with whatever was cheaper from suppliers. Now I really do need to find some hours of spare time, dig out my Ensemble set from storage, and get the restoration going...

That's the old surround
I will show 'after' photos -- I have them, but not downloaded (yet). The refoam went well with Rick Cobb's excellent replacements.
That was probably the "newest" (it's all relative!) pair of woofers I've yet refoamed.

 

[Kalessin]

Well, huh!

When you get the chance, please do upload.

Nearly all of the surrounds that I see needing work look like tattered bits of foam held together with dust bunnies...

 

[McFly]

This reminds me of almost every car speaker (mainly jap fleet here) I removed for upgrades in the 90s/00s. Only in the late 00's did we start to see drivers with rubber surrounds being used. Man it sure entrenched a deep hatred for foam surrounds in me. If the Japanese were diehard audiophiles, they sure werent working at the car manufacturers...

 

[MrPeabody]

It's like people making pronouncements about Class D vs. Class AB
There are different sorts of 'foam' and different sorts of 'rubber' with significantly different properties, including the way the age in different environments. Some rubbers will stiffen and crack, especially in the presence of specific environmental contaminants. Some foams will fall apart. Other foams and rubbers will remain apparently unchanged after decades. You could make sweeping statements about 'plastic' too, and be just as wrong.

Environmental differences are also likely a factor. I have some anecdotal evidence that suggests that polyurethane foam deterioration is associated with the release of ethylene glycol into the air, from cigarette smoke. Over the decades I've known of multiple cases where foam had rotted excessively, both speaker surrounds and foam padding on headphones. In the cases where I observed this, at least one moderately heavy smoker lived in the home. On the flip side, I bought a pair of the last large Advent (5012?) sold in the early '80s (around the time of the Jensen takeover) and used them for twenty-seven years, on average maybe five hours a day. When I eventually sold them after nearly three decades there was no evidence of foam deterioration.

Ethylene glycol (antifreeze) is a solvent that is used routinely in industry for various applications to include the breakdown of polyurethane. Glycols are also humectants, i.e., compounds that absorb and retain moisture, which is why nowadays glycols are among the commonly used additives in cigarettes. Including ethylene glycol. This has apparently been the case since the early '70s. A low concentration of vaporized ethylene glycol, even at a level that would be difficult to detect, given enough time, would mostly likely lead to the slow, gradual breakdown of polyurethane foam kept in that same closed environment.

 

[MrPeabody]

With speakers in particular everything is about tradeoffs. So it is with the cone vs. dome tweeter. That cone tweeter is most likely larger in diameter than most modern domes, as is usually the case with older cone tweeters. As such, they were inherently more directional, which meant that they provided a better match in directivity with a woofer or large midrange, vs. a smaller dome. They also generally had greater excursion compared to modern domes, which further promoted the use of a lower crossover point. Most likely this cone could be crossed lower by at least a full octave, compared to a typical modern dome. The downside is that a cone tweeter like this one is most likely as directional at 4 kHz as a typical modern dome is an octave higher. In a school of thinking where the off-axis upper-treble is not musically important, this cone tweeter would make perfect sense. That all said, if I were designing a two-way speaker, a cone tweeter like this one wouldn't be my first choice. But if I were designing a two-way speaker with a very big woofer, it would not be a bad choice given that it favors the lower crossover point that the big woofer would require, such that it won't be excessively directional at the crossover point. Nowadays hardly anyone would even consider building a 2-way speaker with a really big woofer. No longer vogue, for a couple of reasons, one of them subwoofers, the other being the preference for floor-standing towers using multiple small woofers. There has been a lot of change in the philosophy of speaker design since the early '70s. Woofer/subwoofer drivers suitable for acoustic suspension application are virtually nonexistent in the modern era. An interesting project would be a 3-way with a small midrange similar to this tweeter but larger, combined with a small dome or maybe even - dare I say it - one of those ribbon thangs that look like little tiny bathroom heaters.

 

[mhardy6647]

Well, huh!

When you get the chance, please do upload.

Nearly all of the surrounds that I see needing work look like tattered bits of foam held together with dust bunnies...

I was getting ready to pass these along to our (adult) son, who is now co-owner of a home (with his wife ) and I figured I'd better check them out. I touched the surround and it started to crumble.
Mind you, I had listened to them for a couple of days at that point! The surrounds on both woofers were in that mummified state that some will attain. These have been in storage for a decade or so. I hadn't even realized they were foam 'til I popped off the grilles (which requires a little finesse on the CSW Sixes due to tight clearance around the frame of the grille and the cabinet).

 

[Kalessin]

With speakers in particular everything is about tradeoffs. So it is with the cone vs. dome tweeter. That cone tweeter is most likely larger in diameter than most modern domes, as is usually the case with older cone tweeters. As such, they were inherently more directional, which meant that they provided a better match in directivity with a woofer or large midrange, vs. a smaller dome. They also generally had greater excursion compared to modern domes, which further promoted the use of a lower crossover point. Most likely this cone could be crossed lower by at least a full octave, compared to a typical modern dome. The downside is that a cone tweeter like this one is most likely as directional at 4 kHz as a typical modern dome is an octave higher. In a school of thinking where the off-axis upper-treble is not musically important, this cone tweeter would make perfect sense. That all said, if I were designing a two-way speaker, a cone tweeter like this one wouldn't be my first choice. But if I were designing a two-way speaker with a very big woofer, it would not be a bad choice given that it favors the lower crossover point that the big woofer would require, such that it won't be excessively directional at the crossover point. Nowadays hardly anyone would even consider building a 2-way speaker with a really big woofer.

Since I have the set sitting in storage, and there's all this posting activity, I'm now getting the urge to restore my set to investigate the sound of this, ah, retro-audio.

The work will probably consist of replacing the surrounds on four drivers (mids and woofers), stripping the turned-gooey finish off of the satellites and putting on a new finish, checking the components in the crossovers, and getting them set up to compare to some other speakers around my house. It might be an exercise in retro-audio comparison, but these did sound pretty good, back in the day.

If I do get all of this done, I'd also have to consider shipping at least a satellite to Amir for some modern measurement.

 

[Chrispy]

Had some of those, but yes the foam died in the end. Didn't think they were worth repair, though, just chucked 'em.

 

[MarkS]

An interesting project would be a 3-way with a small midrange similar to this tweeter but larger, combined with a small dome or maybe even - dare I say it - one of those ribbon thangs that look like little tiny bathroom heaters.

Sounds like the BMR Monitor ...

 

[Robin L]

It's like people making pronouncements about Class D vs. Class AB
There are different sorts of 'foam' and different sorts of 'rubber' with significantly different properties, including the way the age in different environments. Some rubbers will stiffen and crack, especially in the presence of specific environmental contaminants. Some foams will fall apart. Other foams and rubbers will remain apparently unchanged after decades. You could make sweeping statements about 'plastic' too, and be just as wrong.

And in any case, replacing a foam surround is no big. If I can do it, you can too.