"DoN. Nichols" wrote in message
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In article ,
Harold and Susan Vordos wrote:

"DoN. Nichols" wrote in message
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[ ... ]

[ ... passive radiator ... ]

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Hmm ... is there perhaps some kind of baffle to delay the sound
from the driven speaker to the passive one? But that would likely make
it peak at certain frequencies and cancel at others. (But maybe this
would happen at frequencies that those speaker elements were not fed,
being more the job of the midrange and tweeters.)

No---no baffles of any kind. I've had the woofers out of all of the
speakers to be reconed. They have a foam rim that eventually
deteriorates
and must be replaced. Heavy passages can actually tear them apart
completely, although mine have never gone that far.

I've seen that happen. A problem with pretty much *any* foam
rubber over time, and a foam rim does give significantly better
compliance than the tar-soaked paper or cloth ones with multiple pleats.


When I bought our second pair of S8R speakers, which I found listed in the
newspaper, they were being sold because of the foam failure, along with the
cabinets having been thoroughly abused. I wasn't concerned about the
woofers, knowing reconing wasn't a big issue. I was encouraged to know
that they were still the factory original foam, which was completely
different from the replacements, even from JBL. The price asked for the
speakers was a give-away for those that had an understanding of the value of
the components.

What came as a real surprise to me was when I inspected the woofers in the
Paragon. While I've been talking about them as if they have the same
speakers as they S8 system, they are really the next generation of speakers,
so their identifying numbers are different. Instead of the 375 driver for
the midrange, they use a 376. As far as I know, the chief difference is
modern magnet technology as opposed to the old Alnico technology. The 375
drivers use a 28 pound magnet, along with a 4" ribbon wound voice coil. In
JBL's literature they make reference to the 375 driver's ability to handle
explosive passages in stride. My personal experience in having owned
them since 1966 is they were too modest. Until such time that you've had
the pleasure to play with a set of these giants, I'm not sure you could
understand their capability.

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Great! I presume that there is no grill cloth mounted in front
of those elements.

There is a very light weight black cloth that is stretched tight and
stapled
appropriately. Doesn't seem to create any strange noises, and performs a
fairly important function of masking what's behind the wooden grills. I
think they spent enough time with the design to insure it was a good one,
but I have no way of knowing if it is, or not.

O.K. My comment was because of your mention of watching the
woofer work with heavy passages.


The front cover is easily removed. They mount with four locating plugs
that are a simple press fit. One of my methods of enjoying the system is
to watch the speakers work on heavy passages. That's more likely to occur
when I'm listening to the system instead of listening to music. You likely
understand that nuts like me enjoy their systems in more than one way.
Sometimes the music is secondary.

[ ... ]

She even searches eBay for tools for me -- and has not yet
learned to not say "this one sounds strange" and attract my attention.
:-)

How cool is that? Susan has no clue about tools, but she sure
encourages
me.

Dolores has no idea how to *use* them -- but she is good at
recognizing them. She finally found a cut-style knurler which did not
go sky high (compared to new price), and which fits my tool holders, so
I can start to experience that capability. (Well ... I do already have
one in the form of a long-armed 3-jaw chuck which works on the turret,
but that has a limited travel.

You'll have to enlighten me here, DoN. I've never used anything but the
roller type that impresses, and the old school stuff, not even a scissor
type.

Harold