CSW unrecognized

[fixtillbroke]

I first got involved with this forum when my one of Cizek Model Ones came unglued. I took it into the factory, just across the river from Watertown Square, to get it looked at. They immediately removed the woofer and replaced it with a new one off the production shelf. They insisted on testing both speakers. They were working great, but a couple years later, the foam rot showed up. I found out about this forum's founder and his speaker repair operation in his home basement. His skills and materials gave the Cizeks life again till I had to sell them, only due to their size burden. 

Recently my father died and his original Cambridge Soundworks Ensemble speakers were part of his audio gear. They were assembled a short walk from that same building where the Cizeks were in Newton. I was told they were put away because they sounded bad and discovered the woofers had vinyl surrounds that had cracked and split away from the cones. Very shiny material. The center also had no dust cap, but rather a steel diffuser that looks like an electronics cooling fan! Since I now do my own surround repairs, they now have new rubber and are ready for use. I just wonder if this unique center fan thingy is common or only in some years, and what was the goal that Kloss was going for? The sub cabinet was designed to be hidden and placed for optimum bass response, so what would the deflector provide?

[Pete B]

The "fan thing" is a heatsink, does it move with the cone?

I'd guess that it is thermally connected to the voice coil.

[Guido57]

There were a few versions of this woofer.  I believe the latter versions did not have the heatsink.  The surround material also changed over time.  My original surrounds appeared to be foam that had a weird failure: they devolved into a non sealing goo that kind of held its shape.  Couldn't see the problem without taking off the grill, same with the satellites' midrange.  New surrounds and caps for all.  Note: IMHO a set in good shape sounds a lot like NLAs.

[speaker dave]

I'm guessing the fan blade is tied to the core pole.  We did a similar heatsink on a 10" woofer used in a couple of Snell models.  It did lower the VC temp a little but we had to deal with air noise issues since you were essentially loosing the dustcap.

[bikdav]

Some of the later 8 inch subwoofers had this. This was supposed to aid in keeping the voice coil from overheating. I don’t know how effective this was.